DOI: 10.1016/j.quascirev.2013.04.009
Scopus记录号: 2-s2.0-84880606349
论文题名: From mountain top to the deep sea - Deglaciation in 4D of the northwestern Barents Sea ice sheet
作者: Hormes A. ; Gjermundsen E.F. ; Rasmussen T.L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 75 起始页码: 78
结束页码: 99
语种: 英语
英文关键词: 10Be
; Bølling
; Cosmogenic nuclide dating
; Heinrich 1 event
; Last Glacial Maximum
; Meltwater pulse 1a
; Spitsbergen
; Svalbard
Scopus关键词: Cosmogenic nuclide dating
; Heinrich 1 event
; Last Glacial Maximum
; Meltwater pulse 1a
; Spitsbergen
; Svalbard
; Incident solar radiation
; Isotopes
; Sea ice
; Sea level
; Submarine geology
; Glaciers
; archipelago
; atmospheric circulation
; beryllium isotope
; cosmogenic radionuclide
; deep sea
; deglaciation
; geochronology
; Heinrich event
; ice retreat
; ice sheet
; insolation
; Last Glacial Maximum
; meltwater
; paleoceanography
; radiocarbon dating
; sea level change
; Arctic
; Arctic Ocean
; Barents Sea
; Svalbard
; Svalbard and Jan Mayen
英文摘要: The timing of the deglaciation of the northern Barents Sea ice sheet (BSIS) documented in terrestrial and offshore records from the Svalbard archipelago is reviewed. We present new cosmogenic nuclide (CN) ages from formerly unexplored inland areas of northern Svalbard to investigate the timing of thinning of past local ice domes. CN data are compared with radiocarbon ages from marine and terrestrial deposits. 10Be isotope CN dates on erratic boulders from interior Svalbard suggest that glacier surfaces in northern and western Svalbard thinned 950-650m from 26±4ka and continued over an extended period until 16ka. Initial ice retreat from the western outer to the inner shelf began at 20.5ka and in Storfjordrenna southwest of Svalbard around 19-18ka. Retreat of grounded ice from the northern outer to the inner shelf did not begin before 15.9ka. We therefore suggest increasing summer insolation and aridification due to atmospheric circulation changes and perennial sea ice cover as the main mechanisms for the ice thinning and grounded ice retreat from the outer shelves before and during the Heinrich 1 event. The frontal position of the grounded ice sheet, however, did not change during several millennia despite further thinning in interior northern Svalbard. The inner shelf areas rapidly deglaciated towards the fjord mouths along the western coasts between 15 and 14ka and became ice-free before and during meltwater pulse 1a (mwp-1a). The collapse of the ice shelves from the inner shelf towards the fjord mouths and inner fjords occurred on a decadal to centennial time scale based on overlapping radiocarbon ages from marine sediment cores in addition to CN data from erratic boulders in lowlands. We suggest that additional mechanisms must have caused this rapid collapse. Together with reduced moisture supply in the accumulation areas, we assume that subsurface warm Atlantic water masses that reached the western shelf after 17.5ka may have accelerated debuttressing of the ice shelves in addition to the Bølling warming that kicked in around 15.1ka due to increased insolation and the global sea-level rise called mwp-1a. Conservative calculations estimate the contribution of only the northwestern part of the BSIS to sea-level rise with 0.0004cmyr-1 between 26 and 16ka and 0.02cmyr-1 in assumed 300 years between 15 and 14ka. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60552
Appears in Collections: 过去全球变化的重建
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作者单位: University Centre in Svalbard, Department of Arctic Geology, 9171 Longyearbyen, Svalbard, Norway; University of Tromsø, Department of Geology, 9037 Tromsø, Norway
Recommended Citation:
Hormes A.,Gjermundsen E.F.,Rasmussen T.L.. From mountain top to the deep sea - Deglaciation in 4D of the northwestern Barents Sea ice sheet[J]. Quaternary Science Reviews,2013-01-01,75