First ever release of USGS offshore arctic resource assessment: Alaska Platform, South Kara Sea have greatest potential

To provide a perspective on the arctic resource potential, the US Geological Survey (USGS) recently assessed the undiscovered oil and gas resources north of the Arctic Circle. The Circum-Arctic Resource Appraisal (CARA) includes probabilistic estimates of the numbers, sizes, and aggregate volumes of yet-to-find oil, gas, and natural gas liquids in undiscovered accumulations (Gautier et al. 2009). The initialpaper recognizes that most undiscovered resources probably would be found on the continental shelves, but this publication in Offshore isthe first release of the CARA estimate of onshore versus offshore allocation of undiscovered resources.

[ILLUSTRATION OMITTED] The offshore arctic is roughly equal parts deep ocean basin and continental shelf covered by less than 500 m (1,640 ft) of water. The geology of the deep basins suggests limited petroleum potential, but the continental shelves include some of the largest untested prospectson Earth. Only a handful of wells have been drilled offshore, but these have found numerous oil and gas accumulations, including Snovit field in the Norwegian Barents Sea and the supergiant Shtokman field in the Russian Barents Sea. In spite of these successes, remoteness and technical difficulty severely restrict offshore activity, so most of these offshore discoveries remain undeveloped. USGS assessment The CARA was a geology-based, probabilistic study of the potentialfor new discoveries north of the Arctic Circle of conventional oil and/or gas in accumulations larger than 50 MMbbl of oil or 300 bcf of natural gas. So-called unconventional resources such as coal bed methane, heavy oil and bitumen, and gas hydrates are not evaluated. [ILLUSTRATION OMITTED] As petroleum is found almost exclusively in sedimentary rocks, thefirst step in assessment was to construct a consistent map of the arctic sedimentary basins, delineated according to geologic age, tectonic history, thickness of sedimentary strata, and structural style (Grantz et al. 2009). The new map helped subdivide the arctic into geologically defined subsets called Assessment Units (AUs). Sixty-nine AUswere defined based on the new mapping; their boundaries are available online (USGS 2009). The fundamental question of petroleum potential is whether the mapped AUs contain undiscovered oil and gas. Based on geological criteria, each AU was evaluated for the likelihood (the marginal probability) of occurrence of at least one undiscovered accumulation larger thanthe 50 MMboe minimum accumulation size, in comparison to all other AUs of the arctic and to similarly defined AUs worldwide. Those AUs with proven discovery histories, such as the Alaska Platform, which includes Prudhoe Bay and many other petroleum accumulations, were assigned a marginal probability of one. Other AUs were ranked and assigned lower probabilities; AUs judged to have less than a 0.1 probability of undiscovered accumulations were dismissed. Forty-eight of the 69 AUs were assessed quantitatively using a geologically based probabilistic methodology of burial-history analysis and analog modeling (Gautier et al. 2009). The range of numbers of undiscovered accumulations, the size-frequency distribution of undiscovered accumulations, and the likelihood of oil versus gas in each undiscovered accumulation were evaluated for each quantitatively assessedAU and the resulting distributions combined using a Monte Carlo simulation. The individual AU assessments then were aggregated statistically (Schuenemeyer 2009) into CircumArctic totals, taking into accountpair wise geologic correlations among AUs. Results The USGS estimates that 44 to 157 Bbbl of oil could be added to proved reserves from new discoveries north of the Arctic Circle and that there is a 50% chance of finding 83 Bbbl of oil. Approximately 73% of this amount, almost 61 Bbbl of oil, is expected to be found offshore. All 49 assessed AUs are thought to contain undiscovered oil, but most of the resource is concentrated in just seven of them. The AlaskaPlatform, in particular, with 27.9 Bbbl of oil, accounts for more than 31% of the mean estimate. More than 60% of this volume is estimated to be offshore. The adjacent Canning-Mackenzie AU, with a mean estimate of 6.4 Bbbl of oil, also is expected to house most of its undiscovered oil resource offshore in the Mackenzie Delta. The resources ofthe North Barents basin, with 5.3 Bbbl of oil, are almost entirely offshore, as is most of the 4.9 Bbbl of oil estimated in the NorthwestGreenland Rifted Margin AU. Resources of the two AUs on the northeast Greenland shelf, South Danmarkshavn basin (4.4 Bbbl of oil) and theNorth Danmarkshavn salt basin (3.3 Bbbl of oil) also are found mainly offshore. Of the most oil-prospective AUs, only Yenisey-Khatanga, to the east of the northern West Siberian basin, with 5.3 Bbbl of oil,is primarily onshore. Like the discovered accumulations, undiscovered gas is much more abundant than oil in the arctic, and most resources are expected to beoffshore. The USGS estimates a high probability that more than 770 tcf of undiscovered, conventional gas occurs north of the Arctic Circle, and that as much as 2,990 tcf may be found. The mean estimated gasresource of 1,547 tcf would be an important addition to world gas reserves. Of this amount, almost 77% is expected to be found mainly in Russian territory under relatively shallow water in the continental shelves of the South Kara Sea and the east Barents Sea. Two-thirds of the undiscovered gas is in just four AUs: South KaraSea (607 tcf), South Barents basin (184 tcf), North Barents basin (117 tcf), and the Alaska Platform (122 tc0. Of these, the South Kara Sea, and the Barents basins are almost entirely offshore. The South Kara Sea, the seaward extension of the northern West Siberian basin, isestimated to hold 39% of the aggregate undiscovered gas, and is the most prospective hydrocarbon province in the arctic. In gas volume, only the Alaska Platform is thought to hold a large part of its undiscovered resource onshore in the Brooks Range foothills. The possibility of finding large fields is as important as total resource volumes to determine the development potential of frontier provinces such as those of the arctic. The largest estimated undiscovered gas accumulation in the arctic is almost eight times the size of the largest undiscovered oil accumulation (22.5 Bboe in the South KaraSea versus 2.9 Bbbl of oil in the Alaska Platform). Although the assessment says it is unlikely that an oil field as large as Prudhoe Baywill be found again, nevertheless the arctic could contain some of the largest gas accumulations ever located. Eleven AUs are estimated to have a 50% chance of an undiscovered oil or gas accumulation with more than 1 Bboe recoverable resources. These are: South Barents basin, South Kara Sea, Yenisey-Khatanga, Alaska Platform, Canning-Mackenzie Deformed Margin, South Danmarkshavn basin, North Danmarkshavn salt basin, North Barents basin, Northwest Greenland Rifted Margin, Lena Prodelta, and Baffin Bay basin. Geology of the arctic indicates abundant, diverse, and widespread continental shelf offshore oil and gas exploration opportunities. Although the volume of undiscovered arctic oil may not rival the Middle East, it will be important to arctic nations. The mean oil estimate is more than double the amount previously found in the arctic. The onshore part of the Alaska Platform is a famous petroleum producing areaalready. Indications are that the Chukchi and Beaufort seas offshoreAlaska, along with adjacent areas of the Mackenzie Delta, may be themost oil prospective area north of the Arctic Circle. New finds could maintain the flow of Alaskan oil for years to come and significantly contribute to Canadian oil production. Initial moves toward leasingare going forward in east and west Greenland. These first estimates are intended to provide a baseline for considering arctic oil and gas resources. In many cases these estimates are based on very limited geological information, so our understanding of arctic resources is certain to change as new data become available. Moreover, while geological risks are included explicitly in the study, technological or economic risks are not. In addition to the numbers and sizes of undiscovered accumulations that might be present, discovery and development will depend upon market conditions, technological innovation, and political decisions. The Arctic Circle encompasses more than 21 million sq km (8 million sq mi), roughly one-third of it dry land. Onshore, more than 400 oil and gas accumulations have been found already, including Prudhoe Bay, the largest oil field in North America, and Yamburgskoye, the largest hydrocarbon accumulation in the arctic and one of the largest known gas fields. Eight of the world's 25 largest gas fields have been discovered in arctic Russia. In recent years, the thick, multi-year sea ice that historically limits access to the Polar Sea has been thinning and retreating, revealing wide areas of open water in the late summer. These trends suggest that the arctic could become an area of seasonal rather than permanent ice. The prospect of easier access, together with restricted exploration opportunities elsewhere, has brought the possibility of development to the attention of both arctic nations and upstream exploration companies. However, the volume and distribution of arctic oil or gas is one of the greatest uncertainties in the future of petroleum exploration. O Contacts Donald L. Gautier (1) *, Kenneth J. Bird (1), Ronald R. Charpentier (2), Arthur Grantz (3), David W. Houseknecht (4), Timothy R. Klett (2), Thomas E. Moore (1), Janet K. Pitman (2), Christopher J. Schenk (2), John H. Schuenemeyer (5), Kai Sorensen (6), Marilyn E. Tennyson (2), Zenon C. Valin (1) and Craig J. Wandrey (2) 1. US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 USA 2. US Geological Survey, Box 25046 Federal Center, Denver, CO 80225 3. 930 Van Auken Circle, Palo Alto, CA 94303 4. US Geological Survey, 12201 Sunrise Valley Drive, Reston, VA 20192 5. Southwest Statistical Consulting, 960 Sligo Street, Cortez, CO 81321 6. Geological Survey of Denmark and Greenland, Oster Voldgade 10, DK-1350 Copenhagen K Denmark * Correspondence should be emailed to gautier@usgs.gov References 1. Donald L Gautier, K. f Bird, R. R. Charpentier, Arthur Grantz, D. W. Houseknecht, T. R. Klett, T. E. Moore, J. K. Pitman, C. J. Schenk, J. H. Schuenemeyer, Kai Sorensen, M. E. Tennyson, Z. C. Valin andC. J. Wandrey, 2009, Assessment of Undiscovered Oil and Gas in the Arctic: Science, v. 329, May 2009, p. 1,175-1,179. 2. A. Grantz, R.A. Scott, S.S. Drachev, and T.E. Moore, Maps showing the sedimentary successions of the arctic region (58[degrees]-64[degrees] to 90[degrees] IV) that may be prospective for hydrocarbons (American Association of Petroleum Geologists GIS-UDRIL Open-File Spatial Library, 2009; http://gisudril.aapg.org/gisdemo/ ). 3. U.S. Geological Survey, Circum-Arctic Resource Appraisal (northof the Arctic Circle) Assessment Units GIS Data (2009); http://energy.usgs.gov/arctic/ . 4. J.H. Schuenemeyer, Procedures for Aggregation Used in the Circum-Arctic Resource Appraisal (U.S. Geological Survey Open File Report,2008- in press," http://energy, usgs.gov/arctic/). Summary of Assessment Results Offshore Allocations Assessment Assessment Unit Unit Assessment Unit Name Code Probability Main Basin Platorm TPB2 1.000 Kolguyev Terrace EBB1 1.000 South Barents Basin and Ludlov Saddle EBB2 1.000 Northern West Siberian Onshore Gas WSB1 1.000 South Kara Sea Offshore WSB2 1.000 Yenisey-Khatanga Basin YK2 1.000 Barents Platform South BP2 1.000 Arctic Norwegian Sea NM1 1.000 Alaskan Platform AA1 1.000 Alaskan fold-and Thrust-Belt AA2 1.000 Canning-Mackenzie Deformed Margin AM1 1.000 Sverdrup Mesozoic SB1 1.000 South Danmarkshavn Basin EGR2 0.720 North Danmarkshavn Salt Basin EGR1 0.648 West Laptev Grabens--Total LSS1 0.542 Foredeep Basins TPB3 0.540 Alaska Passive Margin AM2 0.540 Canada Passive Margin AM4 0.540 North Barents Basin EBB3 0.504 North Kara Basins and Platforms NKB1 0.504 Zyryanka Basin ZB1 0.504 Lincoln Sea Basin NGS1 0.504 Khatanga Saddle YK1 0.500 Northwest Greenland Rifted Margin WGEC2 0.500 Northeast Canada Rifted Margin WGEC3 0.500 Western Barents Margin NM2 0.490 Thetis Basin EGR4 0.486 Lena-Anabar Basin--Total LA1 0.462 Anisin-Novosibirsk Basins LSS3 0.432 Lena Prodelta EB1 0.432 Siberian Passive Margin LM3 0.420 Northwest Laptev Sea Shelf NWLS1 0.400 Northern Priverkhoyansk Foredeep LV1 0.400 Barents Platform North BP1 0.360 Lower Paleozoic Subsalt and Carbonate NWC2 0.324 Platform Greater Ungava Fault Zone WGEC5 0.300 Vilkitskii Basin VLK1 0.288 Liverpool Land Basin EGR5 0.288 Baffin Bay Basin WGEC4 0.280 Northeast Greenland Volcanic Province EGR3 0.256 Nansen Basin Margin EB2 0.252 Eurekan Structures WGEC1 0.250 North Chukchi-Wrangel Foreland Basin NCWF1 0 240 East Siberian Sea Basin ESS1 0.224 Wandel Sea Basin NGS2 0.224 Banks Island-Sverdrup Rim SB3 0.216 Hope Basin HB1 0.168 Makarov Basin Margin LM1 0.140 Devonian Reefs and Clastic Wedge NWC1 0.100 Western Franklinian Shelf FS1 0.090 Eastern Franklinian Shelf FS2 0.090 Boothia-Cornwallis Uplift FS3 0.090 Novaya Zemlya Basins and Admiralty NZAA1 0.090 Arch Long Strait LS1 0.084 Nansen Basin EB3 0.081 Lena-Anabar Basin Updip LA2 0.080 Amundsen Basin EB4 0.072 Sukhan-Motorchun Riphean Rift LA3 0.072 Jameson Land Basin EGR6 0.072 Sverdrup Upper Paleozoic SB2 0.072 Tunguska Basin TUN1 0.056 Jan Mayen Microcontinent JMM1 0.056 Chukchi Borderland CB1 0.054 Canada Basin AM3 0.050 Jameson Land Basin Subvolcanic EGR7 0.042 Extension Podvodnikov-Makarov Basins LM2 0.040 East Laptev Horsts LSS2 0.030 Northwest Izhma-Pechora Depression TPB1 0.020 Northwest Mezen' Basin MZB1 0.005 Total Oil (MMBO), % Oil Vol Assessment Unit Name Mean Offshore Main Basin Platorm 1,612.35 14.00 Kolguyev Terrace 145.40 93.00 South Barents Basin and Ludlov Saddle 1,938.93 100.00 Northern West Siberian Onshore Gas 1,152.43 25.00 South Kara Sea Offshore 2,507.44 100.00 Yenisey-Khatanga Basin 5,256.84 4.00 Barents Platform South 1,656.60 100.00 Arctic Norwegian Sea 1,227.50 100.00 Alaskan Platform 27,851.06 60.00 Alaskan fold-and Thrust-Belt 2,109.80 80.00 Canning-Mackenzie Deformed Margin 6,380.64 90.00 Sverdrup Mesozoic 427.10 60.00 South Danmarkshavn Basin 4,384.12 100.00 North Danmarkshavn Salt Basin 3,274.31 100.00 West Laptev Grabens--Total 2,646.35 90.00 Foredeep Basins 54.87 13.00 Alaska Passive Margin 972.23 100.00 Canada Passive Margin 2,370.71 100.00 North Barents Basin 5,322.16 100.00 North Kara Basins and Platforms 1,807.26 100.00 Zyryanka Basin 47.82 0.00 Lincoln Sea Basin 866.65 100.00 Khatanga Saddle 326.90 23.00 Northwest Greenland Rifted Margin 2,746.16 95.00 Northeast Canada Rifted Margin 849.58 100.00 Western Barents Margin 209.79 100.00 Thetis Basin 537.01 100.00 Lena-Anabar Basin--Total 1,912.89 7.00 Anisin-Novosibirsk Basins 469.22 100.00 Lena Prodelta 978.50 100.00 Siberian Passive Margin 983.55 100.00 Northwest Laptev Sea Shelf 172.24 100.00 Northern Priverkhoyansk Foredeep 376.86 0.00 Barents Platform North 368.91 100.00 Lower Paleozoic Subsalt and Carbonate 23.34 1.00 Platform Greater Ungava Fault Zone 990.84 97.00 Vilkitskii Basin 98.03 100.00 Liverpool Land Basin 209.38 100.00 Baffin Bay Basin 1,554.89 100.00 Northeast Greenland Volcanic Province 497.30 100.00 Nansen Basin Margin 363.64 100.00 Eurekan Structures 1,132.93 37.00 North Chukchi-Wrangel Foreland Basin 85.99 100.00 East Siberian Sea Basin 19.73 100.00 Wandel Sea Basin 483.15 100.00 Banks Island-Sverdrup Rim 424.01 80.00 Hope Basin 2.47 99.00 Makarov Basin Margin 123.23 100.00 Devonian Reefs and Clastic Wedge Western Franklinian Shelf Eastern Franklinian Shelf Boothia-Cornwallis Uplift Novaya Zemlya Basins and Admiralty Arch Long Strait Nansen Basin Lena-Anabar Basin Updip Amundsen Basin Sukhan-Motorchun Riphean Rift Jameson Land Basin Sverdrup Upper Paleozoic Tunguska Basin Jan Mayen Microcontinent Chukchi Borderland Canada Basin Jameson Land Basin Subvolcanic Extension Podvodnikov-Makarov Basins East Laptev Horsts Northwest Izhma-Pechora Depression Northwest Mezen' Basin Total 89,983.21 Associated/ Dissolved % Gas Vol Gas (BCFG), Assessment Unit Name Offshore Mean Main Basin Platorm 14.00 2,131.00 Kolguyev Terrace 93.00 275.04 South Barents Basin and Ludlov Saddle 100.00 3,669.27 Northern West Siberian Onshore Gas 25.00 6,859.23 South Kara Sea Offshore 100.00 14,932.53 Yenisey-Khatanga Basin 4.00 29,078.06 Barents Platform South 100.00 4,904.63 Arctic Norwegian Sea 100.00 6,409.11 Alaskan Platform 80.00 37,692.85 Alaskan fold-and Thrust-Belt 20.00 2,846.06 Canning-Mackenzie Deformed Margin 75.00 19,799.52 Sverdrup Mesozoic 60.00 2,153.94 South Danmarkshavn Basin 100.00 9,700.31 North Danmarkshavn Salt Basin 100.00 7,255.43 West Laptev Grabens--Total 90.00 3,896.93 Foredeep Basins 13.00 72.11 Alaska Passive Margin 100.00 3,021.03 Canada Passive Margin 100.00 7,348.82 North Barents Basin 100.00 10,144.56 North Kara Basins and Platforms 100.00 2,844.81 Zyryanka Basin 0.00 70.16 Lincoln Sea Basin 100.00 1,350.27 Khatanga Saddle 23.00 205.58 Northwest Greenland Rifted Margin 95.00 2,547.33 Northeast Canada Rifted Margin 100.00 786.54 Western Barents Margin 100.00 1,095.40 Thetis Basin 100.00 1,184.23 Lena-Anabar Basin--Total 7.00 1,502.25 Anisin-Novosibirsk Basins 100.00 693.00 Lena Prodelta 100.00 1,524.36 Siberian Passive Margin 100.00 1,538.15 Northwest Laptev Sea Shelf 100.00 267.13 Northern Priverkhoyansk Foredeep 0.00 296.20 Barents Platform North 100.00 1,067.33 Lower Paleozoic Subsalt and Carbonate 1.00 42.55 Platform Greater Ungava Fault Zone 97.00 2,142.81 Vilkitskii Basin 100.00 197.59 Liverpool Land Basin 100.00 463.98 Baffin Bay Basin 100.00 2,933.77 Northeast Greenland Volcanic Province 100.00 1,105.14 Nansen Basin Margin 100.00 567.92 Eurekan Structures 37.00 1,783.96 North Chukchi-Wrangel Foreland Basin 100.00 171.85 East Siberian Sea Basin 100.00 39.40 Wandel Sea Basin 100.00 752.91 Banks Island-Sverdrup Rim 80.00 1,319.43 Hope Basin 99.00 4.84 Makarov Basin Margin 100.00 193.34 Devonian Reefs and Clastic Wedge Western Franklinian Shelf Eastern Franklinian Shelf Boothia-Cornwallis Uplift Novaya Zemlya Basins and Admiralty Arch Long Strait Nansen Basin Lena-Anabar Basin Updip Amundsen Basin Sukhan-Motorchun Riphean Rift Jameson Land Basin Sverdrup Upper Paleozoic Tunguska Basin Jan Mayen Microcontinent Chukchi Borderland Canada Basin Jameson Land Basin Subvolcanic Extension Podvodnikov-Makarov Basins East Laptev Horsts Northwest Izhma-Pechora Depression Northwest Mezen' Basin Total 200,882.66 Natural Nonassociated Gas Liquids Gas (MMBNGL), (BCFG), Assessment Unit Name Mean Mean Main Basin Platorm 49.38 2,859.02 Kolguyev Terrace 3.73 2,313.49 South Barents Basin and Ludlov Saddle 49.61 183,688.61 Northern West Siberian Onshore Gas 141.51 22,418.25 South Kara Sea Offshore 308.25 607,288.55 Yenisey-Khatanga Basin 786.38 68,883.50 Barents Platform South 108.47 15,241.22 Arctic Norwegian Sea 173.18 20,645.68 Alaskan Platform 1,011.71 121,860.59 Alaskan fold-and Thrust-Belt 76.42 58,998.09 Canning-Mackenzie Deformed Margin 148.99 16,102.74 Sverdrup Mesozoic 18.31 2,798.29 South Danmarkshavn Basin 761.06 26,251.49 North Danmarkshavn Salt Basin 569.91 32,755.65 West Laptev Grabens--Total 104.68 25,193.89 Foredeep Basins 1.67 4,000.46 Alaska Passive Margin 22.71 2,866.13 Canada Passive Margin 55.27 7,752.97 North Barents Basin 137.10 117,467.00 North Kara Basins and Platforms 68.26 12,128.78 Zyryanka Basin 1.89 1,435.83 Lincoln Sea Basin 36.56 5,208.09 Khatanga Saddle 5.55 1,797.11 Northwest Greenland Rifted Margin 57.16 15,254.18 Northeast Canada Rifted Margin 17.68 4,373.52 Western Barents Margin 29.62 4,130.82 Thetis Basin 92.86 3,206.45 Lena-Anabar Basin--Total 40.30 604.50 Anisin-Novosibirsk Basins 18.63 2,779.04 Lena Prodelta 41.10 13,981.79 Siberian Passive Margin 41.54 4,683.97 Northwest Laptev Sea Shelf 7.20 4,220.99 Northern Priverkhoyansk Foredeep 7.96 1,039.00 Barents Platform North 23.56 5,005.49 Lower Paleozoic Subsalt and Carbonate 1.77 262.79 Platform Greater Ungava Fault Zone 37.58 5,851.90 Vilkitskii Basin 3.69 5,544.28 Liverpool Land Basin 36.67 1,254.71 Baffin Bay Basin 44.40 9,338.10 Northeast Greenland Volcanic Province 86.98 3,002.67 Nansen Basin Margin 15.33 3,401.36 Eurekan Structures 47.98 6,806.04 North Chukchi-Wrangel Foreland Basin 3.18 5,893.92 East Siberian Sea Basin 0.73 579.43 Wandel Sea Basin 20.41 2,895.98 Banks Island-Sverdrup Rim 9.94 2,324.70 Hope Basin 0.10 643.33 Makarov Basin Margin 5.23 740.79 Devonian Reefs and Clastic Wedge Western Franklinian Shelf Eastern Franklinian Shelf Boothia-Cornwallis Uplift Novaya Zemlya Basins and Admiralty Arch Long Strait Nansen Basin Lena-Anabar Basin Updip Amundsen Basin Sukhan-Motorchun Riphean Rift Jameson Land Basin Sverdrup Upper Paleozoic Tunguska Basin Jan Mayen Microcontinent Chukchi Borderland Canada Basin Jameson Land Basin Subvolcanic Extension Podvodnikov-Makarov Basins East Laptev Horsts Northwest Izhma-Pechora Depression Northwest Mezen' Basin Total 5,332.16 1,467,775.19 Liquids Largest Oil Assessment Unit Name (MMBL), Mean (MMBO), F50 Main Basin Platorm 63.29 447.67 Kolguyev Terrace 61.66 109.92 South Barents Basin and Ludlov Saddle 713.92 527.36 Northern West Siberian Onshore Gas 708.15 342.09 South Kara Sea Offshore 19,170.79 550.62 Yenisey-Khatanga Basin 1,835.42 921.95 Barents Platform South 110.46 277.88 Arctic Norwegian Sea 251.66 340.51 Alaskan Platform 3,245.45 2,904.98 Alaskan fold-and Thrust-Belt 1,571.39 384.26 Canning-Mackenzie Deformed Margin 189.54 1,074.64 Sverdrup Mesozoic 135.62 124.76 South Danmarkshavn Basin 2,598.15 1,524.42 North Danmarkshavn Salt Basin 3,237.32 1,265.79 West Laptev Grabens--Total 669.83 325.10 Foredeep Basins 88.46 125.09 Alaska Passive Margin 33.68 286.43 Canada Passive Margin 91.52 369.63 North Barents Basin 456.26 2,575.63 North Kara Basins and Platforms 321.96 707.46 Zyryanka Basin 38.25 108.10 Lincoln Sea Basin 138.86 485.23 Khatanga Saddle 47.81 183.87 Northwest Greenland Rifted Margin 339.40 1,681.49 Northeast Canada Rifted Margin 97.36 615.86 Western Barents Margin 50.28 161.77 Thetis Basin 317.40 293.52 Lena-Anabar Basin--Total 16.11 619.67 Anisin-Novosibirsk Basins 74.02 182.62 Lena Prodelta 373.11 571.18 Siberian Passive Margin 124.96 278.92 Northwest Laptev Sea Shelf 112.44 159.81 Northern Priverkhoyansk Foredeep 27.70 294.57 Barents Platform North 36.22 257.02 Lower Paleozoic Subsalt and Carbonate 13.46 73.01 Platform Greater Ungava Fault Zone 123.57 920.77 Vilkitskii Basin 97.94 107.73 Liverpool Land Basin 124.18 233.98 Baffin Bay Basin 205.98 1,025.68 Northeast Greenland Volcanic Province 297.05 451.69 Nansen Basin Margin 90.72 313.70 Eurekan Structures 181.47 828.57 North Chukchi-Wrangel Foreland Basin 103.39 110.26 East Siberian Sea Basin 10.18 72.23 Wandel Sea Basin 77.25 524.31 Banks Island-Sverdrup Rim 27.34 393.52 Hope Basin 11.27 71.53 Makarov Basin Margin 19.82 246.62 Devonian Reefs and Clastic Wedge Western Franklinian Shelf Eastern Franklinian Shelf Boothia-Cornwallis Uplift Novaya Zemlya Basins and Admiralty Arch Long Strait Nansen Basin Lena-Anabar Basin Updip Amundsen Basin Sukhan-Motorchun Riphean Rift Jameson Land Basin Sverdrup Upper Paleozoic Tunguska Basin Jan Mayen Microcontinent Chukchi Borderland Canada Basin Jameson Land Basin Subvolcanic Extension Podvodnikov-Makarov Basins East Laptev Horsts Northwest Izhma-Pechora Depression Northwest Mezen' Basin Total 38,732.08 Largess Non associated Gas Assessment Unit Name (BCFG), F50 Main Basin Platorm 1,156.29 Kolguyev Terrace 851.32 South Barents Basin and Ludlov Saddle 46,514.88 Northern West Siberian Onshore Gas 4,547.04 South Kara Sea Offshore 134,632.91 Yenisey-Khatanga Basin 7,960.21 Barents Platform South 1,929.24 Arctic Norwegian Sea 3,661.23 Alaskan Platform 15,403.31 Alaskan fold-and Thrust-Belt 5,194.98 Canning-Mackenzie Deformed Margin 2,852.91 Sverdrup Mesozoic 483.28 South Danmarkshavn Basin 9,249.21 North Danmarkshavn Salt Basin 11,648.60 West Laptev Grabens--Total 2,677.77 Foredeep Basins 1,772.37 Alaska Passive Margin 1,284.61 Canada Passive Margin 1,828.61 North Barents Basin 57,976.68 North Kara Basins and Platforms 4,548.17 Zyryanka Basin 1,128.44 Lincoln Sea Basin 2,939.85 Khatanga Saddle 733.38 Northwest Greenland Rifted Margin 9,602.39 Northeast Canada Rifted Margin 3,251.93 Western Barents Margin 1,621.96 Thetis Basin 1,761.72 Lena-Anabar Basin--Total 550.29 Anisin-Novosibirsk Basins 1,096.18 Lena Prodelta 6,096.65 Siberian Passive Margin 1,527.00 Northwest Laptev Sea Shelf 2,431.18 Northern Priverkhoyansk Foredeep 605.26 Barents Platform North 2,120.64 Lower Paleozoic Subsalt and Carbonate 476.66 Platform Greater Ungava Fault Zone 5,531.24 Vilkitskii Basin 4,324.66 Liverpool Land Basin 1,399.48 Baffin Bay Basin 6,123.18 Northeast Greenland Volcanic Province 2,704.66 Nansen Basin Margin 2,396.35 Eurekan Structures 4,943.96 North Chukchi-Wrangel Foreland Basin 5,114.79 East Siberian Sea Basin 801.78 Wandel Sea Basin 3,130.81 Banks Island-Sverdrup Rim 2,226.09 Hope Basin 960.44 Makarov Basin Margin 1,483.14 Devonian Reefs and Clastic Wedge Western Franklinian Shelf Eastern Franklinian Shelf Boothia-Cornwallis Uplift Novaya Zemlya Basins and Admiralty Arch Long Strait Nansen Basin Lena-Anabar Basin Updip Amundsen Basin Sukhan-Motorchun Riphean Rift Jameson Land Basin Sverdrup Upper Paleozoic Tunguska Basin Jan Mayen Microcontinent Chukchi Borderland Canada Basin Jameson Land Basin Subvolcanic Extension Podvodnikov-Makarov Basins East Laptev Horsts Northwest Izhma-Pechora Depression Northwest Mezen' Basin Total