1. Constitution and stability of Siberian permafrost Mikhail Permyakov 1 Albert Duchkov 2 Institute of Petroleum Geology and Geophysics Novosibirsk, Russia 1 permyakovme@ipgg.nsc.ru permyakovme@ipgg.nsc.ru 2 duchkovad@ipgg.nsc.ru

2. – Institute of Petroleum and gas Geology and Geophysics (IPGG) (Novosibirsk) – Institute of Geocryology (Yakutsk) – Institute of the Earth’s cryosphere (Tyumen) – Institute of the Earth’s crust (Irkutsk)

3. Permafrost structure

4. Kazanstevskoe (QIII1) interglacial Zyryanskoe (QIII 2 ) glaciation Karginskoe (QIII 3 ) interglacial Sartanian (QIII-IV) glaciation Holocene (QIV) >50 40 30 20 15 10 5 0 th.y-s. warming cold Climate fluctuation in Pleistocene and Holocene (according to N.V. Kind) Relict permafrost was formed due to of inclement conditions in Pleistocene. At these time the huge ground massifs had been frozen on the surface and under the sea shallow. Then, during the Holocene warming permafrost was thawing from the surface, but the deep permafrost layer persisted as relict. 0°C

5. Heat flow map of Siberia (mW/m 2 ) Geological structureq, mW/m 2 Mean temperature (  С) at a depth of (km) 0,5 1 2 3 5 West-Siberia plate Siberian platform Verkhoyano-Kolymsk area 53 39 61 13 8 5 29 15 27 60 30 57 92 47 81 140 82 130

6. Southern limit of the extent of the cryolithozone during different periods of the Quarternary (Kondratieva et al., 1993). 1 - Early to middle Pleistocene, 2 - Late Pleistocene (Sartanian time), 3 - Early Holocene, 4 - Climatic optimum of the Holocene, 5 - Late Holocene, 6 - Contemporary times.

7. E.S. Melnikov, K.A. Kondratieva, G.F. Gravis, L.N. Kritsuk, S.F. Khrutskyi Khanty-Mansiysk Yakutsk

8. Thickness of the Siberian permafrost. 1 - isolines of the lower boundary depth (depth of 0  C isotherm), meters; 2 - the same for upper boundary (only in West Siberia), 3 - south boundary of permafrost.

9. Contemporary average annual surface rock temperature in Western Siberia Surface temperature Permafrost boundary

10. Permafrost upper boundary in Western Siberia Permafrost boundary Permafrost upper boundary depth

11. Permafrost lower boundary in Western Siberia Permafrost boundary Permafrost lower boundary depth

12. Permafrost thickness Permafrost boundary Permafrost thickness

13. CO 2 HSZ Thickness Permafrost boundary CO2 HSZ Thickness

14. CH 4 HSZ Thickness Permafrost boundary CH4 HSZ thickness

15. Modern parameters of the West Siberia permafrost along the meridianal cross section. A - Plots of air (Ta) and rock temperature (Ts) at depth of 15-20 m B - Permafrost (P) upper and lower boundaries Ta Ts

16. Temperature field of permafrost

17. Siberia: Temperature of air in the North of Russia (Pavlov, Ananieva, 2004)

18. Examples of the temperature profiles from West Siberia: A – from northern regions (stable permafrost), B – from regions which have non-stable permafrost (constant temperature, geothermal gradient about 0)

19. West Siberia: A-C – temperature profiles from relict (land-buried) permafrost; D - curves illustrate disintegration of relict permafrost. ABCD

20. Examples of the temperature profiles from Vilyui and Predverhoyan depressions: A and C – stable permafrost, B – non-stable permafrost A Temperature B Temperature C Temperature

21. Stability of permafrost

22. Change of temperature in dry (A) and water-saturated (B) rocks with increase of Ts from -5ºC up to 0ºC for 20 thousand years. 1 - in both cases initial distribution of temperature; (A) 2-5 – temperature profiles in 5, 10, 15 and 20 thousand years after the beginning of change Ts; (B) 2-6 - temperature profiles in 4, 8, 12, 16 and 20 thousand years after the beginning of change Ts. B Temperature profile Temperature A

23. Q – heat flow below the phase boundary; Qf – heat flow in frozen rocks; H - the ice melting heat; W – ice content; V – rate of frost penetration or thawing. Near the phase boundary Qf / Q = 1 + H  W  V / Q = N N is a criterion of permafrost temperature field stability. I.While permafrost is stable: V = 0, Qf = Q and N = 1 II.Degradation of permafrost due to a climate warming: V<0, Qf<Q, Qf / Q = N<1 III.Accretion of permafrost due to a cold snap: V>0, Qf>Q, Qf / Q = N>1 Qf/Q can be used as a tool for studying the temperature field stability of the frozen rocks and a course of permafrost evolution. This technique was applied to different permafrost areas showing that N<1, i.e. permafrost degrades everywhere

24. Map of modern trends of air temperature increase in the North of Russia, ºC/yr Long-term analysis of meteo data (Pavlov, Ananieva, 2004) suggests that warming takes place everywhere (which results in permafrost thawing with various rate)

25. Possible increase of surface temperature (  С) in Siberia if the global climate warming will take place in 21 century (according to Manabe, Wetherald, 1975, 1987; Balobaev, 1994) North. latitude Years 200020202040206020802100 500,30,71,31,82,43,1 550,40,81,42,22,83,5 600,41,01,72,53,44,4 650,51,32,03,04,25,4 70-750,61,62,53,85,27,0

26. Prognosis of the temperature changes in different blocks of Western Siberia permafrost during 21 century under influence of the climate warming. 1 – temperature profiles from cold permafrost (Arcticheskaya site, Yamal), 2 - temperature profiles from non-stable permafrost without geothermal gradient (Kostrovskaya site), 3 - temperature profiles from relict permafrost (Urengoi )

27. Expected evolution of permafrost in Russia at the moderate (1-2,5 °C growth in 50 years) scenarios of climate warming to 2020 and 2050 (Pavlov, Gravis, 2000). Seasonally frozen ground Permanently frozen ground that will thaw by 2025 by 2050 relatively stable

28. RegionGas content, billion of m 3 (min/max estimation) Timan-Pechora300/1450 Western Siberia2530/6000 Eastern Siberia2625/7400 Far East745/2300 Total amount:7200/17150 Rough estimates of expected gas content within the Russian permafrost (V. Yakushev, 2009)

29. Thank you