DISCOVERMORE, SAFELY

CRYSTALBALL 2010NEW ZEALAND MOUNTAIN SAFETY COUNCIL

AVALANCHE MAGAZINEVOLUME 20

PERIODICAL FOR THE NEW ZEALAND AVALANCHE COMMUNITY

NEW

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2 CRYSTAL BALL

AVALANCHE NEW ZEALAND MOUNTAIN SAFETY COUNCIL

11-12 JUNE 2011COPTHORNE HOTEL COMMODORE CHRISTCHURCH AIRPORT

INTERNATIONAL SPEAKERS, LOCAL EXPERTS

AVALANCHE EDUCATION NZSAR AVALANCHE INCIDENT PRE-PLANNING

SOUTHERN HEMISPHERE

CHRISTCHURCH

CONFERENCE

TWO PRE CONFERENCE WORKSHOPS: 10 JUNE 2011

i n f o @ m o u n t a i n s a f e t y . o r g . n zREGISTER YOUR DETAILS

04

05

CONTENTSAVALANCHE NEW ZEALAND MOUNTAIN SAFETY COUNCIL

11-12 JUNE 2011COPTHORNE HOTEL COMMODORE CHRISTCHURCH AIRPORT

INTERNATIONAL SPEAKERS, LOCAL EXPERTS

AVALANCHE EDUCATION NZSAR AVALANCHE INCIDENT PRE-PLANNING

SOUTHERN HEMISPHERE

CHRISTCHURCH

CONFERENCE

TWO PRE CONFERENCE WORKSHOPS: 10 JUNE 2011

i n f o @ m o u n t a i n s a f e t y . o r g . n zREGISTER YOUR DETAILS

CONVENOR’S VIEW AND PERSPECTIVES

AVALANCHE EDUCATION FOR 2010

06AVALANCHE EXCHANGE,OTAGO GRADUATES 2010

08 BUSH CREEK BY RUSSELL CARR

09 BURIED BY AN AVALANCHE

10 REGIONAL SEASONAL SUMMARIES

22 AVALANCHE SEARCH DOGS

25 EARTHQUAKES AND AVALANCHES

31THE HELMET DEBATE

33THE OUTCOMES MODEL

36THE WWW.AVALANCHE.NET.NZ RE-DEVELOPMENT

37 CRYSTAL BALL SUBSCRIPTIONS

2

4 CRYSTAL BALL

WITH THE NEW ZEALAND

WELCOME TO SPRING

2010MOUNTAIN SAFETY COUNCIL

THE CRYSTAL BALLDecember 2010 Issue 20 Vol 5The Crystal Ball is created twice a year by the New Zealand Mountain Safety Council.Submissions of articles, photographs and illustrations are welcomed.

Please send to:

ph: +64 3 371 3724 or fax: +64 4 385 7366e: andrew.hobman@mountainsafety.org.nz

For advertising enquiries contact:

ph: +64 3 371 3724 or fax: +64 4 385 7366e: andrew.hobman@mountainsafety.org.nz

EDITOR: ANDREW HOBMAN

DESIGNER: SAMANTHA CAIRD

Welcome to the final issue of the Crystal Ball for 2010. This has been

a very busy year for all involved with the Mountain Safety Council

Avalanche Programme. We all breathed a collective sigh of relief at

the end of the winter, after an avalanche fatality free season and

hope this continues through the summer climbing period.

It was a variable year for snow- fall but nature still kept us on our

toes. There was an early start to winter and a few incidents in the

Southern Lakes region, then we progressed into a lean patch through

the middle of the season, an Earthquake for the Canterbury region

and finally the snow came, just as the ski areas and heli ski operations

closed. Skier numbers at the club and commercial fields were down a

little from last year but by all accounts, people heading out of bounds or

into the backcountry were up. The international trend towards greater

numbers of people venturing off piste seems to have been emulated

here in New Zealand and the Mountain Safety Council is striving to

communicate with these people on all levels. Good progress has been

made on the re-development of the web site www.avalanche.net.nz

and an exciting new model for the Info-ex. Both of these will offer the

avalanche community the latest advances in computer technology

and provide much more robust and interactive programmes. Planning

for the Southern Hemisphere Avalanche Conference is well underway

with a great line up of speakers and topics to inform and entertain.

But most importantly, the dinner menu and refreshment options have

been sorted out and the raffle and spot prize pool is growing.

I hope everyone had a good winter and that you are enjoying whatever

the off season brings you.

Hobbie

ANDREW HOBMANAvalanche Programme Manager

NEW ZEALAND

Chief Executive Officer: DARRYL CARPENTERChairman: ROSS MEDER

THE MISSION OF MSC’S SNOW AND AVALANCHE COMMITTEE: To provide expert advice and support to the Council on appropriate

strategies to foster public safety in snow environments

To oversee the training, assessments and qualifications of instructors to ensure that national standards are maintained and enhanced

To oversee the professional training programmes of all providers as required

To monitor, research and review trends in snow and avalanche activities to ensure the Council remains the leading authority for safety in this environment

All material produced by New Zealand Mountain Safety Council isconsidered to be in the public domain. As such, all materials may bereproduced for research or classroom use. Permission is also granted for useof short quotations, figures and tables in scientific books and journals.

Well what can I say about the 2010 Winter? It has been and left its

mark. Many of us are probably reflecting on what was a pretty average

winter by now, whilst others have it as a distant memory as they head

for a Northern Hemisphere winter. The one thing that will stick in my

mind, is how harsh Mother Nature can be. Just when she seems to be

dealing the goods out, we get a rain event that brings us back down to

earth. Typical of a developing La Nina pattern really! Looking from the

glass half full, there was the odd day of great powder skiing mixed in

that made it all worth while. You just had to be in the right place at the

right time to get it. To me, that’s one of the reasons why avalanche

professionals are so passionate about what we do; sometimes we

just put ourselves in the right place to take advantage of the great

conditions that Mother Nature provides, safely of course!!!

Taking over the Convenor’s role from Hamish McCrostie at the end of

last winter initially came as a bit of a surprise to me, but in the same

breath I felt honoured and excited to take on the challenge. Personally

+SNOW AND AVALANCHE CONVENOR’S VIEW:“PERSPECTIVES”+

I consider myself a very motivated person and the role of Convenor of

SAC is to have the big picture in mind and to drive strategic vision and

direction for snow and avalanche related activities. Also I feel we are

entering a new exciting era for the Snow and Avalanche Committee;

there are significant changes in the wind with some new very exciting

initiatives that we can adapt simply into our New Zealand system

and environment. On the flip side, one of our biggest challenges is

communicating effectively with backcountry users. This is something

that the whole snow based industry must take ownership of and

collectively address.

The Convenor’s view will regularly be in every issue of the Crystal Ball.

I would like to use this to discuss future initiatives or strategies and

would welcome feedback, discussion and debate on any of the topics.

Cheers

CHRIS EMMETT

6 CRYSTAL BALL

One of the Mountain Safety Council’s primary strategies for promoting

people to get into the outdoors, safely, is the education programme.

The MSC Avalanche programme delivers and facilitates a progressive

syllabus from recreational one to four day courses through to the

professional Stage 1 and 2 courses. The programme also maintains and

revalidates the instructor pool and is involved with the development

and moderation of course content.

The winter of 2010 was another successful year for education delivery.

The MSC branches and Ruapehu Alpine Lifts (RAL) ran 29 Avalanche

Awareness courses for 329 people, and 38 outdoor recreationalists

benefited from the six Back Country courses. International statistics

show that the numbers of people taking advanced recreational

courses is about 10% of the number taking the entry-level courses

and our totals mirror this. Having said this, we see plenty of room for

participant growth in both of these courses with a marked increase

in the Back Country course. We aim to achieve this through a more

co-ordinated national and international advertising campaign, the

redeveloped web site (www.avalanche.net) and by extending the

participant focus to groups such as hunters, SAR volunteers and DOC

staff. The Polytechnics and Outdoor centres around New Zealand

handle the delivery of the professional level courses (Stage 1 and

2). This winter 114 participants were assessed for Stage 1 and Otago

Polytechnic continued to successfully deliver the revised Stage 2

syllabus to eight new graduates.

+AVALANCHE EDUCATION FOR 2010+

5

PAINTING BY RICHARD TEUA TUROA SKI PATROL

CONGRATULATIONS TO THE SUCCESSFUL AVALANCHE STAGE 2 GRADUATES FOR 2010. OTAGO

Polytechnic continues to deliver the new and improved syllabus to industry professionals. The redeveloped course incorporates a mentored logbook (Applied Snow Studies), three Theory courses, a 5-day Field Training (FT) course and a final 8-day Integrated Practical Assessment (IPA). The extended programme not only meets the needs of our NZ avalanche industry but brought us into alignment with international educational trends.

For information on the course, contact Barbara Emmitt (Avalanche Programme Administrator) at 0800 765 9276.

+THE NEW ZEALAND AVALANCHE INFORMATION EXCHANGE +

The Info-Ex provides a daily exchange of technical snow, weather,

avalanche and terrain information between subscribers who actively

manage avalanche hazards. The Info-Ex also serves as one of the

key sources of data used by the MSC Avalanche Centre’s avalanche

forecasters to produce and verify their daily advisories.

Over the past winter, we have been working hard at developing a

model for a better information exchange between industries and

professionals working in avalanche terrain. The existing system

is based on the sound and underlying principle that sharing safety

information is of a great benefit to organisations and the sector as

a whole, by improving awareness of conditions across the region and

enhancing the ability to manage local avalanche risks. Critical to this

is that the data is accurate, relevant and real time. The MSC’s present

system is at a critical point in its development and/or usability cycle.

The functionality of the site is not conducive to complete data entry

and data analysis is restrictive. In addition, users are requesting

features that are testing the limits of the current implementation

(advanced integration of observations and locations) and its feature

set (snow profiles, 3D mapping etc.).

The solution for many of these issues is to provide a web based tool

that can efficiently record, store and analyze an operations safety

data. This should be the primary vehicle for the recording of daily

operational data to ensure a full and accurate data set. By using a

“Cloud” or web based tool we can ensure that the system remains

progressive and is in real time. It also allows the ability to share

this information with other relevant operations.   For industry, the

documenting and sharing of safety information also satisfies any

Department of Labour requirements.

Powdercloud are a Canadian company who have designed and run

a Web-based (hosted) application that meets all of the criteria and

more. They recognised that, just like us the avalanche industry in

Canada required a programme that could reliably and accurately store

and analyze snow science observations. Their application provides

comprehensive date collection, real-time reports and custom charts,

and dependable services. It has been used successfully in North

America for the past 4 years and is fully tested, running and available

for use by the New Zealand Industry. With other critical features like

zero-maintenance, data security, and a whole lot more – Powdercloud

provides a fantastic solution to our needs!

The MSC have negotiated a very cost effective partnership agreement

with Powdercloud to provide access to their system for the New

Zealand Industry. The licensing cost structure has been set up in a

tiered fashion to balance the size of operations, the volume of data

used and the desire to make the system financially viable to all of the

operations, right down to the very small. Each individual subscriber

will pay an annual license fee that provides them access to the full

Powdercloud package to store, analyze and retrieve all their daily and

historical data. The ownership of the data remains with the subscriber

and they control who and how much data they share. Each subscriber

sets up their own profile including avalanche path or run list names,

staff involved, weather stations, oblique photos, control routes etc.

These are displayed in drop down lists to ensure quick data entry.

Weather, snowpack and avalanche observations can be stored as

Meta and graphical data on 3D maps and can link between the two.

i.e. you can mark the position of a snow pit on the 3D map, mouse over

it for a dialog box or click on it to link with the built in Snow-profile

tool.

MSC staff have been testing and demonstrating the system to the

avalanche industry and presented it to the Ski Areas Association AGM

in November. There has been very high interest in the product and we

are now preparing the final documentation required to implement the

system for New Zealand. Our hope is to have a high percentage of the

New Zealand industry using the program for the 2011 winter.

For more information on the system, please contact Andrew Hobman

at Andrew.hobman@mountainsafety.org.nz.

6

L-R: Karen Jackson, Chris Emmett, Wayne Carren (Instructor),

Kevin Boekholt (Instructor), Pete Ozich, Tony Donaldson, Karen

Corcoran and Julie Robertson. – Instructors not shown; Don Bogie,

Tarn Pilkington, Mark Sedon and Peter Bilous.

8 CRYSTAL BALL

7

8

Picture you will a sky of blue 

And a dessert-scape of snow

When the chips are down and the going’s tough

There’s only one place to go

 

It’s not to the North where the peaks are high

And the fearless dare to tread

Nor to the South where the skiing’s great

But somewhere else instead

 

It’s a place I’ve come to really love

A place to call my own

For once you’ve done some skiing there

You’ll really feel at home

 

Well some they laugh and some they cry

And I’ve seen some that weep

I don’t know why they feel that way

It’s really not that steep

 

But it’s a place just out the back

Not far from Coronet Peak

I guess you know the name by now

It’s simply called BUSH CREEK

BUSH CREEK

RUSSELL CARR - HARRIS MOUNTAIN HELI SKI

10 CRYSTAL BALL

9

An incident which occurred at the Reefs, at Browning’s Pass, last

week, is worth mentioning, as it shows the time, it is possible for

a human being to exist when buried in the snow. Messrs McAlpine,

Bros, the well-known contractors of Sheffield, have undertaken a

contract from the Christchurch Gold mining Company to excavate a

drive – 1000ft or so – and, as they were bound to time, it was necessary

for them to work both day and night, through the winter, a thing not

usually done in consequence of the quantity of snow generally laying

in the ranges. At the time of which I am speaking, there had been an

unusually heavy fall, and Mr George McAlpine and a man named Baird

were at work in the drive. They were to be relieved at 12 p.m. by two

men named Danks and Teague, who started from the camp– situated

a mile and a quarter from the mine – at 11.30 on their way to the

works. To reach this it was necessary for them to follow up a gully,

down which the head water of the Wilberforce flows, traversing a

path 190ft above the stream, which has been cut mostly out of the

solid rock. Some idea of the steepness of the country may be formed

when it is stated that there is a rise of 600ft between the camp and

the mine. When Teague and Danks were some 300 yards from the

drive, they came to a blind gully forming a sort of bay, round which

the road led. This had been so completely blocked by drifting snow

that it necessitated their ascending the mountain some distance to

find a more practicable passage. Teague was just in the centre of the

gully, and Danks, who was in front, was nearly out of the drift, and

was turning round to show his comrade the light of the lantern he had

with him, when there was a deafening roar, and they felt the snow

carrying them downhill at a rapid pace.

PETER DANKS SEEMS TO HAVE DESCENDED FOR A HUNDRED AND FIFTY FEET, AND TO HAVE BEEN COMPLETELY COVERED WITH THE EXCEPTION OF ONE HAND, STRETCHED TO THE FULLEST EXTENT ABOVE HIS HEAD,

on which he felt the cold wind playing when the avalanche stopped. By

the aid of the wind, which carried the snow away when he loosened it,

he managed to dig himself out, and after shouting for Teague without

getting any reply, he struck for the mine, where, after a desperate

struggle, he arrived in a state of collapse and utterly incapable of

speech, until stimulants were procured. Once informed of the state

of things, the younger McAlpine acted with promptitude, and started

to the camp for assistance, travelling down the bed of the stream

to avoid any fresh slips that might occur. He arrived there in a very

short time, and after giving the alarm and changing his clothes – the

trousers of which had frozen hard- he headed the rescue party. All

hands turned out promptly, and, armed with long-handled shovels

sought eagerly for their lost comrade till ten in the morning, when

giving up all hopes of ever seeing him alive, they adjourned to have

some breakfast and make arrangements to have the corpse conveyed

to Springfield. Directly after breakfast another attempt was made to

recover the body. The rescuers must have suffered severely. All the

time there was a bitter cold wind blowing, which lifted the snow up

and carried it along in drifting, blinding clouds. The snow froze on the

handles of the shovels they held to the thickness of a man’s thigh.

Their beards were frozen to their chests, and icicles hung from their

hair and eyebrows – in fact, they were enclosed in armours of ice. Their

attention was directed to a place 300 feet from where the slip occurred

by a terrier belonging to Baird and George Mc Alpine, who had a 1/4in

rod of iron, managed, after trying for some time, to strike Teague on

the leg. He was found at 12 o’clock lying on his back, unconscious, but

with his eyes open. His right arm was doubled under him, but the left

was still working spasmodically, as if trying to dig himself out. He

recovered, and was doing fairly well in a couple of days, and wished to

go to work. To this however, the contractors would not consent, but

generously kept his time good for a week.

CANTERBURY TIMES

7 OCTOBER 1887

+BURIED BY AN AVALANCHE+

10

Another winter season draws to a close as spring pushes itself

once again into the October limelight. The past few months have

not been without incident, but fortunately those that have had

avalanche involvements, have come out unscathed, and we hope

the wiser for the experience.

We are currently undergoing a development phase here at www.

avalanche.net.nz, as we look to improve the methods and

presentation of our avalanche advisories. Expect some exciting new

things for next season as we roll out multi level advisories using text

and graphics to best inform our viewers. There is much work to do

through the summer months to get this ready, but for this year we

would like to thank all the Ski Patrols and Guiding companies who,

without their efforts, our Regional forecasts would not be possible.

We appreciate the time taken by these operations to make available

their keen observations. This enables our Regional Forecasters to

communicate key information for Backcountry travellers to use

when making decisions.

Thanks also to our Forecasting team, who are scattered around the

alpine areas of the country. We value their work tremendously, as

they produce consistent, high standard avalanche forecasts, to help

us all make informed decisions when travelling in the backcountry.

Below are a summary of each regions significant events and trends

over the winter season. Enjoy the reading as well as the looming

Spring touring season, and we hope to continue to cater to your

needs.

We are always interested to hear your thoughts and comments, so

please write to us and let us know how we are doing. All feedback is

welcome. Please write to info@avalanche.net.nz.

Thanks

INFOEX COORDINATOR – GORDON SMITH

+2010 AVALANCHE.NET.NZ REGIONAL SEASON SUMMARIES+

RUAPEHU REGION // TARANAKI REGION NELSON LAKES REGION // ARTHUR’S PASS REGION // CRAIGEBURN REGION // MT HUTT REGION // ARROWSMITHS REGION // AORAKI REGION // MT COOK REGION // WANAKA REGION // QUEENSTOWN REGION

INFO@AVALANCHE.NET.NZ.

12 CRYSTAL BALL11

+TONGARIRO NATIONAL PARK RUAPEHU REGION+

WEATHER High pressure dominated the majority of

July with only a few low pressure systems

bringing small amounts of snow to the region

and relatively cool temperatures. August was

relatively unsettled with a continuing pattern

of mid Tasman low pressure systems which

generally brought warm Northwesterly flow

followed by cool Southeasterly. Early August

brought heavy rain showers to high elevations

in the region with winds from the Northwest.

Mid August, continuing low pressure finally

brought snow to low elevations in the region

with storms depositing 10cm followed by

another 20cm. As the pattern continued,

warm Northwesterly flow deposited 60mm

of rain to high elevations washing away

large amounts of snow at lower elevations.

This pattern of unsettled weather continued

through the end of August into September

with snow showers to low elevations with

high winds followed by heavy rain showers

to high elevations generally losing more

snow than was accumulated. Mid September

brought a relentless low pressure system that

enveloped the whole of New Zealand and

continued to dominate the region with heavy

snowfall to low elevations and gale force

Northwesterly winds which persisted into

the last week of September. This system left

a trail of damage to the ski areas operating

in the region with large accumulations of

snow partially burying buildings and lift drive

stations. Also many ski lifts derailed from

severe gale force winds and intense ice build

up that amounted to 5 feet on lifts and even

caused the failure and collapse of a lift tower.

This pattern may continue into October.

SNOWPACKA generally stable snowpack existed

throughout the majority of July with very

few storms bringing small amounts of snow

accumulating to low elevations leaving

a relatively shallow snowpack. Cooler

temperatures caused the growth of a near

surface weakness in the snowpack on shady

aspects late July but early August, heavy

rain showers to high elevations saturated

the snowpack nullifying previous weakness.

Mid August, low density snow fell to low

elevations and cross loaded onto an array

of slopes facing West through the North

and East with pockets of sensitive slab up

to 50cm deep in places. Heavy rain showers

to high elevations quickly followed melting

and consolidated the old snowpack leaving a

generally stable pack consisting of wet grains

and multiple crusts. These same showers

washed away snow at lower elevations lifting

the avalanche threshold to above 1800m.

Heavy snow showers persisted in the last

week of August loading slopes facing the

Easterly ½ with 80cm of sensitive soft slab

at higher elevations. This quickly cross loaded

onto to slopes facing the Southerly ½ and

remained sensitive. Early September, heavy

rain showers again saturated the snowpack

to high elevations nullifying any previous

weaknesses and causing the snow line to

recede at lower elevations. Mid September

saw the start of significant storm cycle that

continued into the last week of September.

Gale winds from the Westerly ½ continued

to load storm snow onto slopes facing the

Easterly ½ above 1600m creating multiple

layers of sensitive soft and hard slab which

grew to over 3m deep in places. Deep

instabilities remained a concern on these

slopes on the days following however heavy

rain showers to high elevations yet again

saturated the snow surface and refroze

leaving a very strong supportive widespread

crust. Time settled out any remaining deep

instabilities leaving a generally stable pack.

Snowpack observations will continue through

October into early November.

AVALANCHE OBSERVATIONSMultiple Avalanches were triggered by Ski

Patrollers on an array of aspects averaging

from size 1 to 2½. The majority of these

Avalanches were above 1800m and triggered

with explosives while smaller slides were

controlled with ski cutting. Natural activity

was observed early to mid August above

2000m ranging in size from 1½ to 2½

sliding within the storm snow. 2 Climbers

remotely triggered a small size 1 avalanche

above 2300m from a distance of metres late

August. Natural activity was expected late

September however it didn’t eventuate.

DANGER RATINGThe Danger Rating spent little time on

LOW this season with the majority of time

spent fluctuating between MODERATE and

CONSIDERABLE as storm cycles continued

to pass over the region. The rating trended

to HIGH for over a week in the last part of

September as a significant storm dominated

the region for 10 days but trended back to

MODERATE by the end of September.

TRAVEL ADVISORYBackcountry Travellers were advised to

use caution mainly on steep unsupportive

slopes above 2000m on an array of aspects,

occasionally lowering to 1800m as avalanche

conditions existed throughout the season

with storm snow being the main concern.

Late September was the most significant

advisory, backcountry travel was not advised

as the danger rating trended to HIGH as

deep instabilities existed sensitive to the

weight of a single skier and inclement

weather conditions made safe route finding

challenging for even experienced persons.

This advisory remained for over a week.

Currently alpine winter conditions still exist

in the Mt Ruapehu/Tongariro region and

daily forecasts will continue through October

and into early November where from there

on, intermittent advisories will be entered as

significant hazards arise.

BY DENHAM STEWART

12

+TARANAKI REGION +

THE WEATHERWinter struggled to make a start in Taranaki

this year. We did receive some good snow

falls which you could count on one hand

but this was closely followed by very warm

weather conditions where the freezing level

would go close to the top of the mountain on

many occasions. Starting from July our first

good bit of winter weather happened around

the second week where we received snow

from the south east down to 1000m. This

was followed by a warm settled period with

varying temperatures before the end of the

month brought more snow to low levels.

For the start of August the snow on the

mountain didn’t fair too well with 110mm of

rain recorded at 1400m on one day with more

rain during the week. This weather decimated

the mountain snowpack. This was followed

by cool clear conditions before the next lot

of warm rain on the mountain reduced the

snowline to around 1900m. Towards the end

of August we saw a return to some winter like

conditions with snow falling to low levels.

The start of spring saw a mix of snow and

rain across the mountain until the much

talked about storm that crazed the country,

and brought snow to low levels across the

Taranaki region. Strong south westerly winds

and snow as low as 500m hit the region

during this storm, but unfortunately as the

storm cycle came to an end we saw a rapid

warm up with rain. The freezing level has

climbed to around the top of the mountain

and most of the snow received during this

storm has gone.

THE SNOWPACKWith such an up and down winter the snow

pack had little time to accumulate into any

mass below 1800m. As mentioned in the

weather section we did receive several good

snow falls with 20-30cm above 1400m at

the end of July with moderate south easterly

winds. For most of July the snow pack was

well consolidated with multiple crusts within

the pack. Come August what snow that the

mountain had retained was hammered by

heavy rain across most of the mountain

below 2100m. As conditions cooled following

this rain, the snowpack became very firm.

20cm of snow fell over the last week of

August above 1500m. September saw heavy

snow fall to low levels with strong to gale

force winds. Large pillows of snow formed

on leeward aspects to the south west with

significant weak layers buried within the

wind transported snow. This was quickly

eliminated as the rain came down a few days

after this storm.

AVALANCHESSeveral avalanches have been recorded

near the ski area on the mountain this year.

On both occasions these happened during

the storm cycle with the larger avalanches

happening in the September storm. If

mountain users witness avalanches or debris

please report to the local Mountain Safety

Council or the Ski Area.

CONCLUSIONThe winter of 2010 in Taranaki was one to

forget, with only a handful of operational

days for the local ski area. Any snow that

was received was immediately followed by

rain which destroyed any hope of building

a good base of snow. So conditions haven’t

been great this winter for recreational

activities on the mountain but those that did

venture out kept safe. Looking forward to the

coming weeks of spring; use general care as

conditions will vary on the mountain from

hard in the morning to soft in the afternoon.

Care will be needed around steep unsupported

aspects in the afternoons as heat takes its

toll on these slopes. Thanks to all of those

that send in information and took the time

to read the daily forecasts. Remember to be

safe out there as the mountain will always be

there tomorrow – make sure you are too, wait

till the conditions are right.

BY TODD CATIONS-VELVIN

+NELSON LAKES REGION+

OVERVIEWThis was the second winter that the Nelson

Lakes Region had an Avalanche Advisory

using Avalanche.net. This season has been

disappointing for snow cover in the park with

a large part of the early season with very

minimal coverage. Rainbow is surrounded

by excellent back country touring which is

well know by local users but this season has

seen little ski touring activity with mostly a

small amount of slack country use directly

around Rainbow Ski Area. The New Zealand

Back Country Ski Guide refers to Rainbow

as well as the quality of the terrain around

Angelus Lake for back country touring so

this year’s inactivity is an anomaly caused

by lack of snow cover. DOC has posted the

advisory on a daily basis at the St Arnaud

park headquarters again this winter and

has assisted the forecasting team with an

occasional seat in a helicopter for over flight

and snow pack observations.

The primary source of information is still the

Rainbow Ski Patrols ongoing observations in

the St Arnaud range on the eastern boarder of

the national park. Secondary to that the NIWA

meteorological site on the Mahanga range in

the western side of the park sent twice daily

automated emails to the forecasting team

and access to the web based data was secured

this winter which allows the team to view

real time data with comprehensive weather

information. This season Rainbow Ski Area

has installed a Davis system with most of

the valuable recordings required which was

available real time from a web site. We still

struggle to get avalanche observations from

the western and southern part of the park

due to its remoteness and lack of personnel

in the area during winter.

WEATHER AND SNOWPACK.After approximately 60cm of snow in early

June the weather conditions remained clear

and calm for several weeks. The shallow snow

pack and cold air temperature created a very

weak snow pack similar to further south. The

snow pack had very pronounced facets below

14 CRYSTAL BALL13

a brittle ice crust. This layer would have been

very problematic with significant load and

remained very prominent for some time.

Late June and July have seen long periods

of settled weather interspersed by periods

of disturbed westerly often associated with

high freezing levels. Very little snow fell

during this period. There was not significant

snow fall until mid September by which time

this layer had been strengthen by a number

of rain events and warm air temperature. Mid

and late September has seen a significant

increase in snow cover with the strongest

westerly airflow seen for some time. With

approximately 120cm of new snow falling in

the park associated with very strong winds

from the westerly quarter, the avalanche

danger was at considerable and high for

some time. Density variation was the most

common weakness during this time and one

significant slab avalanche cycle occurred

within the new snow during the storm.

The disturbed westerly has continued but

a significant increase in temperatures and

rain to high levels have produce a significant

loose snow avalanche cycle on the 100926.

This was due to storm snow on eastern

aspects becoming saturated. Warm moist

conditions prevail at the time of writing this

and loose snow activity is anticipated to be

occurring as the month draws to a close.

Back country users will need to be aware that

significant snow exists on eastern aspects

and this may well continue to develop given

the disturbed weather being experience

during this spring so far. Caution will be

required as spring continues due to snow

volumes on these aspects. There has been no

significant weakness noted recently within

the snow but warm temperatures and rain

will decrease snow strength and care will be

required during those times.

AVALANCHE OCCURRENCESOnly two significant avalanche cycles

occurred this winter to date. The first was

wind slab on approximately the 100920 on

eastern aspects due to significant storm

snow volumes, intense wind loading and

precipitation intensity.

The second was a loose snow avalanche cycle

on the 100926 due to a rain event to high

elevation on northern and eastern aspects.

Prior to this the occasional loose snow

avalanche and small wind slabs isolated

to ridge crest occurred but not of any great

significance.

CONCLUDING REMARKS No avalanche involvements have been

reported to the forecasting team from within

the park at the time of this reports writing.

This is due in no small part to the lack of snow

and hence backcountry use in the majority of

the park. It has been reported that a class 3

slab avalanche was initiated remotely outside

Mount Lyford’s ski area boundary in the early

season but this remains unconfirmed. We

still have work to do in the northern region of

the South Island in terms of educating people

about the avalanche phenomena and the use

of Backcountry Avalanche Danger Advisory.

The success of this program continues to

be possible due to the efforts of Rainbow

Ski Areas professional Patrol department

and the Rainbow Management Group as a

whole. Access to the information from the

Ski Areas Davis weather system has assisted

the forecasting team greatly. Thanks again

to NIWA for access to the Mahanga weather

site information and the DOC for helicopter

access to the park.

BY MATT WILKINSON

+ARTHUR’S PASS REGION+

OVERVIEWThe Arthur’s Pass region was off to a slow start

snow wise this season. July and August saw

northwesterly flows from small disorganized

storm cells which brought above average

temperatures, wet weather and high winds

from the north. In September things started

to change to more normal weather patterns

as large Antarctic systems began to come into

our area bringing colder temperatures and

more snow. At press time we are under the

influence of large,well organized Antarctic

low pressure systems which are bringing high

winds from the northwest as the systems

wrap around the island and much snow.

WEATHERWinter came a bit late this year and for July and

most of August any snowstorms that we got

were knocked right back down by rain storms

that followed. July 21st storms brought about

30 cms of snow and on July 27th there was

14

another 35cms. It rained 125 mm on August

1st and 2nd followed by 10 cms of snow on

August 7th. There was 175mm of rain over

August 13th and 14th and 20 cms of snow on

August 18th which caused some widespread

avalanche activity. The end of August saw

about 30 more centimeters of snow. The

first few days of September brought about

40 cms of new snow giving skiers some

hope that things might improve but, those

hopes were washed away when a 200mm

rainstorm on September 5th and 6th brought

snowpack levels back down to the 35 cm

level at 1400m. On September 3rd we had an

earthquake. Then on September 17 it started

snowing in earnest. The small disorganized

storm cells that had been coming in from the

northwest finally gave way to a much larger

and more normal pattern of Antarctic air

pushing up from the south. The result was

that by September 21st we had more than a

meter of new snow and it is still snowing at

the time of this report. Although we did not

have much snowfall near the beginning of the

season we had quite a bit of wind resulting

in the snow, particularly at high levels, being

moved around ,collecting in gulleys and filling

in between the rocks. The big rainstorms and

cooler temperatures that we received washed

away weak layers and helped to stabilize the

snowpack before the big dumps arrived.

SNOWPACKEarly season snowpack below 1600m was

below threshold through the first week in

August. The snowpack above 1600 metres

showed some distinct weaknesses in the

early part of the winter. There were some very

thin friable ice crusts at or near the surface

that did not appear to have much strength.

Underneath this thin crust there was 20 to 30

cms of weakly bonded, unconsolidated snow

that provided little support. To date, the most

significant effect has been the extensive rain

that we have received. Whereas there were

some weaknesses in the snowpack before

the rains and there were some avalanches

caused by the rain, after the rain had stopped

and the snow pack drained and temperatures

cooled, the pack became super stable.

Subsequent snows along with high winds

became well bonded and stable. It remains to

be seen how much more new snow can fall

before things start to slide again. There has

been over a meter of new snow in the last

week and nearly continuous gale force winds

from the northwest. Therefore aspects lee to

the northwest must be loading but so far no

avalanches have been observed on the east

face of Mt. Rolleston when we can see it. We

are well into our second meter of snow since

September 17th and it continues to snow.

Avalanche Danger on the Minga and other

eastern aspects is HIGH.

AVALANCHESDuring July there were some very thin

ice crusts overlaying 20 to 30cms of

unconsolidated snow above 1600 metres.

When 20 cms of new wet snow fell on top of

these layers remarkably they did not collapse.

Instead avalanches occurred on top of the

thin ice crusts (1cm) and did not step down to

the nonsupporting layer. These slides started

as very small fractures, maybe 10 cms deep,

very high up on the slopes and by the time

they reached the bottom of the run outs they

had grown to size 3 and 4. Another

phenomenon that occurred was when heavy

rain washed over bare rocks and compounded

the amount of water received by the

snowpack below, led to deep slab avalanches.

There was the usual new wet snow point

sloughs caused by solar radiation but the

most unusual thing that occurred this winter

was the earthquake on September 4th which

caused cornices to fall on southeast aspects.

No resulting avalanches were recorded from

this event.

CONCLUSIONIt was a stormy winter in Arthur’s Pass both

with rain and a late charge of snow. There was

a tremendous amount of wind and rain that

eventually made for stable snow conditions.

Climbers got to climb some great ice and

stable chutes,and now skiers are getting

some great snow. No one was caught in a

slide and it was, over all, a safe season. Many

thanks to those who contributed observations

and provided data across the region.

BY STAN TENER

+CRAIGEBURN REGION+

OVERVIEWThere’s a saying in New Zealand “Snow in

June- still too soon”. Early falls of snow

in May and June gave way to an extended

period of high and dry in July. Local ski fields

were able to open as planned and decent

backcountry skiing could be found in the

regions upper basins but snow coverings

were thin and surface quality was average.

The odd shot of winter weather kept things

going through to the usual seasons’ end but

skiers were forced to make the most of a thin

and weak snowpack for much of the season.

WEATHEREarly periods of winter weather in May and

June gave way to a dominating series of

anticyclones with cool and mainly settled

conditions persisting for much of July. A

pattern shift in late July and August allowed

for a series of cut-off lows (low pressure

systems unassociated with the jet stream) to

track NW to SE across the South Island. NW

storm portions delivered more wind and rain

than snow but lingering wrap around energy

from the E and SE delivered significant

falls of snow to low elevations on several

occasions. A couple “more intense” westerly

depressions late August and early September

delivered severe winds and heavier falls of

rain and snow to the range (85mm of rain to

the top on 13 and 14 August, 40cm or so of

snow over the last week of August and 65mm

rainfall with 30-40cm of snow during the first

2 weeks of September). A significant pattern

change mid to late September, (again a result

of a shift in the tracking of the Southern

Hemisphere’s ridges of high pressure)

allowed a series of deep troughs to deliver an

extended period of cold, severe W ¼ winds,

and by far, the heaviest snowfalls of the

season.

SNOWPACKA rain crust remnant from May’s deposits

was eventually buried by snowfall on 22 June.

After a significant period of cold weather,

the crust/ low-density snow combination

developed into a weak faceted layer, which

would be the dominant snowpack character

in July and August. This faceted layer was

especially tricky to track, being fairly wide

spread across the high shady aspects, but as

determined by the nature of the storm on 22

16 CRYSTAL BALL15

June (where S ¼ winds scoured most snow

near ridgeline) it was usually only found low

in start zones and at the mid slope level)-

a recipe for disaster if stability was based

solely on observations taken from high in

the start zone. The 22 June faceted layer was

eventually washed clean by rain on 13 and

14 August. The new (18 August) crust / low-

density snow combo weakened quickly on

upper elevation slopes of the S ¼- becoming

the second significant persistent layer of

the season. On 24 August, a layer of 4-8mm

surface hoar became buried by falls of snow

and graupel (mainly found on upper elevation

slopes of the E ¼). This too would become a

significant persistent layer in coming weeks.

A “rain to the top” event on 6- 9 September,

and the eventual refreeze of the snows surface

on 14 September would isolate any remaining

weak, loose, or saturated snow existing at

depth. From then, the snow would remain a

more typical, well-bonded springtime pack,

with instability being related more to storm

snow inconsistencies and the freeze/ thaw

cycle of the snow’s upper layers.

AVALANCHE OCCURANCESJunes’ faceted layer was responsible for a

few natural occurrences (to size 2) from

mid elevation S ¼ zones on 1 August. In

the weeks that followed, backcountry skiers

and boarders stayed mainly out of harms

way but the snow pack’s dangerous nature

was displayed by a few close calls and

multiple reports of large slope settlements

(whoomphing) associated with the 22 June

layer. Numerous large (to size 3) natural

occurrences were observed out of mid and

upper elevation S ¼ zones after the 13 August

rain event with some large debris observed

to valley floor. The 18 August faceted layer

and the 24 August surface hoar layer were

first seen to react to the storm loadings of

2 September. Occurrences to size 3 were

observed to have run to valley floor (from

upper elevation E facing zones). During the

fine weather that followed the 2- 3 September

storm, it was believed that while natural

avalanching was not as likely- there remained

a real danger for large triggered avalanches.

The seismic jolt in the early morning hours

of 4 September verified the tender nature

of the snowpack. In the Craigieburn and

Torlesse Ranges, numerous occurrences

to size 3, mainly from E and SE zones ran

to over a metre in depth and hundreds of

metres wide on the buried persistent layers

of August. Very large occurrences were also

observed in the neighbouring Grey Range-

slabs to over 1000m wide involving entire

basins. A significant cycle of triggered wet

slabs occurred during the 6 September rain

event and subsequent days of above zero

temperatures. Controlled occurrences to size

2.5 were reported mostly out of mid elevation

E ¼ zones, with significant occurrences

reported from the W ¼ as well.

TRAVEL ADVISORYIn spring, weather factors seem to have

an amplified effect on stability. Snow and

blowing snow can be fierce and temperature

spikes can quickly loosen previously strong

interfaces. During unsettled weather, storm

snow and wind slab is usually the main

concern- watch for storm weaknesses to be

especially sensitive to the lee of ridgeline and

features of the dominant wind direction.

If weather becomes intense, you’ll need to

think about avoiding avalanche terrain all

together. When the sun comes out, turn your

focus to radiation related instability. Look

for signs of slopes preparing for a shedding

of their winter coat (snowballing, lubricated

feel underfoot) – that’s your que to retreat to

lower angle terrain.

CONCLUDING REMARKSIn New Zealand, its not often we’re

exposed to such a lengthy period of old

snow instability as was experienced this

season. Snow coverings were for much of

the season thin and inconsistent. On several

occasions, harsh weather had its way with

the snow cover- leaving a heavily wind and

temperature sculpted surface. There was

however plenty of opportunity for a quality

backcountry experience. Low angle, shady

terrain offered good powder stashes and

August’s cold southerly storms deposited

above average and generally well bonded

coverings of snow on the ranges western

faces. A season like this offers a good

environment for learning about snow and an

opportunity to practice using terrain to your

advantage. Learning the subtleties of terrain,

and its effect on stability will put the odds

in your favor and allow you to travel across

a wider variety slopes with greater safety. A

quick thank you is in order to the mountain

community of the Craigieburns. Much obliged

to the many teams and individuals who

contributed snow, weather, and avalanche

information, vital to the cause. Information

from ski area snow safety teams, ski guides,

avalanche and mountain educators and of

course recreational parties was irreplaceable.

Go Safely.

BY DAMIAN JACKSON

16

+MT HUTT/ARROWSMITHS REGION+

Overall the 2010 season was dominated

by easterly winds for the early part of the

season and strong NW winds for the latter.

The easterly produced a lot of cloud, snow

and rain for the Mt Hutt part of the region

with less snow near the divide. The temps

were typically a lot warmer than usual with

the freezing level around the 1700m mark

causing a lot of storms to rain at Mt Hutt

before the freezing level dropped during the

storm. Mt Hutt was dominated by southerly

weather systems for the first 4 months of the

season. Significant snowfalls came late in

the months of May, June, and July all from the

southwest to the southeast. The low easterly

cloud persisted above the Canterbury plains

so on a number of days you could head up out

of the cloud to Mt Hutt or The Arrowsmiths

for a blue sky, calm day of great skiing or

riding. The largest snowfall for Mt Hutt

came on Aug 7-8th where in a 30 hr period

Mt Hutt received over 1m of new snow from

a classic SE storm. The rime crusts of most

significance were buried on July 20th, July

31st, and Aug 13th with avalanche activity

occurring on all crust layers in the Arrowsmith

region. The cloud also helped produce a lot of

surface hoar, with a number of observations

made with concern about the new snowfall

on top. There were regular observations

of 2cm surface hoar but most layers were

broken down by the rain at the start of the

following storm. The most significant surface

hoar layer was buried on Aug 17th and this

played a part in the Sept 4th earthquake

event avalanche cycle. Late Sept and early

Oct saw the start of the spring westerly cycle

that seemed to last forever. Strong winds and

heavy precipitation brought an estimated 5+

metres of snow over 2 weeks to areas close

to the divide at higher elevations. Winds

were gale to severe gale force throughout the

whole period with the odd welcome day with

less wind. The snowpack was challenging this

season. As mentioned above Mt Hutt often

received rain as part of the storm cycle and

would finish with rime leaving hard surfaces.

It also aided facet growth and caused a

number of avalanche events both around Mt

Hutt and in The Arrowsmiths to occur days

after the storm.

An overall shallow snowpack in The

Arrowsmiths caused facet growth that

remained a player late into the season due to

the lack of heavy precipitation from NW

storms. It wasn’t until the mid Sept warming

trend and following the freeze that we felt

the deeper instabilities were finally non

reactive. It was a season of lots of digging

for facet layers and hunting for the surface

hoar that was observed before the snowfalls

but often not found afterwards, the result

of storms starting warm and destroying the

surface hoar layers of concern.

ARROWSMITHIn The Arrowsmith region the usual storm

avalanche cycles occurred with some paths

joining on facets/rime crust to size 3.5 in

events never witnessed before.

The most relevant skier triggered event

occurred on Sept 11th with an avalanche

occurring on a north facing run - a hard 2cm

crust failed into moist facets. No one was

injured but this was a timely reminder to

stay patient until the whole snowpack had

frozen and not rely on bridging layers. Mt

Hutt had an explosives triggered size 2.5

avalanche which buried the road on July 24th.

This was another example of the significance

of the rime crusts as the avalanche stepped

down onto the lower buried crusts. The

South Face was triggered post control on

Aug 10th, which was an unusual event as it

occurred in a place never witnessed before -

on lower angle terrain compared to where the

avalanche control work had been undertaken.

This prompted 2 Land SAR avalanche search

dogs to be deployed due to conflicting

information from witnesses , the debris

was cleared quickly and a car park count

confirmed no one was missing. The size 7.2

earthquake on Sept 4th caused a widespread

avalanche cycle throughout the whole region.

Most observations were on SE aspects and

suspected on the Aug 17th surface hoar

layer. Another part of the cycle occurred

below 1700m on north aspects. This made

for an interesting time looking around at how

significant the earthquake was. Very little

of the season seemed to be low danger, and

care was required when travelling into the

backcountry. Backcountry users seemed to

be up on last year, with no incidents possibly

indicating educated care in timing and use of

terrain by these users. This is positive to see

and may it continue into next season.

BY JAMIE ROBERTSON

18 CRYSTAL BALL17

+AORAKI / MT COOK REGION+

The beginning of the 2010 season followed

a similar pattern to last year, early snowfall,

shallow snowpack followed by fine cold

weather promoting faceting and surface

hoar development. The fine spell broke

on the 20th July and the subsequent few

days of poor stability saw the first of

many avalanches running on the 19th July

facets. Each subsequent storm resulted in

avalanching both within storm snow and on

the 19 July layer. Notable avalanche cycles

to size 3 occurred on the 26th July - 1 & 2nd

August and the 13th August during periods

of intense precipitation. Many avalanches

were observed to run to valley floor during

these cycles but the extent of debris was

not as great as last year. Stability rated

good for the first time in over a month on

23rd August by which time it was felt that,

even though the July 19th layer could still be

found well preserved beneath a strong crust

on undisturbed low angle slopes, it had been

destroyed on all possible avalanche terrain.

Storms at the end of August and early

September were generally weaker than mid

winter events, freezing levels occasionally

crept up with some rain events above 2000m.

A couple of reasonable avalanche cycles

happened on the 26th - 28th August and 6th

September with slides up to 2.5 generally

failing to overrun the extent of previous

debris. Interestingly the 26th August slides

had many size 2 avalanches initiating around

the 1900m mark, the same altitude where the

previous snowfall/ old surface had tapered

down to “dust on a crust” By the 28th with a

bit more snow and wind the size and altitude

went up a bit and pretty much the whole S

face of Hochstetter Dome fell off.

16th September saw a return to winter

conditions with the onset of a very large low-

pressure system bringing strong Westerly

winds and snowfall to low levels. Precipitation

was not especially intense during this period

with the maximum 24 hour rainfall only

43mm but the prolonged cold and windy

nature of the storm has led to a huge amount

of snow transport and some good size 3

avalanches observed to have run to valley

floor in the Hooker. It is presumed that other

widespread avalanching occurred but bad

weather meant limited obs and those crown

walls that could be seen were soon covered by

drifting snow. An instructive demonstration

of the effects of cross loading was seen in the

timing of two of the Hooker valley events. On

the 20th September after 4 days of W to NW

winds and around 1m of snow on the divide

the Hayter Stm. Avalanche path ran right

down to the Hooker Lake. The neighbouring

Stocking Stm path, which threatens the

approach to Sefton bivvy, hung in till the next

day when a wind shift to the SW delivered

titanic amounts of snow from the up wind

fetch area of the Huddleston gl overloaded

the slope and brought down another solid

size 3 slide. It’s not the first time this has

been seen and is worth bearing in mind for

those chasing the tail end of a storm in there

to climb Footstool.

At the time of writing we are 10 days into

the howling westerly epoch that began on

the 16th. Over 3m of snow has fallen at the

head of the Tasman so far and it looks like

the sunscreen will stay in the tube for a while

yet. Despite this the future looks good for

spring touring in the region, great snow cover

to low elevations, well bridged crevasses,

and a snowpack that should settle down

reasonably well to the usual spring freeze -

thaw pattern if ever these westerlies run out

of steam.

AVALANCHE INVOLVEMENTS THIS WINTER:On the 3rd August a guide took a ride of

about 100m on a raft of slab when a stiff

pocket of ridgeline windslab pulled out while

traversing to lower angled terrain on the

Ridge gl. He remained on the surface. On the

9th August two snowboarders were hit from

above by a size 2 slab triggered remotely

by a photographer traversing unexpectedly

above them. They were swept 200m down

steep but open terrain and remained on the

surface. This was the only human triggered

event on the July 19th layer, which at the time

and place of the slide was capped by a strong

10cm crust with 40cms loose dry powder on

top. The 50m wide slab was the last remaining

pocket in an area that had otherwise been

well stirred by previous avalanching. On the

14th September a ski tourer accidentally

triggered a size 1 slab on the cornice wall (east

aspect) following a small dump with some

westerly windloading. Finally, a big thank

you to Niwa and Meridian for giving access

to their remote weather stations. The data

has provided useful insight into the effects

of storms on different ranges in the Mt

Cook area and has been especially valuable

during the long periods this winter when bad

weather has prevented direct observations in

the backcountry.

BY TREV STREAT

18

+WANAKA REGION+

OVERVIEWAll things considered, the 2010 winter was

pretty uneventful in the Wanaka region.

Limited amounts of snow arrived at least,

during the early and middle pasts of the

season and significant storm activity was

reasonably unusual. Periods of High danger

were infrequent and brief. Most important

was the fact that there were no reports of

backcountry incidents involving full burial or

serious injury – a very pleasing outcome.

WEATHERThe 2010 season in the Wanaka region was

characterised by long periods with little or

no precipitation and generally light winds.

This pattern persisted through until the end

of August, when it could be said that winter

finally arrived.

MAYThe weather in May produced few surprises.

Temperatures were mild, reaching between

6 and 8 degrees during the day on a regular

basis and seldom falling below minus 1 at

night. Winds were light from the North or

West early in the month while a South East

flow again, with light winds, developed in

the final week of May. This South East flow

produced a small quantity of snow (10cm

over three days right at the end of the month

– 1250m). A layer of inversion cloud hovering

between 800 and 1000m was present on

most days.

JUNEA Southerly flow prevailed during the first

week of June with light South or South West

winds and no precipitation to speak of. On

the 8th of June 30cm of snow was recorded

at 1250m but winds remained light and

predominately from the Southerly quarter,

The 19th of June was marked by the arrival

of a warm, moisture laden North West

system that produced a significant quantity

of rainfall (50-60mm plus, in the East of the

region) to at least 2000m. A substantial rain

crust formed as a result of this event and,

it was to become a problem for some time.

The last week of June saw a return to cold,

clear conditions and light winds mainly from

the South East. This, in turn, lead to the

widespread formation of surface hoar, mid

pack faceting and the growth of depth hoar

at ground in many places.

JULYIn early July, we witnessed a long spell of

settled weather with virtually no precipitation

and light winds principally from the Southerly

quarter. These conditions, when combined

with the shallow snow pack produced

rampant faceting and further depth hoar

development in many areas. This situation

persisted until July 20th when a weak NW

storm delivered a small amount of new

snow (10-20cm at 1250m). Small snowfalls

continued during the last week of July as the

result of weather systems from the Southerly

quarter. Winds remained light.

AUGUSTThe first week of August produced very small

amounts of precipitation and light winds

from the Northerly quarter. On August 8th,

a South East flow delivered 15-20cm of snow

(1250m), which was accompanied by light

winds. Mid August saw a return to largely

settled weather with very limited amounts

of precipitation and light variable winds.

The snow pack remained in essentially early

season condition during this period, that

is to say, shallow and weak in most places.

Large settlements and mainly small remote

releases were commonplace. However,

widespread, large-scale natural activity was

rare due mainly to the fact that new snow

loading was insufficient in volume and weight

to trigger on the buried weaknesses. Towards

the end of August a disturbed Westerly flow

began to assert itself with increased amounts

of precipitation and more frequent bouts of

strong wind.

SEPTEMBERIn early September, it became apparent that

winter had finally arrived with a pronounced

increase in both precipitation and wind. On

the 17th, 30cm of snow fell at 1750m as the

result of a North West storm. This pattern

continued over the next couple of weeks

with frequent snowfalls and gale to severe

gale winds from the Westerly quarter. This

unsettled Westerly pattern looks likely to

continue into October.

AVALANCHE OCCURRENCES AND INVOLVEMENTSFortunately, backcountry avalanches

involving humans were quite rare this season.

There were several reports of human triggered

remote releases which must be classified

as near misses but according to the records,

no backcountry users were fully buried

or seriously injured. The rain crust which

formed June 19th and subsequently facetted,

constituted the principle weakness in the

pack during the first half of the season. In

mid to late August, the cold, clear conditions

produced widespread areas of surface hoar

which then became buried. Numerous size

1 and 2 slides, accidental and remote, were

recorded in the latter part of August and

these were believed to have failed on buried

surface hoar. No direct involvements (burials

or partial burials) were reported during this

period. Large settlements were reported

throughout the winter but this is not

surprising given the shallow, weak nature of

the pack during much of the season.

SPRING TOURINGAs spring takes hold, it is easy to become

somewhat complacent about the potential

for avalanche danger. Spring is renowned

20 CRYSTAL BALL

19

than 10 CM’s. In fact this region has not

received a single snowfall above 20 cms in

over 3 years, what has happened to the knee

deep falls of the 1990’s, global warming

?) and without much wind. This point is

important, the snow was light and unaffected

by wind, which we all know is responsible

for making slab conditions. Without a

slab there was virtually no tension in the

snow, this was the single most contributing

factor to a decreased avalanche cycle this

season. Slowly the snowpack depth grew,

eliminating the strong temperature gradient

that plagued the early season snowpack.

The early August rain event, complete with

warm temps, added a significant amount of

free water to the pack. After a week of above

average temperatures, winter returned. The

pack locked up solid, people could hit some of

the steep terrain that had tempted them all

season with confidence. Mid winter produced

some superb backcountry snow conditions

without the fear of large destructive

avalanches that we experienced the previous

season. The late August early September

spring skiing was superb, again consistent

with a well consolidated snowpack. This

season (as with ‘09) we have experienced a

late burst of winter, this late winter snow

has been well publicised this year because of

its duration and intensity. The initial storm

was classified as the largest on the planet at

one stage and as many Southland farmers

will no doubt recall as one of the deadliest,

thousands of young lambs dying throughout

the storm. For this region it brought severe

gales (some gusts over 160 kph) from the

North West, West and South West, snow to

around 300m, over 1.5 m of snow in total for

over 8 days, some storm cycle.

AVALANCHESThere were 9 people caught in avalanches

in this region resulting in 4 part/full burials,

there are a couple of interesting notes on

these burials. Firstly 3 of the burials were

backcountry users that had no form of

avalanches rescue (no shovels, probes or

transceivers!) and all were snowboarders.

The 4th burial (also snowboarder) was the

OVERVIEWIt is typical to draw analogies between

seasons and it is bizarre how similar to the

‘09 season this season has been, albeit

without the fatalities (although there was

one we shall discuss later). It was the events

of mid season that saw this season take a

different path and avoid the major avalanche

cycle that the ‘09 season was remembered

for. Lets disseminate the season around this

region.

WEATHEREarly season snowfalls were consistent

allowing for early openings of local ski-fields

but much like last year, this was followed

by an extended period of settled, calm

weather, lasting nearly six weeks without any

significant snow. When the snow did start

arriving it did so in small quantities (10 to

20 CM’s max) again without much wind, this

was the main difference between the two

seasons. There was a similar period where an

Easterly airflow dominated the picture, lots

of low cloud and riming of the snowpack. At

the start of August there was a significant

rain event (also similar to last season), the

difference here was with the rain came a

rise in temperature. The warm rain followed

by a return to colder temperatures and more

snow had the snowpack looking strong.

From September a typical spring followed

producing great corn snow conditions. To

continue the strange paralleling we have

had the late return to superb winter snow,

making October conditions some of the best

of the season.

SNOWPACKThe early season dry spell with very cold

temperatures weakened the pack, fears

of another major avalanche cycle became

very real. Then came the familiar pattern

of Easterlies with its associated low cloud,

cold temps and rimed snow. When the snow

began arriving it was in small amounts (less

as a great time to go touring but also for

unpredictable, turbulent weather. Winter

type storms producing slab avalanche

conditions are possible at any time. If in

doubt, let the snow settle out for a day or

so and then select appropriate terrain. With

the increasing temperatures and high solar

radiation, be wary of crossing sun-affected

slopes, which could release unexpectedly as

very large (climax) wet slides. Take careful

note of warning signs that indicate that

slopes are warming and potentially becoming

less stable. These can include very soft deep

snow; glide cracks and rapidly increasing

temperatures. Stay away from terrain traps

such as steep, narrow gullies, confined

drainages and run out zones, should you feel

that things are deteriorating.

Thankyou to the information providers

Without the support of local heli-ski

companies, guiding operations, ski patrols

and keen backcountry skiers and riders and

their willingness to exchange information

and observations, it would be extremely

difficult to compile timely and useful reports.

Thanks are due to all these people for their

invaluable information during the winter.

BY SIMON HOWELLS

+QUEENSTOWN REGION+

20

first known case of an avalanche air bag

being deployed in an actual avalanche in NZ,

although completely buried the airbag was

noticed by a sweep from a helicopter, and a

successful and relieved companion rescue

was completed. A quick mention about

the only fatality reported in this region.

While touring in the Remarkable’s range, a

set of antlers (12 pointer) appeared out of

avalanche debris, on closer inspection a large

red stag was uncovered. It was obvious the

animal had perished in a recent avalanche, an

interesting event. Has anyone come across

something like this before?

CONCLUDING REMARKSBefore I conclude, I would like to send out

a big thanks to the snow safety crew at the

Remarkables, these guys take their work very

seriously, the level of reporting, snowpack

Creek Grange ACE Ltd Avalanche control supplies

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Photo: ACE Round firing from a Nitro Express at Mt Hutt

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Training available for:-

Approved Handler Licence

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[all training overseen by Qualified Assessors]

and avalanche obs to the info X was, and

continues to be, at the highest level of any

provider in the country. It has made my job

a lot easier, thanks team. I suppose the

highlight of the season would have to be

the fact we had no fatalities, unfortunately

the low would be, this was mainly due to

luck. For people to be still heading into the

backcountry totally unaware that they are

in avalanche terrain, to not carry one piece

of rescue equipment, in this day and age is

almost unbelievable. Albeit but a twist of

fate there could have easily been several

fatalities this season. Our work continues, to

educate the uninformed, to get the message

out there. If you are in a situation were you

see people heading backcountry ill prepared

then speak up, if you are one of the lucky

people to escape this season then educate

yourself. The MSC avalanche awareness

campaign is highly visible, the new plans

in place will make it even more accessible.

Watch this space as plans are in motion to

take avalanche awareness to an all new level

next season, see you then.

BY CHRIS COCHRANE

22 CRYSTAL BALL

17

Blake Harrington and David Trippet, P iedra Blancas G lacier, Argentine Patagonia.

MIKEY SCHAEFER

B l a c kD i amondEqu ipmen t . c om

Travelling in The backcounTry?

22

WHY USE DOGS?

Sense of Smell – dogs have 220 million scent receptors

(we have 5 million)

Speed – they are FAST.

Survival statistics tell us that 90% of avalanche victims are alive at the

fifteen minute mark. After 35 minutes the survival rate is at 30% and

quickly drops after that. A well trained avalanche dog is equivalent to

approximately 20-foot searchers and can search the same area in an

eighth of the time. One dog can search one hectare in approximately

30 minutes - it takes 20 foot searchers 4 hours to search the same

area with probes (covering about 2.5% of the total area that the dog

could cover).

There are currently 14 operational teams in New Zealand. All teams

are assessed annually by Land SAR Civilian Assessors and the NZ

Police Dog Section. This support gives us credibility with the police

as well as an unbiased and professional viewpoint. All dogs must be

deemed to be at an operational level to be accepted on the national

assessment course and it generally takes a minimum of 2 years to

train a dog to that level. Our standards are high – dogs are required

to find 2 human and one article find in a 100m x 100m site in under

20 mins. In addition, there are minimum skill criteria required for our

handlers although of our 14 teams, 9 handlers are highly skilled in

snow safety and hold senior positions as patrollers and guides.

A list of current operational dogs can be found on our official website

www.searchdogs.co.nz and is updated after every assessment.

It is important that you know the operational dogs in your area so take

the time to check out the site. Land SAR Avalanche Search Dogs are

the only officially recognised resource.

DEPLOYING AN AVALANCHE SEARCH DOG:

Search dog mobilisation should be directed through the New Zealand

Police, either local or by the 111 system - if however the dogs and

handlers are deployed by other means, then the NZ Police should be

notified as soon as possible thereafter.

It is essential to speed the arrival of search dogs at the accident site

and air transport must be a priority for the dogs and handlers. If at

all possible a dog and handler team should be included in the first

response party as this is the best chance of survival for a victim who

is not wearing a transceiver.When dogs are to be used at an incident

site it should be attempted to locate landing and equipment sites

downwind from the areas to be searched, this will prevent unwanted

odours drifting across the search areas. Some dogs are trained to

search in pairs and amongst personnel already on the debris site, but

you should be aware that a dog handler may require that personnel

leave the debris field or that equipment sites need to be shifted to

allow the dog the best chance of a swift find.

DOGS MUST BE SUMMONED EARLY, DOGS SHOULD BE CALLED

WHILE THERE IS STILL A CHANCE OF FINDING THE VICTIM OR

VICTIMS ALIVE - NOT AFTER ALL ELSE HAS FAILED!

When search dogs are deployed, ensure that further operational

dogs and their handlers are put in a state of readiness in case further

resources are required. Don’t forget, dogs can work equally well in the

dark.

BY KARYN HEALD ROBERTSON

NATIONAL AVALANCHE COORDINATOR

LAND SAR SEARCH DOGS

+AVALANCHE SEARCH DOGS+

While Avalanche Search Dogs have been used in New Zealand for around 20 years, only recently has the national group become

part of Land SAR as one of their specialist groups. This structure has allowed Search Dogs, both avalanche and wilderness in New

Zealand to become a strong, credible and cohesive group.

Blake Harrington and David Trippet, P iedra Blancas G lacier, Argentine Patagonia.

MIKEY SCHAEFER

B l a c kD i amondEqu ipmen t . c om

Travelling in The backcounTry?

24 CRYSTAL BALL

19

20

26 CRYSTAL BALL

21

+EARTHQUAKES AND AVALANCHES+

I’LL HAVE MINE SHAKEN NOT LOADED: EARTHQUAKE INDUCED

AVALANCHING IN CANTERBURY, NEW ZEALAND

A magnitude 7.1 earthquake occurred at 4:35 am (New Zealand

Time) on 4 September 2010. With an epicentre just 40 km west of

Christchurch city (43.55°S, 172.18°E) and a focal depth of only 10km

(Figure 1), the earthquake was widely felt through the entire South

Island and the lower half of the North Island of New Zealand. Within

the Canterbury region shaking intensities of 6 to 7 were widely felt,

with a maximum shaking intensity 9 on the New Zealand Modified

Mercalli Intensity Scale (Figure 2). This earthquake is the most

damaging earthquake in New Zealand since the 1931 Hawke’s Bay

earthquake, but there was fortunately no loss of life despite the ==

While much of the urban areas in Canterbury suffered damage

to buildings, liquefaction, broken water and sewerage mains and

disruption to power supplies, it is the impact on the alpine areas

and the snowpack in particular that the remainder of this article will

consider. It has long been known that avalanches can be induced by

large seismic triggers with the May 1970 M7.8 in Peru and the March

1964 M9.2 in Alaska just a couple of the more notable events (See

Podolskiy et al., 2010 for a good review). With Canterbury in the

middle of the Southern Hemisphere winter it was therefore not

surprising to hear that this M7.1 had caused avalanche activity.

Earthquake location map shows the earthquake’s location (star) and the sur-rounding region (Source: GeoNet, 2010)

EARTHQUAKE DATA

The earthquake was widely felt through the entire South Island and

the lower half of the North Island of New Zealand with maximum felt

intensities of MM9. The observed shaking intensity was documented

using the Modified Mercalli (MM) scale. This is a scale used in

New Zealand and has a twelve step ranking (opposed to 10), with 1

representing the weakest of shaking through to 12 representing almost

complete destruction.25

22

Figure 3: Earthquake damage in central Christchurch (Source: C. Cross, 2010).

Figure 2: Isoseismal map shows contours, derived from a model, of equal MM

shaking intensity for the earthquake (Source: GeoNet, 2010).

26

The motion of the ground was also recorded by a series of instruments

that document the movement in terms of ground displacement,

velocity and acceleration. These instruments are located throughout

Canterbury (Figure 1), but we will look at the sites nearest the main

alpine regions namely; Arthur’s Pass, Castle Hill Village (inland from

Springfield), Oxford and finally Christchurch.

The Peak Ground Acceleration (PGA) which was measured at each

of the recoding stations, is measured in units of percent-g (%g),

where g is the acceleration due to the force of gravity (i.e. 9.8 m/

s2). Values of 8%g to almost 30%g were recorded at Arthurs Pass to

Christchurch (Table 1). In studies of building damage a PGA value of

20%g is often used to define the lower damage limit, but recent work

also shows substantial damage can occur to buildings at lower PGA

values of 10-20%g (e.g. Lee et al., 2003).The pattern of PGA can be

quite complicated at smaller scales, showing variability over a few

kilometres. This can be mostly explained by the differing soil types

and topography near the stations that can significantly change the

characteristics of the seismic waves. This small scale variability will

influence how PGA is experienced in the mountains.

The Peak Ground Velocity (PGV) was also measured at each of the

recoding stations, measured in units of centimetres per second (cm/s).

28 CRYSTAL BALL27

Values of about 4cm/s to over 30cm/s were recorded at Arthurs Pass

to Christchurch (Table 1). In studies of building damage there is a

strong relation with increasing PGV, with considerable damage when

the PGV exceeds 30cm/s (Lee et al., 2003). Both PGA and PGV give

a good correlation with reported shaking for earthquakes larger than

magnitude 5 and above (GeoNet., 2010).

LOCATION MMSHAKING INSTRUMENTS

PGA PGV

METHVEN

ARTHURS PASS

CASTLE H=ILL VILLAGE

LAKE COLERIDGE

OXFORD

CHRISTCHURCH

4-7

4

5

5-6

4-7

4-8

-

7.98%

11.44%

-

15.47%

29.70%

27.76%

-

4.08 CM/S

10.52 CM/S

-

9.88 CM/S

14.82 CM/S*

32.13 CM/S#

TABLE 1: EARTHQUAKE RECORDERS (SEE FIGURE 1 FOR LOCATIONS) (SOURCE: GEONET, 2010).

*Christchurch Aero Club #Papanui High School (both locations within Christchurch)

region a cycle of natural avalanche activity was anticipated The

forecasters had noted a surface hoar layer that might have been buried

intact on certain aspects, but the main concern was the new snow

and the wind loading, and only the deeper buried layers on particular

aspects. Explosive control and ski cutting in the Craigieburn Range on

the 3rd had generally resulted in very limited activity on eastern half

slopes. Reported snow stability tests included a CTM14 RP down 5cm

within low density storm snow. The buried facets and surface hour

(where present) had not been reported to show any sign of activity but

was still of some concern.

Despite this new snow and strong wind loading, snowpack stability

assessments in these regions at elevations from 1500 to 2000m had

generally improved from fair-to-poor on the 2nd, to good-to-fair on

the 3rd. This was mainly because the bonding of the new storm snow

was considered to be relatively strong and the slabs had been mostly

unresponsive in testing. The weaknesses deeper in the snowpack,

such as the lower faceted layer, the crust, and the buried surface

hoar were still a concern on a few aspects. While this layer had been

unresponsive so far, the forecasters knew that the surface hoar layer

(where buried) and faceted layer were both 5 out of 5 scores on the

lemon count for snow structure factors (McCammon and Schweizer,

2002). A snowprofile taken on the 30th of August (four days before

the earthquake) shows the facets, crust and surface hoar, but the new

THE EARTHQUAKE WAS WIDELY FELT THROUGH THE ENTIRE SOUTH ISLAND AND THE LOWER HALF OF THE NORTH ISLAND OF NEW ZEALAND WITH MAXIMUM FELT INTENSITIES OF MM9.

SNOW STABILITY PRIOR TO THE EARTHQUAKE:

In New Zealand the Mountain Safety Council (MSC) are responsible for

daily public avalanche advisories for the key alpine regions (see: www.

avalanche.net.nz). The two main regions impacted by this earthquake

were the Craigieburn Range and Mt Hutt / Arrowsmiths Region. The

forecasts for these are produced by assimilating data from a number

of contributors and sources. The Back Country Avalanche Advisory

(BAA) on the 3rd of September for the Craigieburn Range and for Mt

Hutt/Arrowsmiths region were reporting a considerable danger rating,

according to the 5 step avalanche danger scale.

In the Craigieburn Range the forecaster noted that the snow is strong

at depth on the northern half but remains weak on slopes facing SW-

E with a host of persistent type weaknesses (surface hoar, facets)

having been buried by the past weeks accumulations (50cm or so with

thicker wind deposits). They noted that the slopes with the persistent

weak layer (SW-E) “…remain tender in areas and lack only a trigger.”

(MSC, 2010).

In general, in the days preceding the 4th of September, both of these

regions were experiencing new snow and strong westerly winds.

Reports of slab development on easterly facing slopes above 1600m of

around 50 -100cm were not uncommon. In the Mt Hutt / Arrowsmiths

28

(and subsequent) wind loading is noted as the primary concern (Figure

4). Further additional new snow load was added to this snow pack in

the subsequent four days.

Figure 4: Snowprofile in A Basin at Mt Cheeseman Skifield, Craigieburn Range

(Source: D. Jackson, 2010).

By the end of the 3rd of September most locations were reporting

the arrival of another westerly system, with new snowfall and strong

winds from the North West to West. In the Mt Hutt region soft

slab development with at least 40cm HST on sheltered slopes was

reported by late afternoon of the 3rd. Data from a remote climate

station in the Mt Hutt / Arrowsmiths region indicated that snow and

wind continued throughout the night and that a substantial amount

of new snow and loading would have occurred on the slopes lee to the

western half. The lee slopes (South to East) were now primed and only

lacked a trigger.

AVALANCHES REPORTED:

In the Mount Hutt / Arrowsmiths region multiple slab avalanches

from size D1 to D3 released on slopes above 1500m. These avalanches

were mainly reported on slopes of the eastern half, but were reported

to have occurred on all almost all aspects. The avalanches in the

Mt Hutt region had particularly wide and jagged fractures, with one

observing noting that they had propagated “differently” to that which

was expected for these start zones.

Methven Heliski reported that they “observed a significant natural

cycle in the Palmer Range that was caused by the earthquake. Most

slides were in the 2000-1800m [elevation] range, mostly size 2, and

all on S/SE aspects. [The] Weak layers were the facet and surface hoar

combination buried by 40cm HST on 3008 [30th August] and drifted

to 140cm crown thickness in some areas. [We] Observed no natural

activity on solar aspects. [We] Skied adjacent to slide paths and found

good stability thanks to earthquake” (Figure 5).

The surface hoar was thought to be the main sliding layer and this

had grown out of a hard crust and was considered to be quite resilient.

The southern and southeastern aspects were the locations where the

surface hoar was not destroyed by wind or solar radiation and was

believed to be buried intact. In the Palmer Range it was estimated

that around 95% of the avalanches observed were on the south and

southeastern aspects (Boekholt pers comm., 2010).

Figure 5: Avalanches on a south east aspect in the Palmer Range (Source: L.

Adams, Methven HeliSki, 2010).

In the Craigieburn Range multiple slab avalanches from size D2

to D3 released on slopes above 1800m. These were all reported on

southern and southeastern aspects and were thought to have either

slid on the buried surface hoar layer (100824) or in the facets and

rain crust layer of 18th August (100818). They were generally over

1m deep and 200 to 500m wide (Figure 6). Numerous similar “Ne”

(Natural trigger, Earthquake) occurrences were also observed across

the wider Craigieburn, Torlesse, Grey and Black Ranges (Jackson pers

comm., 2010). In terms of overall scale, the maximum distance from

the epicentre to a confirmed avalanche caused by the earthquake was

approximately 100 km, but unreported avalanche events might have

occurred further away.

Figure 6: Looking south west along the Craigieburn Range to Mt Cheeseman,

with an example of one of the earthquake induced slab avalanche (size D3, SE

Aspect, 1910m) shown in the middle ground (Source: D. Jackson, 2010)

30 CRYSTAL BALL

In addition to the reported avalanche events, large cracks to the full

depth of the snowpack were observed in the Mt Hutt range. These

cracks had the general appearance of glide cracks and extended over

30 meters on south-west and southerly faces. These cracks were

generally in the 1800-2000m elevation range but were also observed

at lower altitudes. Similar cracks were noted at Mt Dobson ski area,

approximately 100km away. Unfortunately, new snow covered these

cracks shortly after the earthquake and monitoring of them was not

possible. Now with the spring melt these cracks have re-emerged and

the Mt Hutt ski patrol are watching them with great interest. While

the cracks were initially observed on slopes with an angle of greater

than 30 degrees, they are now appearing on much flatter terrain

(Figure 7). The Mt Hutt Ski patrol has suggested that they may have

been caused when the shingle bed surface was pulled away from the

snowpack during the earthquake and the unsupported snowpack is

now slumping and cracking. We think that it is likely that these full

depth cracks are not isolated to just this area. However, neighbouring

ski areas (such as those in the Craigieburn Range) have now closed for

the season and no other reports of large cracks like these have been

received.

Figure 7: Looking south from the top of Mt Hutt Skifield, with an example of

one of the earthquake induced full depth cracks shown in the foreground (A)

and up close (B). (Source: R. Mguire, 2010)

DISCUSSION & CONCLUSIONS

The earthquake triggered widespread avalanche activity throughout

both regions, with reported events ranging in size from D1 to D3. The

avalanches were predominantly on south and southeastern aspects,

but did occur elsewhere as well. Based on very limited observations, the

consensus seems to suggest that the avalanches primarily occurred in

the layer of buried surface hoar. The south and southeasterly aspects

likely had the most developed facets and surface hoar due to their

generally more shady exposure. They were also lee slopes during

the prior storms and definitely experienced substantial new snow

loading. Interestingly, western and northern slopes only saw isolated

events and we think that this is likely due to the general absence of

the surface hoar layer on these aspects. Additional to the avalanche

activity, full depth cracks have also been observed in the Mt Hutt

Range and these are likely to be present elsewhere. These cracks may

end up behaving like glide cracks as we progress into Spring, but given

that no one has experienced them in these locations before (unlike a

glide crack with a “normal” location), they do remain a concern.

The modeled and reported forces exerted by the earthquake (as

29

measured by the MM scale) were less over the alpine regions than

those felt in Christchurch. Despite this, the peak ground acceleration

(PGA) instruments still recorded values of between 8 and 15% gravity

(at Arthur’s Pass and Oxford respectively), meaning that a horizontal

force of about 0.08 to 0.15 times the normal load due to gravity was

exerted on the snowpack. This shaking was clearly enough to cause

substantial avalanche activity on aspects where the right mix of layers

and loading was present. Given the nature of the weakness and the

additional wind loading, these aspects may have avalanched anyway

with further loading, but it seems very likely that the shaking from

the earthquake triggered these avalanche events. This may be one of

the first recorded events where we can identify the role of grain type

on earthquake induced avalanche activity, but further work will be

needed to provide any further insight on this matter.

We were very fortunate that the earthquake occurred at 0430 in the

morning and not at 1100 on a busy Saturday, as some of these slopes

may not have seen active control and could have caught us unaware.

ACKNOWLEDGMENTS:

We acknowledge the New Zealand GeoNet project and its sponsors

EQC, GNS Science and LINZ, for providing data and images used in

this study. We also acknowledge the ongoing snow, weather and

avalanche observations from all of the contributors to the New

Zealand Mountain Safety Council Avalanche.net, but in particular;

the lead forecasters for the two regions (Kevin Boekholt and Damian

Jackson), Mt Hutt skifield, Methven Heliski, Porters skifield, Mt

Cheeseman skifield, Broken River skifield and Craigieburn Valley

skifield.

BY JORDY HENDRIKX, ANDREW HOBMAN, KARL BIRKELAND

References

Boekholt K., 2010. Mountain Safety Council Regional Avalanche

Forecaster (Mt Hutt / Arrowsmiths), IFMGA Guide, Director of

Methven Heliski & Alpine Guides. Personal communications, 22

September, 2010.

Cross, C., 2010. Christchurch earthquake’s destruction. NZ Herald

Online.

http://www.nzherald.co.nz/nz/news/image.cfm?c_id=1&gal_

objectid=10671049&gallery_id=113677#7073400 [Accessed 4

September, 2010].

GeoNet., 2010. The New Zealand GeoNet project. http://www.geonet.

org.nz/ [Accessed 17 September, 2010].

Jackson, D., 2010. Snow Safety Officer Mt Cheeseman & Mountain

Safety Council Regional Backcountry Avalanche Forecaster

(Craigieburn Range). Personal communications, 23 September, 2010.

McCammon, I., and Schweizer, J., 2002. A field method for identifying

structural weaknesses in the snowpack, paper presented at

Proceedings ISSW 2002. International Snow Science Workshop,

Penticton BC, Canada, 29 September-4 October 2002.

Mguire, R., 2010. Mt Hutt Ski Patrol. Personal communications, 12

October, 2010

Mountain Safety Council (MSC), 2010. Avalanche.net (www.avalanche.

net.nz).

Podolskiy, E.A. Nishimura, K., Abe, O., Chernous, P.A., 2010.

Earthquake-induced snow avalanches: I. Historical case studies.

Journal of Glaciology, Volume 56, Number 197, 431-446 (http://www.

igsoc.org/journal/56/197/j09j125.pdf)

William H. K. Lee, William Hung Kan Lee, International Association

of Seismology and Physics of the Earth’s Interior, Committee on

Education, Hiroo Kanamori, Paul Jennings, International Association

for Earthquake Engineering, 2003. International handbook of

earthquake and engineering seismology, Part 2, Academic Press,

1945pp.

• Helpspreventfullburialintheeventofanavalanche

• Hasbeenshowntodecreasemortalityrateto3-4%*

• HeadOnToptechnology(H.O.T)helpskeepyourheadupandyourbodyuprightintheavalanche

• H.O.T.alsoincreasestraumaprotectionforthehead,neckandchest

• 15litre,30litreand45litreversions

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*Ref:Brugger/Faulk,Analysisofavalanchesafetyequipmentforbackcountryskiers.

30

32 CRYSTAL BALL31

For many people the jury is still out on the helmet

issue. US studies that have suggested that helmets

decrease head injury in skiing and boarding by 60%

plus. But statistics from North America include

incidents that involve trees. These need to be

adjusted for any application to the NZ situation.

The pathologist observed that a the use of a helmet

would not have influenced the cause of death in any

of the cases from last year and in at least one of the

most recent fatal accidents, off the back of Mt Hutt,

a helmet was worn. North American stats also show

an increase in neck injuries in kids wearing helmets.

Finally there is the “perceived safety” mentality

(10 foot tall and bulletproof) when people slip on a

helmet.

All this aside, helmets certainly reduce the potential

impact pressures to the head. The Mountain Safety

Council’s stance is “a strong recommendation for

the use of helmets by the public” but we do not

necessarily support legislation.

IN THE FOLLOWING ARTICLE, MICHAEL LAMONT, NZ SKIFIELD INJURY RESEARCHER AND HON MEMBER OF THE INTERNATIONAL SOCIETY FOR SKIING SAFETY GIVES HIS PERSONAL PERSPECTIVE ON THE ISSUE.

32

+THE HELMET DEBATE+

Should ski-field users (skiers and snowboarders) wear a protective

helmet? The clear answer is YES – absolutely! Why and what’s the

evidence?

Firstly the ‘why’ question. To best understand that it is necessary to

understand some mechanics and some New Zealand injury statistics.

The brain is a soft and malleable structure which sits inside the

skull and is surrounded by tissues that ‘hold’ it in shape. The skull

itself is strong although its strength is not uniform - in some places

it is thicker than other places. And of course the brain is the ‘nerve

centre’ of our existence. Damage the nerve centre and we lose some

function - from small losses to very large losses. There are two forces

that cause brain trauma – the movement of the brain within the

skull and direct injuries to the skull (penetrating fractures or general

fractures which tear the inner lining tissues). The movement of

the brain within the skull is caused by deceleration forces – falling

backwards and hitting your head on concrete/ice. The brain is

damaged in 2 places – at point of contact and at the opposite side as

the brain pulls away from the supporting tissues as it moves towards

the point of contact in a deceleration mode.

Snow sports are about gaining potential energy (riding up a lift) and

expending that energy on the way down. The object is of course,

to control that energy expenditure – if it is uncontrolled an injury

is likely. Head trauma is either the first or second most common

injury on the NZ skifield. Many of the injuries are lacerations

however concussion (with or without loss of consciousness) is major

contributor to brain injuries. The cost of a death in NZ is about $2.2m

as calculated by the NZ Road Transport Authority. The 3 deaths at

Mt Hutt have cost the NZ economy $6.6m – apart from the social

loss. In the USA 1.5m people suffer from a mild traumatic brain

injury without any loss of consciousness and an equal number suffer

trauma with loss of consciousness. Some world leading research was

undertaken in NZ by the late Dr D Gronwell at Auckland Hospital.

She was able to accurately detect brain damage in a large group of

University students by some simple psychometric testing – getting

the students to do some simple writing and some simple arithmetic

deduction while oxygen was slowly withdrawn from the air – as if

gaining altitude. Those with very minor (and otherwise not noticed)

performed significantly worse than those who had not had any

‘concussion’. In contact sports (rugby, league, boxing, wrestling and

gridiron) the rule of thumb is that if a player has had a bang to the

head that has caused any loss of cerebral/motor function then they

must not play again for a month. Two episodes in a season and no

playing for a year; three episodes then no playing for life. It is very

clear in boxing to see the repeated damage to the brain – referred to as

being “punch drunk”. In the USA some research is being undertaken

using accelerometers in the helmet of gridiron players to determine

the upper limit of potentially damaging forces so that players can be

pulled from the field when they reach a critical accumulative level.

It is beyond belief that skifield users will be exempt brain trauma

when falling or stopping suddenly against an obstacle such as a rock.

Will a helmet prevent such trauma? Without a shadow of doubt. A

helmet will reduce penetrating injuries to the skull and will reduce

the deceleration forces associated with sudden stops. The helmet will

not reduce all deceleration forces particularly if there is high speed fall

but it will reduce some. All ski racers must wear a helmet; all motor

car and motor bike racers wear a helmet and there is a lot of evidence

that they do well in high speed crashes. A helmet will not stop deaths

due to other trauma – spine fractures or liver or other organ ruptures.

SHOULD YOU WEAR A HELMET? OF COURSE – IF YOU VALUE

YOUR HEAD!

I have picked up a number of people who would be alive today if they

had been wearing a helmet (penetrating injuries; ‘egg shell’

fracture; severing of part of the cerebellum during deceleration).

For more information on helmets visit www.skihelmets.org

34 CRYSTAL BALL

33

+OUTCOMES MODEL+

WE WILL LITERALLY BE ABLE TO PROJECT EACH OF THE ORGANISATIONS VISUAL OUTCOMES MODELS ONTO THE WALL AND SEE WHAT WE ARE DOING AND IDEALLY IDENTIFY WHAT WE COULD BE WORKING ON TOGETHER AND HOW WE CAN WORK SMARTER.

HOW WOULD WE KNOW IF WE GET THERE?

Having mapped our outcomes, MSC have then identified some

evaluation questions and indicators which would enable us to better

understand how well we are achieving our outcomes. This is an

ongoing process but includes external expert review, stakeholder

surveys and internal data gathering processes. The outcomes have

also been prioritised by the MSC executive which then drives our

business plan. Thus, any new projects need to clearly identify what

outcomes it is contributing towards. The visual software also enables

us to track and link projects to outcomes. Thus, any new avalanche

projects need to be clearly shown to assist the organisation to achieve

its outcomes.

WHAT DOES THIS MEAN FOR THE AVALANCHE COMMUNITY?

MSC and the Avalanche programme will have identified and prioritised

outcomes and all avalanche projects will be clearly targeted to achieving

these outcomes. In working with MSC the avalanche community can

be confident that we are focused and working hard to both achieve our

outcomes but also be able to know that we have achieved them i.e.

MSC knows where it is going and will know when we get there! There

is a great level of detail around the MSC model and outcomes models

in general. Much more detailed information, and a case study of

MSC process can be found at Duignan, P. (2010). How a not-for-profit

community organization can transition to being outcomes-focused

and results-based - A case study.  Outcomes Theory Knowledge

Base Article No. 278. (http://knol.google.com/k/paul-duignan-phd/

how-a-not-for-profit-community/2m7zd68aaz774/156 I am happy

to answer any questions or receive any comments regarding MSC

outcomes model and look forward to engaging with you to achieve

the outcomes now and in the future.

ANNIE DIGNAN

Programme Manager Research and Evaluation

New Zealand Mountain Safety Council.

WHERE ARE WE GOING AND HOW WOULD WE KNOW IF WE

ARE GETTING THERE?

WHERE ARE WE GOING?

Traditionally organisations have been able to describe their outputs,

for example, the number of manuals produced, avalanche course held

etc. However, increasingly the challenge for any organisation is to be

clear about what outcomes they are setting out to achieve and what

processes and measures they can put in place to know if they are

achieving their stated outcomes.

In 2010 MSC has been working hard to develop its outcomes model

which visually and clearly portrays what it is we are working towards

and then maps evaluation questions and indicators onto this model.

The entire model has a necessary degree of complexity, however the

diagram below provides an overview of the high level outcomes that

MSC is working towards. To read this model, start with the ultimate

outcome “people participating more safely in land based outdoor

activity” and then the steps to the left indicate the outcomes that

need to occur to achieve this.

In addition to MSC going through this process we have also shared the

skills, process and tools with a number of other outdoor and Council

organisations. What this means is that in the future many of us and

potentially all of us will all be using the same language and the same

tools to articulate our outcomes. The organisations currently involved

in this process include, NZ Alpine Club, Outdoors New Zealand, NZ

Recreation Assoc, Education Outdoors NZ and Hillary Awards. SPARC

have also been very interested in our outcomes model process and

have attended our multi organisation working group meetings. The

Department of Conservation have also recently gone through the

same process and developed an extensive visual outcomes model.

What this means for the future is that:

Page 1

34

CONTROL WORK AT DAWN TUOA SKI FEILD

36 CRYSTAL BALL

35

BAA – Backcountry Avalanche AdvisoryThe Backcountry Avalanche Advisory is provided by the Mountain Safety Council, and is available at www.avalanche.net.nz

Cov

er p

hoto

: Ava

lanc

he o

n B

all H

ut R

oad,

Aor

aki/M

ount

Coo

k N

atio

nal P

ark

Risk statement ATES and the BAA should be used together for evaluating hazards

and managing personal risk in the backcountry.There are inherent risks in backcountry travel, and most of the

routes described here will at times be unsafe due to potential snow

avalanches. The Department of Conservation has done its best to

provide accurate information describing the terrain characteristics

typical of each general region, based on its current knowledge.

However, it is up to you to use this information to make your own

risk-management decisions and learn the necessary skills for safe

backcountry travel, to access additional trip-planning materials,

and to exercise caution while travelling in backcountry areas. This

information is no substitute for experience and good judgement.

Published by Department of ConservationCanterbury ConservancyPrivate Bag 4715Christchurch, New Zealand2010

beavalanche alert

How does ATES apply in Aoraki/Mount Cook National Park?The majority of the park and surrounding terrain is serious

avalanche country. There is very little simple terrain and a moderate amount

of challenging terrain. The majority of the park is complex

avalanche terrain, which demands respect from all who

use it. See insert All park visitors should consider carefully the class of

avalanche terrain they are going into, and check the

avalanche-danger advisory prior to undertaking any trip.Avalanche seasonAt higher altitudes avalanches can occur at any time of the

year as snow falls year-round in the park. Climbers can be

at particular risk during the summer at higher elevations.

During winter and spring, avalanches can occur on some

park tracks, and on the Ball Hut road. To reduce risk, the

following applies at three sites:Hooker Valley Track During periods of high risk to people at the outlet end

•of the lake, this track is closed. You should not go

beyond the outlet end of the lake unless you have the

right avalanche experience.Ball Hut Road Large avalanches regularly cross the road each winter

•and into the spring. You should not stop in any of the

marked avalanche paths. Check with the visitor centre

for the latest avalanche information prior to walking or

four-wheel driving here.Mueller Hut Route The route to Mueller Hut travels through complex

•avalanche terrain. There is no way to avoid being

exposed to avalanche danger on this route when

there is enough snow in the start zones to produce

avalanches. Check at the visitor centre to see if

avalanches are likely to be an issue. If you lack experience at travelling in avalanche terrain,

•our recommendation is that you should only go up or

down from the hut when the avalanche danger is low. If staying overnight in the hut, you need to be

•prepared to stay longer if the danger level rises while

you are there.

Be avalanche aware!If you are going into places avalanches could occur, make

sure you: have checked the ATES class for where you want to

•go and the BAA for the avalanche rating

have the skills for the ATES class you are going into

•

take an avalanche transceiver, a snow shovel and a

•probe. Know how to use these tools!

www.doc.govt.nz

Avalanche terrain ratings

aoraki/mount cook national park

AN EXAMPLE OF HOW DOC WILL BE USING/PUBLICIZING ATES

+THE www.avalanche.net RE-DEVELOPMENT+

The Mountain Safety Council’s web site – www.avalanche.net.nz -

has long been the hub for the communication of avalanche hazard

information. After ten years of great service, it is finally time for

a makeover. The first premise of risk communication is – know

your audience. We have been doing a lot of work on understanding

whom we are communicating with and how to engage these groups.

Intensive research into out of bounds and backcountry users has

highlighted that multiple levels of approaches are required to

successfully connect with and hold this wide audience. These include

social engagement through Youtube, Twitter, Facebook and regular

community functions, talks and events. The delivery of education is

still a strong focus at all levels as is the preparation of an Avalanche

Danger Advisory. The Advisory needs to be delivered in a tiered

approach with broad regional information first followed by specific

issues (what, where, when, likelihood and consequence). Finally,

in-depth information should be available (weather, snowpack and

avalanche observations).

The use of “push techniques” is also very important in the

dissemination of information. This includes pre-recording the

advisory for radio, e-mail, txt updates and links with related websites.

Connected to this is the ease of access to the information. Although

our cell phone coverage in New Zealand may not be keeping up with

technology, the website must be accessible for modern phones to

receive forecasts and send current observations and information.

The reality of the current, and future, financial climate is that

significant external funding is required to keep the Avalanche

AN EXAMPLE OF HOW DOC WILL BE USING/PUBLICIZING ATES

TAKING A WHOLE COMMUNITY APPROACH TO RISK COMMUNICATION HAS BEEN THE BASIS OF THE NEW WEBSITE DESIGN.

programme going. The programme needs the support of the

commercial sector through sponsorship and the new website gives

the Mountain Safety Council an opportunity to promote high value

and corporate exposure to perspective sponsors. The programme also

needs the financial support of the public who are using the safety

information and again the new website allows for direct donations

and the promotion of fundraising functions and events.

It will greatly increase the ability to relate to all the people that seek

safety information and grow awareness of the avalanche issues that

may be encountered while working and playing in New Zealand’s

great outdoors.

The Mountain Safety Council hopes to be able to trial the new website

by late summer and have it ready to go by the winter of 2011. Many of

the current users completed the online survey that was attached to

the existing site and we welcome and thank you for your feedback.

Most of the comments about improvements to the website were

included in the planning process and we believe the new product will

be of a high value to all user groups. Preliminary mock-ups of the

new –www.avalanche.net website. These are concept development

images to plan the functionality and usability of the site. We are still

working on form and overall look.

38 CRYSTAL BALL41

+CRYSTAL BALL SUBSCRIPTIONS+

WE NEED YOUR SUPPORT SUBSCRIBE TO THE CRYSTAL BALL FOR 2011!

Snow study kits, Crystal Cards, Digital Thermometers and more.....

Pocket Snow Density Gauges

25, 70* 100cm Folding Snow Saws

CRYSTALBALL 2010NEW ZEALAND MOUNTAIN SAFETY COUNCIL

AVALANCHE MAGAZINEVOLUME 20

Name. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Postcode. . . . . . . . . . . . . . . . . .

Phone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Email. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

POST TO: New Zealand Mountain Safety Council PO Box 6027 Wellington

EMAIL: orders@mountainsafety.org.nz

+KNOW BEFORE YOU GO+

40 CRYSTAL BALL

BCA

Tracker avalanch

e transceiver train

ing parks are open

and available to all

backcoun

try enth

usiasts at fi

ve New

Zealan

d resorts. Ask th

e ski patrol for details at R

emarkables, Cardron

a, Treble Cone, P

orters or Craigieburn

. N

Z D

istributor – B

CA@

Sportive.co.n

z Ph

03 34

89 725

Visit w

ww

.mou

ntain

safety.org.nz