气候变化领域集成服务门户(CCPortal): Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia

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DOI	10.5194/tcd-9-3741-2015
	Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia
	Overduin P.; Wetterich S.; Günther F.; Grigoriev M.N.; Grosse G.; Schirrmeister L.; Hubberten H.-W.; Makarov A.
发表日期	2015
ISSN	19940432
卷号	9 期号:4
英文摘要	Coastal erosion and relative sea-level rise transform terrestrial landscapes into marine environments. In the Arctic, these processes inundate terrestrial permafrost with seawater and create submarine permafrost. Permafrost begins to warm under marine conditions, which can destabilize the sea floor and may release greenhouse gases. We report on the transition of terrestrial to submarine permafrost at a site where the timing of inundation can be inferred from the rate of coastline retreat. On Muostakh Island in the central Laptev Sea, East Siberia, changes in annual coastline position have been measured for decades and vary highly spatially. We hypothesize that these rates are inversely related to the inclination of the upper surface of submarine ice-bonded permafrost (IBP) based on the consequent duration of inundation with increasing distance from the shoreline. We compared rapidly eroding and stable coastal sections of Muostakh Island and find permafrost-table inclinations, determined using direct current resistivity, of 1 and 5 %, respectively. Determinations of submarine IBP depth from a drilling transect in the early 1980s were compared to resistivity profiles from 2011. Based on boreholes drilled in 1982-1983, the thickness of unfrozen sediment overlying the IBP increased from 0 up to 14 m below sea level with increasing distance from the shoreline. The geoelectrical profiles showed thickening of the unfrozen sediment overlying ice-bonded permafrost over the 28 years since drilling took place. Parts of our geoelectrical profiles trace permafrost flooded, and showed that IBP degradation rates decreased from over 0.6 m a-1 following inundation to around 0.1 m a-1 as the duration of inundation increased to 250 years. We discuss that long-term rates are expected to be less than these values, as the depth to the IBP increases and thermal and pore water solute concentration gradients over depth decrease. For this region, it can be summarized that recent increases in coastal erosion rate and longer-term changes to benthic temperature and salinity regimes are expected to affect the depth to submarine permafrost, leading to coastal regions with shallower IBP. © Author(s) 2015.
学科领域	borehole; coastal erosion; drilling; geoelectric field; greenhouse gas; marine environment; permafrost; porewater; sea level change; sea surface salinity; sea surface temperature; seafloor; seawater; shallow water; shoreline; submarine; Arctic Ocean; Laptev Sea; Siberia
语种	英语
scopus关键词	borehole; coastal erosion; drilling; geoelectric field; greenhouse gas; marine environment; permafrost; porewater; sea level change; sea surface salinity; sea surface temperature; seafloor; seawater; shallow water; shoreline; submarine; Arctic Ocean; Laptev Sea; Siberia
来源期刊	Cryosphere Discussions
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119857
作者单位	Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Potsdam, Germany; Mel'nikov Permafrost Institute, SB RAS, Yakutsk, Russian Federation; Arctic and Antarctic Research Institute, St. Petersburg, Russian Federation
推荐引用方式 GB/T 7714	Overduin P.,Wetterich S.,Günther F.,et al. Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia[J],2015,9(4).
APA	Overduin P..,Wetterich S..,Günther F..,Grigoriev M.N..,Grosse G..,...&Makarov A..(2015).Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia.Cryosphere Discussions,9(4).
MLA	Overduin P.,et al."Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia".Cryosphere Discussions 9.4(2015).