DOCSLIB.ORG

12.4 Permafrost MH

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
12.4 Permafrost MH NEWS FEATURE CLIMATE CHANGE 2007 NATURE|Vol 446|12 April 2007 A world melting from the top down Despite years of speculation, little can be said for sure about the future of the Arctic’s permafrost. But that’s no grounds for complacency, reports Gabrielle Walker. ome of Phil Camill’s trees are drunk. has brought with it a trebling of the thaw rate. For decades environmentalists have worried Once, the black spruce trees on the In some places the permafrost’s perimeter is about the possibility of this great putrefaction. plots of woodland that he monitors in retreating by 30 centimetres a year1. If this trend It has become perhaps the most cited exam- Snorthern Manitoba stood as straight continues, Camill estimates that no permafrost ple of the biogeochemical feedback that could and honest as pilgrims. Now an ever-increas- will be left in any of his five sites by the end of drastically worsen the effects of anthropo- A. COOPER/ALAMY ing number of them loll about leaning like the century. genic climate change. The idea is that humans lager louts. The decline is not in the moral Thawed-out permafrost has already under- increase levels of carbon dioxide in the atmos- standards of Canadian vegetation, but in the mined buildings, highways and other infra- phere, warming the permafrost, which in turn shifting ground beneath their roots. Once it structure from Alaska to Siberia. The damage is releases yet more carbon, warming the world was all hard, solid permafrost. Now much of it one of the most visible effects of warming tem- — and the permafrost — further still in an has thawed into a soggy sponge that no longer peratures on human activities. But the effects ever-escalating positive-feedback loop. provides a steady footing for the trees. Some on natural systems are to some extent more However, although such feedback has been contrive to grow at screwball angles; others have worrying. Buildings can be rebuilt, asphalt discussed for almost as long as the threat of drowned and been replaced by floating mats of relaid and agricultural practices changed global warming has been taken seriously by mosses or sedges. “It is really easy to tell when through adaptation, given the right policies scientists, the lack of firm data on the subject the permafrost has gone,” says Camill. “The and priorities (see page 716). But changes in is striking. “There is a lot that we don’t know at vegetation changes right before your eyes.” the vegetation and, crucially, in the soils of the this point,” says Walter Oechel from San Diego Camill, an ecologist from Carleton College frozen northern landscapes might not be so State University in California. “People haven’t in Northfield, Minnesota, has used those easy to cope with. The soils of the Arctic are quite pulled the whole picture together yet changes to trace the rate at which the perma- crammed with organic matter — a frozen res- — but what we do know is that the potential frost is disappearing. In their desperate attempts ervoir of beautifully preserved roots, leaves and amounts are huge and very, very scary.” to buttress themselves upright, his leaning other raw material that may contain as much spruces put on extra wood on the downslope carbon as the whole atmosphere. They are The big picture side of their trunks. Counting the asymmet- quite unlike soils from more temperate regions, There is no doubt that the Arctic is heating up. rical tree rings that result and measuring the which are mostly made up of the parts that the Vladimir Romanovsky from the University of distance of each tree from the current bound- bacteria cannot digest. “We are unplugging Alaska Fairbanks has collated borehole- and air- ary of the permafrost gives a measure of the pace the refrigerator in the far north,” says Camill. temperature data from throughout the Arctic2. of change. The results are shocking. An average “Everything that is preserved there is going to He found that only one region in the Arctic warming across his sites of 1.3 °C since 1970 start to rot.” had not warmed over the past 30 years — and 718 NATURE|Vol 446|12 April 2007 CLIMATE CHANGE 2007 NEWS FEATURE in the 1990s even that region joined the trend. flourish and decompose the defrosted organic its future course is even harder. In 2005, two Some places are warming at more than twice matter. The probability that the active layer researchers from Boulder, Colorado — David the global average rate. Romanovsky recently will deepen — putting a larger stash of carbon Lawrence from the National Center for Atmos- received a US$1 million grant to take this moni- up for grabs — or that the permafrost will thaw pheric Research and Andrew Slater from the toring work further with a network of stations completely depends on the type of vegetation Cooperative Institute for Research in Environ- in North America and Russia. and soil. Thus, thawing can accelerate rapidly mental Sciences — published the results of the The effect that this warming will have on the if a fire passes through a dried- first attempt to project the fate permafrost and its stored carbon will vary from out forest in the uplands, or if of the permafrost through the region to region. Not surprisingly, the most the soil contains enough ice “We are unplugging twenty-first century using the dramatic signs of thaw have come from the that thawing causes it to col- the refrigerator climate predictions of a gen- fringing, southerly regions of discontinuous lapse, creating a crater-scarred in the far north. eral circulation model (GCM). permafrost — such as Camill’s research sites ‘thermokarst’ landscape. Their results made dramatic — where the frozen layer is only a few metres Researchers expect to see the Everything that is headlines. Using figures from thick and average temperatures are already first signs of thaw in a deepening preserved there is one of the ‘high emissions’ sce- within a whisker of the melting point. In the of the active layer. But compli- going to start to rot.” narios developed by the Inter- colder Arctic the permafrost can be hundreds cations from terrain, vegetation governmental Panel on Climate of metres thick and it is harder to know what and other local conditions mean — Phil Camill Change (IPCC) in the model to expect. In principle, the thawing might be that data need to be collected resulted in 90% of the northern quite slow, with the warmth at the surface being continuously over several dec- permafrost disappearing by transmitted gradually into the colder depths. ades to pick up such a trend. Unfortunately, 2100. Of 10.5 million square kilometres of per- In practice, things are probably more complex, the relevant measurements so far have been mafrost around today, only about 1 million made and in places more precipitous. patchy and sporadic. In 1998, various organiza- it through the century. Even more worryingly, tions involved in permafrost research banded running the model with a ‘low emissions’ sce- Patchy progress together to receive funding as the Circumpolar nario still wiped out 60% of the permafrost, sug- Permafrost is defined as ground in which the Active Layer Monitoring (CALM) programme, gesting that severe losses are inevitable no matter temperature is less than 0 °C for at least two hosted at the University of Delaware in Newark, which policies are followed. And the model did successive years. But the ground in question to tackle the problem. The network now includes not take into account any further warming from does not have to be at the surface. In most places 125 active sites and has participants from 15 carbon given off in the thaw3. the top part of the soil thaws during the countries. Still, it is unlikely to bear fruit in the summer, providing plants form of spotting unequivocal Thick and thin and microbes with an trends for some time. The model has since attracted some criticism, ‘active layer’ above If measuring the most notably because its permafrost is a mere the permafrost damage done so 3.4 metres thick throughout the Arctic, which in which far is hard, is far from the hundreds of metres present in they can predicting some regions. However, Lawrence says that he has since re-run the model for a mid-way emis- sion scenario and dealt with some of the other criticisms at the same time, and the results remained more or less the same. He says that the model captures many important aspects of the Arctic system — including the hydrology and physical properties of the soil — and that the point is not so much the actual percentage of loss but the overall principle that a fright- eningly large amount of permafrost could be vulnerable to quite small changes in climate. “In this field you have to accept that we won’t have a perfect knowledge of what’s happening up there,” he says. “But we should be able to capture the fundamental properties. And so far the model shows that a major change is going to happen to the Arctic.” Perhaps the most intriguing of the com- plications that Lawrence’s original work did not address is the suspicion in the minds of some researchers that the permafrost itself is putting up a defence against the thaw — a set of negative feedbacks. For instance, Oechel points out that warmer temperatures lead to a thicker layer of moss on the surface of his research sites in the Alaskan tundra. Because 1.0. V. (CAPS), SYST. PERMAFROST ACTIVE-LAYER 1998. CIRCUMPOLAR ASSOC., PERMAFROST INT. UNEP/GRID-ARENDAL; REKACEWICZ, P.
Load more

Recommended publications
  • The Main Features of Permafrost in the Laptev Sea Region, Russia – a Review
    Permafrost, Phillips, Springman & Arenson (eds) © 2003 Swets & Zeitlinger, Lisse, ISBN 90 5809 582 7 The main features of permafrost in the Laptev Sea region, Russia – a review H.-W. Hubberten Alfred Wegener Institute for Polar and marine Research, Potsdam, Germany N.N. Romanovskii Geocryological Department, Faculty of Geology, Moscow State University, Moscow, Russia ABSTRACT: In this paper the concepts of permafrost conditions in the Laptev Sea region are presented with spe- cial attention to the following results: It was shown, that ice-bearing and ice-bonded permafrost exists presently within the coastal lowlands and under the shallow shelf. Open taliks can develop from modern and palaeo river taliks in active fault zones and from lake taliks over fault zones or lithospheric blocks with a higher geothermal heat flux. Ice-bearing and ice-bonded permafrost, as well as the zone of gas hydrate stability, form an impermeable regional shield for groundwater and gases occurring under permafrost. Emission of these gases and discharge of ground- water are possible only in rare open taliks, predominantly controlled by fault tectonics. Ice-bearing and ice-bonded permafrost, as well as the zone of gas hydrate stability in the northern region of the lowlands and in the inner shelf zone, have preserved during at least four Pleistocene climatic and glacio-eustatic cycles. Presently, they are subject to degradation from the bottom under the impact of the geothermal heat flux. 1 INTRODUCTION extremely complex. It consists of tectonic structures of different ages, including several rift zones (Tectonic This paper summarises the results of the studies of Map of Kara and Laptev Sea, 1998; Drachev et al., both offshore and terrestrial permafrost in the Laptev 1999).
    [Show full text]
  • Mineral Element Stocks in the Yedoma Domain: a First Assessment in Ice-Rich Permafrost Regions” by Arthur Monhonval Et Al
    Interactive comment on “Mineral element stocks in the Yedoma domain: a first assessment in ice-rich permafrost regions” by Arthur Monhonval et al. Anonymous Referee #2 Received and published: 4 January 2021 RC= Reviewer comment ; AR= Authors response RC: I appreciate the efforts from the authors. I understand the authors created a valuable dataset for the mineral elements in the yedoma regions, and they also tried to calculated the storage of these elements. I have some comments for the authors to improve the quality of the manuscripts. We thank the reviewer for the valuable comments and suggestions to improve the manuscript. We have revised the manuscript accordingly. Please find the details in the responses to the following comments. RC1: When the authors introduce the stocks or storage, it is necessary to clarify the depth or thickness of yedoma. At least, the authors should explain the characteristics of yedoma. This is important because the potential readers will be confused about the depth and height in the dataset. AR : We agree that the choice of the thickness used to upscale to the whole Yedoma domain was not clear in the manuscript. Here, mineral element stocks are compared with C stocks using identical Yedoma domain deposits parameters (including thicknesses) like in Strauss et al., 2013 for deep permafrost carbon pool of the Yedoma region, i.e., a mean thickness of 19.6 meters deep in Yedoma deposits and 5.5 meters deep in Alas deposits. We have revised the manuscript to include that information (L 282):” Thickness used for mineral element stock estimations in Yedoma domain deposits are based on mean profile depths of the sampled Yedoma (n=19) and Alas (n=10) deposits (Table 3; Strauss et al., 2013).
    [Show full text]
  • Permafrost Soils and Carbon Cycling
    SOIL, 1, 147–171, 2015 www.soil-journal.net/1/147/2015/ doi:10.5194/soil-1-147-2015 SOIL © Author(s) 2015. CC Attribution 3.0 License. Permafrost soils and carbon cycling C. L. Ping1, J. D. Jastrow2, M. T. Jorgenson3, G. J. Michaelson1, and Y. L. Shur4 1Agricultural and Forestry Experiment Station, Palmer Research Center, University of Alaska Fairbanks, 1509 South Georgeson Road, Palmer, AK 99645, USA 2Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA 3Alaska Ecoscience, Fairbanks, AK 99775, USA 4Department of Civil and Environmental Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775, USA Correspondence to: C. L. Ping ([email protected]) Received: 4 October 2014 – Published in SOIL Discuss.: 30 October 2014 Revised: – – Accepted: 24 December 2014 – Published: 5 February 2015 Abstract. Knowledge of soils in the permafrost region has advanced immensely in recent decades, despite the remoteness and inaccessibility of most of the region and the sampling limitations posed by the severe environ- ment. These efforts significantly increased estimates of the amount of organic carbon stored in permafrost-region soils and improved understanding of how pedogenic processes unique to permafrost environments built enor- mous organic carbon stocks during the Quaternary. This knowledge has also called attention to the importance of permafrost-affected soils to the global carbon cycle and the potential vulnerability of the region’s soil or- ganic carbon (SOC) stocks to changing climatic conditions. In this review, we briefly introduce the permafrost characteristics, ice structures, and cryopedogenic processes that shape the development of permafrost-affected soils, and discuss their effects on soil structures and on organic matter distributions within the soil profile.
    [Show full text]
  • Dissolved Organic Carbon (DOC) in Arctic Ground
    Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | The Cryosphere Discuss., 9, 77–114, 2015 www.the-cryosphere-discuss.net/9/77/2015/ doi:10.5194/tcd-9-77-2015 © Author(s) 2015. CC Attribution 3.0 License. This discussion paper is/has been under review for the journal The Cryosphere (TC). Please refer to the corresponding final paper in TC if available. Dissolved organic carbon (DOC) in Arctic ground ice M. Fritz1, T. Opel1, G. Tanski1, U. Herzschuh1,2, H. Meyer1, A. Eulenburg1, and H. Lantuit1,2 1Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Department of Periglacial Research, Telegrafenberg A43, 14473 Potsdam, Germany 2Potsdam University, Institute of Earth and Environmental Sciences, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, Germany Received: 5 November 2014 – Accepted: 13 December 2014 – Published: 7 January 2015 Correspondence to: M. Fritz ([email protected]) Published by Copernicus Publications on behalf of the European Geosciences Union. 77 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Abstract Thermal permafrost degradation and coastal erosion in the Arctic remobilize substan- tial amounts of organic carbon (OC) and nutrients which have been accumulated in late Pleistocene and Holocene unconsolidated deposits. Their vulnerability to thaw 5 subsidence, collapsing coastlines and irreversible landscape change is largely due to the presence of large amounts of massive ground ice such as ice wedges. However, ground ice has not, until now, been considered to be a source of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and other elements, which are impor- tant for ecosystems and carbon cycling. Here we show, using geochemical data from 10 a large number of different ice bodies throughout the Arctic, that ice wedges have the 1 1 greatest potential for DOC storage with a maximum of 28.6 mg L− (mean: 9.6 mg L− ).
    [Show full text]
  • Organic Carbon Characteristics in Ice-Rich Permafrost in Alas and Yedoma Deposits, Central Yakutia, Siberia” by Torben Windirsch Et Al
    Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-470-RC1, 2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Interactive comment on “Organic Carbon Characteristics in Ice-rich Permafrost in Alas and Yedoma Deposits, Central Yakutia, Siberia” by Torben Windirsch et al. Anonymous Referee #1 Received and published: 27 January 2020 The paper “Organic Carbon Characteristics in Ice-rich Permafrost in Alas and Yedoma Deposits, Central Yakutia, Siberia” by Windirsch et al. reports detailed analyses on carbon and ice contents, stable water isotopes, soil grain size distribution, and age estimates for two long ground profiles in the Central Yakutia, Russia. The presented materials are rare and highly valuable to understand landscape development and con- tents in the permafrost of the Eastern Siberia. Although I expect this paper to be finally published in Biogeosciece, the authors have not fully utilized, described, and discussed the data presented. The importance of this paper is the rareness of the sample core. I encourage the authors to enrich their descriptions about each core unit as a valuable drilling log of a permafrost region. Some portions in Discussion are C1 not logically constructed. For the main datasets of stable water isotopes and carbon parameters, a more in-depth and quantitative discussion is anticipated. Although the authors want to focus on the organic carbon characteristics as indicated in the title, more comprehensive discussion and interpretation must be done using available water geochemistry, cryostratigraphy, grain size distribution, magnetic susceptibility, etc. The usage of references or previous studies is poor and is often not clear or inappropriate.
    [Show full text]
  • How Vulnerable Is Alaska's Transportation to Climate Change?
    00_TRN_284_TRN_284 3/7/13 3:00 PM Page 23 How Vulnerable Is Alaska’s Transportation to Climate Change? Managing an Infrastructure Built on Permafrost BILLY CONNOR AND JAMES HARPER limate change is affecting transportation sys- tems across the country, and scientists and pol- Cicymakers are working to clarify the trends. Alaska’s transportation community, however, has di- rect experience to verify the impacts of climate change. Geography and extreme climate have made the state a kind of climate-change classroom for the rest of the nation in predicting the effects on trans- portation infrastructure. The wear and tear of climate change on Alaska’s transportation systems is evident. The state has more than 6,600 miles of coastline, and approximately 80 percent of the land mass has an underlayer of ice-rich permafrost. Alaska has 17 of the nation’s 20 largest mountain ranges and experiences extremes in pre- cipitation, snowfall, and temperature swings that are unique to the arctic and northern latitudes. With warming permafrost, coastal erosion, and increasingly dramatic storms and flood events, Alaska’s highways, runways, and other infrastruc- ture are frequently icing, cracking, and washing away. Although these adversities challenge all of the state’s major transportation systems—maritime, avi- ation, and surface—the most acute and costly dam- age occurs within the road system. Climate change in Alaska is forcing engineers and planners to adapt both to warming and to cooling trends. Engineers and planners are addressing knowledge gaps in thermal and hydrological dynam- ENTER C ics and are translating the findings into new and more robust designs.
    [Show full text]
  • Characteristics of Ice-Rich Permafrost Soils and Their Effect on Thermokarst Expansion Rates in Interior Alaskan Peatlands
    Characteristics of ice-rich permafrost soils and their effect on thermokarst expansion rates in interior Alaskan peatlands by Natalie Jeanne W. Zwanenburg A Thesis presented to The University of Guelph In partial fulfillment of requirements for the degree of Master of Science in Integrative Biology Guelph, Ontario, Canada © Natalie J. W. Zwanenburg, April, 2018 ABSTRACT Characteristics of ice-rich permafrost soils and their effect on thermokarst expansion rates in Interior Alaskan peatlands Natalie J. W. Zwanenburg Advisor: University of Guelph, 2018 Dr. Merritt R. Turetsky This thesis addresses two uncertainties concerning permafrost thaw in peatlands by quantifying: (i) how soil characteristics and collapse-scar feature morphology interact to influence lateral expansion rates of thermokarst features; and (ii) the consequences of thermokarst expansion rates on terrestrial carbon storage. I collected peat cores within and adjacent to collapse-scar features to develop a chronosequence of time-following-thaw. I explored feature morphology and soil characteristics using grain size analysis. Radiocarbon dating of the organic and mineral soils from each peat core was used to quantify lateral expansion and peat accumulation rates. Grain size was uniform across the study region, suggesting other physical characteristics (such as ice content and organic matter) influence thaw rate of collapse-scar features. Permafrost carbon stocks rapidly decrease post-thaw, while new surface peat carbon gradually accumulates. My findings suggest anywhere from 250-700 years of surface peat accumulation is required to compensate for deep permafrost carbon losses. iii ACKNOWLEDGMENTS First, I would like to thank my advisor, Dr. Merritt Turetsky, without your continual support this thesis would not have been possible.
    [Show full text]
  • A Song of Ice and Mud Interactions of Microbes with Roots, Fauna and Carbon in Warming Permafrost-Affected Soils
    A song of ice and mud Interactions of microbes with roots, fauna and carbon in warming permafrost-affected soils Sylvain Monteux Akademisk avhandling som med vederbörligt tillstånd av Rektor vid Umeå universitet för avläggande av filosofie doktorsexamen framläggs till offentligt försvar i N430 salen, Naturvetarhuset September 28, kl. 10:15. Avhandlingen kommer att försvaras på engelska. Fakultetsopponent: Prof. Dr., Joshua Schimel, University of California Santa Barbara, Santa Barbara,USA. Department of Ecology and Environmental Sciences Organization Document type Date of publication Umeå University Doctoral thesis 07 September 2018 Department of Ecology and Environmental Sciences Author Sylvain Monteux Title A song of ice and mud: interactions of microbes with roots, fauna and carbon in warming permafrost-affected soils Abstract Permafrost-affected soils store a large quantity of soil organic matter (SOM) – ca. half of worldwide soil carbon – and currently undergo rapid and severe warming due to climate change. Increased SOM decomposition by microorganisms and soil fauna due to climate change, poses the risk of a positive climate feedback through the release of greenhouse gases. Direct effects of climate change on SOM decomposition, through such mechanisms as deepening of the seasonally-thawing active layer and increasing soil temperatures, have gathered considerable scientific attention in the last two decades. Yet, indirect effects mediated by changes in plant, microbial, and fauna communities, remain poorly understood. Microbial communities,
    [Show full text]
  • Deposition As Cold-Climate Loess, Duvanny Yar, Northeast Siberia
    This is a repository copy of Palaeoenvironmental Interpretation of Yedoma Silt (Ice Complex) Deposition as Cold-Climate Loess, Duvanny Yar, Northeast Siberia. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/99922/ Version: Submitted Version Article: Murton, J.B., Goslar, T., Edwards, M.E. et al. (15 more authors) (2015) Palaeoenvironmental Interpretation of Yedoma Silt (Ice Complex) Deposition as Cold-Climate Loess, Duvanny Yar, Northeast Siberia. Permafrost and Periglacial Processes, 26 (3). pp. 208-288. ISSN 1045-6740 https://doi.org/10.1002/ppp.1843 Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ 1 1 Palaeoenvironmental interpretation of yedoma silt (Ice Complex) deposition as cold-climate loess, 2 Duvanny Yar, northeast Siberia 3 Julian B.
    [Show full text]
  • Soil Moisture Acknowledgements • Upwellings of Soil Due 0.7
    Effects of Disturbances on Vegetation Composition and Permafrost Thaw in Boreal Forests and Tundra Ecosystems of the Siberian Arctic Erika Ramos1, Heather D. Alexander1, and Susan Natali2 1University of Texas - Brownsville, 2Woods Hole Research Center Background Study Sites Vegetation Cover Conclusion • Climate-driven changes to Bare Ground Evergreen Deciduous Moss/Lichen Grass Other Arctic Ocean the thermal regime of permafrost soils have the Disturbed Cherskii Tundra potential to create surface Tundra disturbances that influence Undisturbed Russia Alaska Tundra vegetation dynamics and underlying soil properties. Disturbed Forest Boreal Forest Boreal • These changes are Undisturbed Forest Boreal particularly important • These results highlight important in yedoma, ice-rich • The sites were located near the Northeast 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% linkages between disturbances, permafrost which is Science Station (NESS) in Cherskii, Russia. • Both thermokarst and frost boils resulted in decreased vegetation cover vegetation communities, and common across large areas and greater exposure of mineral soils. permafrost soils, and contribute to of the Siberian Arctic. Arctic Ocean • Disturbed locations showed a significant decrease in shrub cover and an our understanding of how changes in increase in bare ground. Arctic vegetation dynamics as direct • Vegetation and the accumulation of soil organic and/or indirect consequences of matter drive ecosystem carbon (C) dynamics and climate change have the potential to contribute to
    [Show full text]
  • Permafrost - Physical Aspects, Carbon Cycling, Databases and Uncertainties
    Permafrost - physical aspects, carbon cycling, databases and uncertainties Julia Boike1, Moritz Langer1, Hugues Lantuit1, Sina Muster1, Kurt Roth2, Torsten Sachs3, Paul Overduin1, Sebastian Westermann4, A. David McGuire5 1 Alfred Wegener Institute Potsdam, Telegrafenberg A6, 14473 Potsdam, Germany, [email protected] 2 Institute of Environmental Physics, INF 229, University of Heidelberg, 69120 Heidelberg, Germany, [email protected] 3 Deutsches GeoForschungsZentrum GFZ, Telegrafenberg, B 320, 14473 Potsdam, Germany, [email protected] 4 Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, 0316 Oslo, Norway, [email protected] 5 U.S. Geological Survey, Institute of Arctic Biology, Department of Biology and Wildlife University of Alaska Fairbanks, Fairbanks, AK 99775, USA, [email protected] Permafrost - physical aspects, carbon cycling, databases and uncertainties ..................................................................................... 1 1 Permafrost: a phenomenon of global significance .............. 2 2 Permafrost: definition, distribution and history .................. 4 3 Physical factors affecting the permafrost thermal regime ... 5 3.1 Permafrost temperatures ................................................. 5 3.2 Active layer dynamics .................................................... 6 3.3 Land cover ...................................................................... 8 3.4 Surface energy balance ................................................. 10 4 Carbon
    [Show full text]
  • The Yedoma Suite of the Northeastern Siberian Shelf Region: Characteristics and Concept of Formation
    The Yedoma Suite of the Northeastern Siberian Shelf Region: Characteristics and Concept of Formation /XW]6FKLUUPHLVWHU+DQQR0H\HU6HEDVWLDQ:HWWHULFK&KULVWLQH6LHJHUW Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, D-14473 Potsdam, Germany 9LNWRU9.XQLWVN\ Permafrost Institute RAS-SB Yakutsk, 677010 Yakutsk, ul. Mersoltnaya, Russia Guido Grosse University of Alaska Fairbanks, Geophysical Institute, 903 Koyukuk Drive, Fairbanks, AK 99775, USA 7DW\DQD9.X]QHWVRYD$OH[DQGHU<X'HUHY\DJLQ Moscow State University, Geological Faculty, 11991 Moscow, Russia Abstract 7KH<HGRPD6XLWHLVZHOOH[SRVHGDORQJFRDVWVDQGULYHUEDQNVLQWKHQRUWKHDVWHUQ6LEHULDQ$UFWLF7KHFU\RWH[WXUH RIWKHVHPRVWO\LFHVXSHUVDWXUDWHGGHSRVLWVLVVLPLODUDWPRVWVLWHV²LFHEDQGVDQGUHWLFXODWHGLFHOHQVHV7KH<HGRPD 6XLWHLVFRQVLGHUHGDVHTXHQFHRIEXULHGFU\RVROVIRUPHGXQGHUSUHGRPLQDQWO\VXEDHULDOFRQGLWLRQV,WUHSUHVHQWV DQ LPSRUWDQW WHUUHVWULDOFDUERQ UHVHUYRLU 72& ±ZW 7KH PXOWLPRGDOJUDLQ VL]H GLVWULEXWLRQGRHV QRW UHÀHFW SULPDULO\DHROLDQDFFXPXODWLRQEXWUDWKHUDPL[WXUHRIYDULRXVSHULJODFLDOWUDQVSRUWDQGDFFXPXODWLRQSURFHVVHVEDVHG RQWKHFRQFHSWRIQLYDOOLWKRJHQHVLV7KH<HGRPD6XLWHDJHOLHVLQWKH0,6DQG0,6SHULRGVDQGLQUDUHFDVHV DOUHDG\VWDUWVGXULQJ0,67KHSDODHRHFRORJ\RIWKH<HGRPD6XLWHFDQEHVXPPDUL]HGLQWKHWHUP³7XQGUD6WHSSH´ FRPELQLQJERWKWXQGUDDQGVWHSSHHQYLURQPHQWDOIHDWXUHV7KHSUHVHQWRFFXUUHQFHRIWKH<HGRPD6XLWHUHPDLQVLV FORVHO\UHODWHGWRORZPRXQWDLQULGJHVVXUURXQGLQJWKHQRUWKHUQDQGQRUWKHDVWHUQ6LEHULDQVKHOYHV7KHFRQFHSWRI QLYDOOLWKRJHQHVLVLVSUHVHQWHGH[SODLQLQJWKHRULJLQRIVRXUFHPDWHULDODQGWUDQVSRUWPHGLXP Keywords: cryolithology;
    [Show full text]