气候变化领域集成服务门户(CCPortal): Presence of rapidly degrading permafrost plateaus in south-central Alaska

CCPortal

DOI	10.5194/tc-10-2673-2016
	Presence of rapidly degrading permafrost plateaus in south-central Alaska
	Jones B.M.; Baughman C.A.; Romanovsky V.E.; Parsekian A.D.; Babcock E.L.; Stephani E.; Jones M.C.; Grosse G.; Berg E.E.
发表日期	2016
ISSN	19940416
卷号	10 期号:6
英文摘要	Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0°C. In this study, we document the presence of residual permafrost plateaus in the western Kenai Peninsula lowlands of south-central Alaska, a region with a MAAT of 1.5±1°C (1981-2010). Continuous ground temperature measurements between 16 September 2012 and 15 September 2015, using calibrated thermistor strings, documented the presence of warm permafrost (-0.04 to-0.08°C). Field measurements (probing) on several plateau features during the fall of 2015 showed that the depth to the permafrost table averaged 1.48m but at some locations was as shallow as 0.53m. Late winter surveys (augering, coring, and GPR) in 2016 showed that the average seasonally frozen ground thickness was 0.45m, overlying a talik above the permafrost table. Measured permafrost thickness ranged from 0.33 to > 6.90m. Manual interpretation of historic aerial photography acquired in 1950 indicates that residual permafrost plateaus covered 920ha as mapped across portions of four wetland complexes encompassing 4810ha. However, between 1950 and ca. 2010, permafrost plateau extent decreased by 60.0%, with lateral feature degradation accounting for 85.0% of the reduction in area. Permafrost loss on the Kenai Peninsula is likely associated with a warming climate, wildfires that remove the protective forest and organic layer cover, groundwater flow at depth, and lateral heat transfer from wetland surface waters in the summer. Better understanding the resilience and vulnerability of ecosystem-protected permafrost is critical for mapping and predicting future permafrost extent and degradation across all permafrost regions that are currently warming. Further work should focus on reconstructing permafrost history in south-central Alaska as well as additional contemporary observations of these ecosystem-protected permafrost sites south of the regions with relatively stable permafrost. © 2016 The Author(s).
学科领域	aerial photography; air temperature; environmental degradation; field survey; frozen ground; groundwater flow; heat transfer; permafrost; plateau; seasonality; talik; vulnerability; warming; Alaska; Kenai Peninsula; United States
语种	英语
scopus关键词	aerial photography; air temperature; environmental degradation; field survey; frozen ground; groundwater flow; heat transfer; permafrost; plateau; seasonality; talik; vulnerability; warming; Alaska; Kenai Peninsula; United States
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119549
作者单位	Alaska Science Center, US Geological Survey, Anchorage, AK 99508, United States; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Earth Cryosphere Institute, 86 Malygina Street, Tyumen, 625000, Russian Federation; Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82070, United States; Eastern Geology and Paleoclimate Science Center, US Geological Survey, Reston, VA 20192, United States; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, 14473, Germany; Kenai National Wildlife Refuge, US Fish and Wildlife Service, Soldotna, AK 99669, United States
推荐引用方式 GB/T 7714	Jones B.M.,Baughman C.A.,Romanovsky V.E.,et al. Presence of rapidly degrading permafrost plateaus in south-central Alaska[J],2016,10(6).
APA	Jones B.M..,Baughman C.A..,Romanovsky V.E..,Parsekian A.D..,Babcock E.L..,...&Berg E.E..(2016).Presence of rapidly degrading permafrost plateaus in south-central Alaska.Cryosphere,10(6).
MLA	Jones B.M.,et al."Presence of rapidly degrading permafrost plateaus in south-central Alaska".Cryosphere 10.6(2016).