seafloor mapping in the high arctic: the challenges and ...1).pdf · seafloor mapping in the high...
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Arctic Change Quebec CityArctic Change Quebec City 11 Dec 200811 Dec 2008
Seafloor Mapping in the Seafloor Mapping in the High Arctic: High Arctic:
Center for Coastal and Ocean Mapping / NOAACenter for Coastal and Ocean Mapping / NOAA--UNH Joint Hydrographic Center University of UNH Joint Hydrographic Center University of
New Hampshire, USANew Hampshire, USA
The Challenges and the JoysThe Challenges and the JoysLarry MayerLarry Mayer
Martin Martin JakobssonJakobssonDept of Geology and Dept of Geology and GeochemsitryGeochemsitry
Stockholm UniversityStockholm University
A geospatial context for our studies of Arctic change
Nansen 19071893-1896
8 soundings….
Fletcher’s Ice Island (TFletcher’s Ice Island (T--3)3)
Positioning
1962 1962 -- 19741974LOREX LOREX -- 19791979
Hydro-Hole
Echo sounder
Airborne Measurements and Point Soundings
Gravity Measurement
MagnetometerDepth Sounding
CHS & GEBCO (1967,1968,1979)
Data from Nuclear SubmarinesData from Nuclear Submarines
Sounding tracks of US Navy submarines from 1983 to 1988 Sounding tracks of US Navy submarines from 1983 to 1988 (from Bob Anderson via NGDC).(from Bob Anderson via NGDC).
http://www.ldeo.columbia.edu/res/pi/SCICEX/
SCICEX (1993-1997)
http://www.oceandata.com/images/11hrsbp.jpg
IBCAO 1999
IBCAO 1999
UNCLOS
The Drivers
Climate Change
United Nations Convention United Nations Convention on the Law of the Sea on the Law of the Sea
Article 76Article 76Six hundred and seventeen words that redefine the “continental shelf” of a coastal state and provide a mechanism for the state to extend its sovereign rights over the resources of the “seabed and subsoil” of the continental shelf
UNCLOS Article 76UNCLOS Article 76
•• A coastal state is entitled to sovereign rights over the resources of the seabed and subsoil of "submerged extensions of the continental margin" beyond their 200 nm Exclusive Economic Zone (EEZ) if….
•• Demonstrate a “natural prolongation” of the coastal state’s territorial landmass
typically broad continental shelf and/or
thick sedimentary wedge
The ProcessThe Process
• All coastal states are entitled to a 200 nm EEZ
Data RequiredData Required
•• Once the natural prolongation is established the extended continental shelf beyond the 200 nm EEZ is determined by a set of formulae and limit lines defined from the:
• depth and shape of the seafloor
• the thickness of the underlying sediments
• distances from the territorial sea baselines
(FOS and 2500m contour)(FOS and 2500m contour)
(1% line)(1% line)
(350 nm line)(350 nm line)
Need to map the seafloor
UNH CCOMUNH CCOM--JHC U.S. LawJHC U.S. Law--ofof--thethe--Sea Bathymetric Sea Bathymetric Mapping to DateMapping to Date
Mayer et al. 2002 U.S. Law-of-the-Sea Desktop Study
Marianas2006
20082008
Kingman Reef-Palmyra Atoll
soon
soon
…..Arctic2003
Bering Sea2003
…Atlantic20042004
Gulf of Mexico2007
2007
2007Gulf of Alaska
2005
2005
Arctic is unique as an ocean basin in that >52% is made up of shelf (geologic)
SemiSemi--enclosed basin with five enclosed basin with five nations having potential extended nations having potential extended
shelvesshelves
From Ron McNab
From Durham University
Session T12
Law and Politics of Canadian
Jurisdiction on the Arctic Ocean
Seabed
Single Beam Echo SounderSingle Beam Echo Sounder
MultibeamMultibeamEcho SounderEcho Sounder
A new perspective A new perspective new insightsnew insights
Arctic - Chukchi Plateau mappingUSCGC Healy
Larry
Seabeam 2112 - 12 kHz, 121-2˚ receive beamsbathymetry & acoustic backscatterKnudsen 320BR 3.5-kHz chirp profiler
UNH: bathymetry, backscatter & 3.5-kHz processing at sea
Andy
Chukchi plateau
Barrow margin
2003 & 20042007 & 2008
operations…………….……... 65 daystransits……………………..… 24 daysaverage speed (in ice)……...4 ktsaverage sea-ice state………..…9/10tracklines………………… ~24,300 km Area mapped…….…. ~135,000 km2
Arctic Mapping 2003,2004,2007,2008
cruise statistics
Healy 03Healy 03--0202
~3000 km of ~3000 km of multibeammultibeam
sonar sonar bathymetrybathymetry
11--11 Sept 0311 Sept 03
8/10 ice8/10 ice
typical ice conditions2003
8/10 “cheesy” ice
Redefinition of the 2500 m contour
3100 m high, summit at 900 m water depth
Healy SeamountHealy Seamountlooking S, looking S, veve=6x=6x
45 km long x 15 km wide
water depth (m)
Healy Seamount SurveyHealy Seamount Survey
Radarsat ice coverage for 10 October 2004. Image processed at either ASF, Qinetic or CDPF. © CSA2004
2004
Chukchi plateau
Grönland
How do we map in this?
HEALY 04-05 TRACK
6-26 Oct. 2004
6700 line km
“Ratchet Surveying”
“Pirouette Surveying”
Barrow marginlooking SE, ve=10x
2500 m
ridges<300 m high,~100 km long
erosionN
mapped 2500-m isobath
HEALY 07HEALY 07--0303Depart Barrow:Depart Barrow:
17 Aug. 0717 Aug. 07Return BarrowReturn Barrow15 Sept. 0715 Sept. 07
72°N
75°N
78°N
81°N
HEALY HEALY 07030703
mapping the2500-m isobath &foot of the slope
perspective view looking SW
2007 results
HealyHealy 0303--02, 0402, 04--05, 0705, 07--0303
HEALY 0805 HEALY 0805 –– SHIPTRACK AND DREDGE SITESSHIPTRACK AND DREDGE SITES
HEALY 0806 and LOUIS St. LAURENT WORKHEALY 0806 and LOUIS St. LAURENT WORK
Pt Barrow
2003, 2004 & 2007Arctic surveys
0 500 km
scours& bedforms
Barrow margin
λ = ~2 kmH = ~10 m
A
B
3 to 5 m deep
central ChukchiPlateau
A B
ice grooves
-380 m
-470 m
Pt Barrow
2003, 2004 & 2007Arctic surveys
0 500 km
pockmarks
Barrow margin
central Chukchi Plateau pockmarks
VE = 10xlooking SW
200-m diameter20-m deep
Lomon
osov
Ridg
e
YermakPlateau
Morris Jesup Rise
Alph
a-M
ende
leev
ChukchiBorderland
Multibeam mapping
R/V Polarstern
I/B Oden
USCGC Healy
Gakke
l Rid
ge
Mackenzie
E u
r a s
i a
n S
h e
l f
S e
a s
CCGS Amundsen
Canadian
Archipelago
• Click to edit Master text styles– Second level
• Third level– Fourth level
» Fifth level
Glacial Sole Marks
5 km
Amundsen Gulf
From S. Blasco
Gary Knolls Mud Volcanoes
Beaufort Sea
From S. Blasco
Shelf Slump
Western EdgeEastern Edge
Beaufort Shelf
From S. Blasco
More at session T34 –Seafloor Mapping of the
Arctic Ocean - Room 207
0º 45ºE 90ºE
135º45ºW
135ºW 180ºE90ºW
IODP Leg 302
SCICEX 99
AMORE, Healy/Polarstern
LOMROG 2007
HOTRAX 2005
Polarstern
Jakobsson 1999, Marine Geology
Polyak et al. 2002, Nature
Jakobsson et al. 2005, QSR
Kristoffersen & Mikkelsen 2006, Marine Geol.
Polyak et al., 2002, Nature
Morris-Jessup Rise
Nansen 1907IBCAO 2008
~~6 % OF THE ARCTIC 6 % OF THE ARCTIC OCEAN HAS BEEN MAPPED OCEAN HAS BEEN MAPPED
WITH MULTIBEAMWITH MULTIBEAM
THERE IS MUCH MUCH THERE IS MUCH MUCH MORE TO DISCOVER!!!MORE TO DISCOVER!!!
www.ccom.unh.eduwww.ccom.unh.edu
Bathymetric CompilationBathymetric Compilation
IBCAO (2002)IBCAO (2002)
??
??
??Resources of extended U.S. continental shelf Resources of extended U.S. continental shelf estimated to be worth 1.3 TRILLION $estimated to be worth 1.3 TRILLION $
MurtonMurton, B.J, Parsons, L.M., Hunter, P. and Miles, P., 2001, , B.J, Parsons, L.M., Hunter, P. and Miles, P., 2001, Global nonGlobal non--living resources on the living resources on the thethe extended continental extended continental shelf: Prospects at the year 2000, Intl. Seabed Authority shelf: Prospects at the year 2000, Intl. Seabed Authority Tech. Study No 1Tech. Study No 1