A study of 4 avalanche accidents in Japan during '99-'00 season

Shinji Ikeda, Toru Maehara, Ryuzo Nitta*, David Enright**

ABSTRACT: During the '99-00 season, 4 fatal avalanche accidents occurred in Japan. 7 people werekilled and 1 person is still missing. Our study points out the faults of safety measures against avalanchesand the rescue system in Japan. In Japan, persons who are buried by avalanches are rarely found aliveand often the victims· are found in the spring or early summer after the snowpack has melted. Thesefatalities were caused by the following problems. 1) No effective public avalanche bulletin. 2) Lightfamiliarization in the use of transceivers. 3) No public rescue dog system. 4) Rescuer's lack ofavalanche hazard management skills.

KEYWORDS: Japan, Avalanche accidents, Rescue, Avalanche bulletin

1. INTRODUCTION

The trend of avalanche accidents in Japan overthe last century changed in1961, frompredominantly industriaVtransportation accidentsbefore '61 to recreational accidents becomingmore frequent after '61 (Fig 1. and Fig 2.). Thistrend is similar to the USA and Canada, and it is

anticipated that back country recreationalistshereafter will increase in Japan like they havearound the world. Japan must prepare it'srereationalists and rescuers for this trend. Thepurpose of this paper is to put a light on some ofthe present faults in safety measures againstavalanches and the winter mountain rescuesystem with-in Japan.

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_Industrial- Number of accidents

35

Fig1. Avalanche accidents.(HokkaidofToyama/Nagano 1924-1992)

Fukuzawa, T. and others

Fig 2. Comparison of industrial andrecreational avalanche accidentsbefore and after 1966.Fukuzawa, T. and others

*Graduate school of Agriculture, ShinshuUniversity, 829-64, Hakuba-mura, Nagano, 399­9301 Japan;Fax: (81)261-72-6414;E-mail: wanwan@m1.interq.or.jp**Canadian Outdoor Adventure Club Hakuba4213, Otari-mura, Nagano, Japan; ,Fax: (81)261-82-3545E-mail: enright@wonder.ocn.ne.jp

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2. ACCIDENT AND RESCUE SUMMARY

STUDY CASE 1 Garagara sawa Valley, Nagano

Fig 3. STUDY CASE 1 accident area map.

Accident summary4 back country snow boarders triggered a

class 3/3.5 avalanche and 3 people were caughtand buried.Location: Garagara Sawa valley, Japan Alps,NaganoDate: 2000.02.19 ,1430Weather condition: Clear sky, light wind, mild air

temperature after 3day snowstorm (heavysnow fall and strong NW winds).

Starting zone:1900m a.s.l Happo One ridgeRunout zone 1100m a.s.lVertical drop 800mVictims: 3 New Zealand back country snowboarders were killed. No transceivers.

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Rescue summary02.191430 The a~dent occurred.1440 The accident was notified to the Happo Ski

patrol by a separate party. The Happo patrolnotified the police. A ground search wasinitiated by 2 members of another group andthe 4th member of the victims party.

1600 Helicopter search initiated by the police.02.200700 6 police tried to reach the starting zone of

the avalanche but they could not find thelocation of the slide as a result of poorvisibility.

1100-1400 Probe search by 6 polices and 8volunteers (about 15m x 80m)

1420-1500 Helicopter search by police

02.21Runoutzone

9 police and 5 local rescue team members and15 volunteers were on stand by at the base of thevalley but they were inhibited by thick fog and lightsnow fall. (deemed unsafe to search by localrescue team)1000-1130 Dog search, one dog andtrainer. (200m x 200m)Starting zone

3 police and 3 volunteers attempt to reach thestarting zone. But they were prevented byextreme wind and visibility.02.22

12 police went into the base of Garagara sawaValley but did not attempt to search by groundbecause of poor weather conditions andsuspected avalanche hazard.1145 The police attempted a helicopter search but

were deterred by poor visibility.02.23Runoutzone­0930-1015 Searched by 9 police and 1 search

dog with handler.Starting zone

6 volunteers investigate the slide crown, butare requested not to enter below the start zone bythe police rescue team. (No ground search fromstart zone to toe is ever done.)2 police stayed on near the starting zone.1030 Helicopter search by 2 helicopters.02.24--"'26Runoutzone

The police went into the base of Garagara sawaValley but did not attempt to search by groundbecause of poor weather conditions andsuspected avalanche hazard. On the 25th and26th helicopter searches were attempted.02.26End of the 1st search pertod.

~e bodies of the three victims were spottedby POIr~ helicopter over a two months period inthe spnng. The first was found May 17th in thed~b.ris a~ t~e. bottom of Garagara valley withmlnu:nallnJunes. The other 2 victims were found ata pOint ~pproximately 300 m from valley bottom ina depOSit at a bend in the track.

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STUDY CASE 2 Mt. Dainichl Dake, Japan Alps,Toyamama.

Accident summeryAccedent occured when 27 ski mountaineers

(participating in a National Mountaineering Schooltraining course) were taking a rest on a ridge at apoint 16-20 m away from the cornice edge, thehuge cornice under them failed with 11 memberson top of it. This triggered a 4.5/5 avalanche and 2members were caught and buried.Location: Mt. Dainichi Dake, ToyamamaDate: 2000.03.05Weather condition: we are uncertain of the

conditions on the accident day, but thisseasons snow fall was concentrated late inthe season in the Japan Alps and the cornicewas said to be significantly larger than in pastseasons.

Starting zone:2480m a.s.l near the peak of Mt.Dainichi Dake

Victims: 2 ski mountaineers, participating in aNational Mountaineering School trainingcourse, were killed.

Fig 4. STUDY CASE 2 accident area maR

oo...~crCD

•Fracture of 2nd.--.t: ••• • •

co.me. faU- 8E .-.

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o :0%°:oooeo 0 o. O~Victims

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: 16-20m

~...Fracture of 1st ••comicefall ••

Fig 5. STUDY CASE 2 accident site layout

Rescue summary03.051125 Avalanche is triggered by huge cornice fall.

10 instructors start transceiver and probesearch from start zone.

1258 A police mountain rescue officer (rescue sitecommander) is carried by helicopter toaccident site for inspection and sitecoordination.13 police carried by helicopter toaccident site and start transceiver and probesearch at starting zone. Some instructorscontinue transceiver and probe search downavalanche track but they're efforts werehindered by another cornice fall adjacent tothe initial cornice fall.

1300 The victims back packs and equipment werefound by helicopter search on the track.Transceiver signal picked up at 1440 m a.s.lfrom helicopter. But secondary avalanchedanger is jUdged as too high to allow groundsearchers in to the area, which is situated in adepression terrain trap at the base area of thelarge steep walled basin rimmed with a hugecomice.

1752 3 rescuers injured by Second cornicefall.(1851 injured searchers evacuated byhelicopter)

1808 closing of first days search.03.06

16 instructors and 14 polices were carried byhelicopter to the accident site. But the area is

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deemed too unsafe to proceed with a groundsearch as the secondary avalanche hazard is toogreat. Transceiver signal is picked up once againat 1440 m a.s.l by helicopter searchers. But theavalanche hazard is still judged as too high tosearch area as the burial depth is estimated at 7mjudging from the signa1 from the transceiveraboard the helicopter. Some of the victimsequipment was recovered by the helicopter crewin the area of the signal. Second search dayfinishes with 8 instructors and 10 police staying onnear the hut.03.07-03.09

Search is prevented by snowstorm.03.10

The area with it's high avalanche hazard isdeemed to dangerous to proceed with.Close of 1st period of search.

One victim was found July by transceiver (He usan Alpine Beacon 1500 with a 6V lithium batteryand 1500 hour lifetime) and the other (He used anOrtovox F1 focus was not working when found)was found August after snow melt.

STUDY CASE 3 Anagdani Valley, Gifu.

Accident summeryA day before the accident there was a late

season snow fall. The day of the accident twoconstruction workers who were moving snow forthe inspection of a new dam in the Anagedanivalley, were caught and buried by a 4.5/5 naturaltriggered avalanche.Location: Anage Dani Valley, Mid Japan Alps, G'Date: 2000.03.27 1150Weather condition: Day after late season heavy

snow fall. mild, overcast dayStarting zone:2700m a.s.1 near the peak of

Mt.kasagatakeRunout zone 1150m a.s.1Vertical drop 1550mHorizontal length 4600 mVictims: 2 snow removal workers killed ( found at

03.30 ). No transceivers.Rescue summary03.271150 No lunchtime contact to fellow worker.

Fellow worker concerned with lack of conproceeds to work site to find avalanche sand notifies base.

1330-2400200 people and 15 constructionmachines search the area of probable bu

03.280500-0900 180 people and 15 construction

machines search area.

Fig 6. STUDY CASE 3 accident area map,

03.29Safety check from helicopter, no ground search.

03.300330-1200160 people and 4 construction

machines and 2 dogs search accident site.0645 One victim is found away from the snow

removal machine.1126 The other victim was found again away from

the snow removal machine.Note: They are not found by the search dogs

but by trench style searching using backhoes. (scent of machine oil and hundreds ofpeople a slight over load for the dogs)

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STUDY CASE 4 Mt. Niseikausyupe, HokkaidoAccident summery

Accident occurred while 4 climbers ascended Mt.Niseikausyupe. 2 climbers were caught and buried.1 of these persons managed to undig themselvesand the other was not located until July 2nd

.

Location: Mt. Niseikausyupe, HokkaidoDate: 2000.02.131025Victims: One climber was killed. No transceivers.

3. DISCUSSION AND CONCLUSION

3.1 AVALANCHE BULLETINThree of the four cases looked at within this

paper (STUDY CASE 4, conditions unknown.)were clearly due to a lack of precaution with inavalanche terrain.STUDY CASE 1; snow boarding on a high angle

lee ward slope right after a large snowfall and highwinds.STUDY CASE 2; snow fall was concentrated I~te

in the season and cornices were much larger thanpast seasons, yet the climbers were too many insuch a small area too close to a cornice whichshould have been avoided.STUDY CASE 3; The day previous the accidentsaw a late season snow fall which loaded theslopes far up the valley.However, there was never any bulletin to

precaution any of these parties nor wasinformation spread generally within themountaineering community about unusually largecornices. In Japan there is no public avalanchebulletin other than a constant avalanche warningthat is posted from December through May, everyday with no differentiating between high and lowhazard. (Table 1.). The problems with thisavalanche warning system are as follows; A; alack of parameter. B; only two danger levels;CAUTION or NO HAZARD. C; bulletin nearlyalways indicates CAUTION during winter and earlyspring. D; Use of low elevation data collectingareas that have little or no meaning at elevation.

3.2 Transceivers, 99~O season in Japan 8 people were caught

by avalanche but only two of them were usingtransceivers. We don't know the victims avalancheknowledge but this fact is symbolic of a lack ofknowledge and respect of avalanche danger andsafety measures. It has only been in the last fewyears that magazines have been stressing the useof transceivers in Japan. Many ski hills withavalanche potential are not trained to operateavalanche transceivers at a professional level.With more and more people moving away from theski hills and into the back country it is essential forJapan (as other countries) to create a greaterawareness and respect for avalanches, and toincrease public awareness of available safetyequipment and its proper use. Yet still pUblicopinion in Japan is that the Winter mountains aredangerous and Winter back countryrecreationalists only place a burden on theshoulders of rescuers. Thus the public do notencourage avalanche awareness training as it isseen as only encouraging excursions intodangerous terrain.

Surfaceavalanche

Full depthavalanche

Gifu

SurfaceavalancheFull depthavalanche

Toyama

Surfaceavalanche

CDsnow depthG50cm andNew snowG20cm/24h andAverage wind speedG 10m/s®Snow depthG70cm andNew snowG30cm/24hCDsnow depthG70cm and Max. air

temperature G usual Max. airtemperature +5°C

®snow depth G 70cm and rainfall

snow depthG70cm andNew snow~30cm/24hCDsnow depthG70cm and

Av. air temperature G +2"C®snow depth G 70cm and rain fall

Snow fallG 90cm

3.3 RESCUE

3.3.1 RESCUE DOGSIt is certain that a dog search is the best way

to search for buried victims who are withouttransceivers. Some individuals train search dogsbut Japan does not have a public search dogsystem. The lack of an organized dog responsesystem seriously hinders a speedy rescue as ittakes far to long to locate a dog and handler, thento transport that search team to the accident site.STUDY CASE 1; A dog and handler join therescue on the third day of the search.STUDY CASE 3; Two dogs join the rescue on theforth day of the rescue after heavy machinery andhundreds of people had left their scent over theentire search area). Another serious problem isthe policy of not using out of prefecture dogs andhandlers. (STUDY CASE 1; A dog and handlerware located and on stand by to assist on thesecond day of the search, but because it was anout of prefecture team it was not granted, withwhat might be equated to, search privileges.)

3.3.2 RESCUER'S AVALANCHE HAZARDMANAGEMENT SKILLS

One of the most serious problems are rescuersavalanche hazard management. STUDY CASE 2;3 rescuers were injured by second cornice fall. InSTUDY CASE 1; rescue was hindered bysuspected avalanche hazard in a single track

Snow depth;?;50cm andDaily avo air temoerature~+5°C

New snoWG30cml24h

Snow depthG 100cm andD . t tu >+2"C•

Sapporo(Hokkaido)

Full depthavalanche

Surfaceavalanche

Full depth

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valley that was slid clean. The area was onlysearched at the bottom of the valley with outinspection from the top, nor was there a snowprofile dug to determine the stability above thearea deemed unsafe to enter. Another example isSTUDY CASE 3; where on the 1st and 2nd day180-200 rescuers were searching at the accidentsite without enough an avalanche safety check,nor were transceivers used. Of course we all knowavalanche safety judgment to be a diffICult task butmost of the time rescuers judge only terrainwithout enough snow condition data or other timesuse inadequate equipment such as thermometersinstalled on wristwatches to determine airtemperature. So it is clear that Japan rescuer'sknowledge of avalanche safety is far behind othernations with similar avalanche hazard. There ishowever a movement, however still small, toenhance the present system with training inavalanche awareness and forecasting, as well asthe use of explosives in rescue situations. At thepresent there are only two ski hills in Japan thatuse hand charges to control avalanches and ahandful more that use stationary propane cannons.

The laws are such that dynamite cannot betransported by helicopter which drastically hindersaccident prevention and rescue efforts in theWinter mountains. It seems prudent that Japan

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receive assistance, in restructuring their Wintermountain rescue system, from more progressiveprograms in Europe or North America. This wouldinclude systemized snow profiles and forecasting(bulletins), search & rescue/search dog protocol·and explosive control training. With the support ofoutside influences and a willingness to restructurethe present avalanche control and aovancedwarning systems along with increasedexperienced rescue training Japan, could over thenext decade, produce an internationalstandardized avalanche awareness and rescuesystem that would greatly benefit it's own peopleand the intemational mountaineering/recreationalcommunity.

4. ReferencesAkitaya, E., M. Abe, R. Naruse, K. Higuch, T.Fukuzawa, 1996: Update introduction toavalanche study. YAMA-KEI Publishers Co.,Ltd.Jamieson, B., T. Geldsetzer, 1996: AvalancheAccidents in Canada Volume 41984-1996.Canadian Avalanche Association.Logan, N., D. Atkins, 1996: The Snowy TorrentsAvalanche Accidents in the United States, 1980­1986. Colorado Geological Survey SpecialPublication.