DOI: 10.1016/j.quascirev.2013.08.020
Scopus记录号: 2-s2.0-84907594798
论文题名: Ross Sea paleo-ice sheet drainage and deglacial history during and since the LGM
作者: Anderson J.B. ; Conway H. ; Bart P.J. ; Witus A.E. ; Greenwood S.L. ; McKay R.M. ; Hall B.L. ; Ackert R.P. ; Licht K. ; Jakobsson M. ; Stone J.O.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 100 起始页码: 31
结束页码: 54
语种: 英语
英文关键词: Glacial history
; LGM-post LGM
; Paleodrainage
; Ross Sea
Scopus关键词: Catchments
; Glacial geology
; Glaciers
; Landforms
; Sea level
; Sediments
; Submarine geology
; Alternative hypothesis
; Glacial history
; Last Glacial Maximum
; LGM-post LGM
; Mid to late Holocene
; Outer continental shelves
; Paleodrainage
; Ross Sea
; Ice
; continental shelf
; deglaciation
; drainage
; geomorphology
; glacial history
; grounding line
; ice retreat
; ice sheet
; Last Glacial Maximum
; marine sediment
; till
; Antarctica
; Ross Sea
; Southern Ocean
英文摘要: Onshore and offshore studies show that an expanded, grounded ice sheet occupied the Ross Sea Embayment during the Last Glacial Maximum (LGM). Results from studies of till provenance and the orientation of geomorphic features on the continental shelf show that more than half of the grounded ice sheet consisted of East Antarctic ice flowing through Transantarctic Mountain (TAM) outlet glaciers; the remainder came from West Antarctica. Terrestrial data indicate little or no thickening in the upper catchment regions in both West and East Antarctica during the LGM. In contrast, evidence from the mouths of the southern and central TAM outlet glaciers indicate surface elevations between 1000m and 1100m (above present-day sea level). Farther north along the western margin of the Ross Ice Sheet, surface elevations reached 720m on Ross Island, and 400m at Terra Nova Bay. Evidence from Marie Byrd Land at the eastern margin of the ice sheet indicates that the elevation near the present-day grounding line was more than 800masl, while at Siple Dome in the central Ross Embayment, the surface elevation was about 950masl. Farther north, evidence that the ice sheet was grounded on the middle and the outer continental shelf during the LGM implies that surface elevations had to be at least 100m above the LGM sea level. The apparent low surface profile and implied low basal shear stress in the central and eastern embayment suggests that although the ice streams may have slowed during the LGM, they remained active. Ice-sheet retreat from the western Ross Embayment during the Holocene is constrained by marine and terrestrial data. Ages from marine sediments suggest that the grounding line had retreated from its LGM outer shelf location only a few tens of kilometer to a location south of Coulman Island by ~13ka BP. The ice sheet margin was located in the vicinity of the Drygalski Ice Tongue by ~11ka BP, just north of Ross Island by ~7.8ka BP, and near Hatherton Glacier by ~6.8ka BP. Farther south, 10Be exposure ages from glacial erratics on nunataks near the mouths of Reedy, Scott and Beardmore Glaciers indicate thinning during the mid to late Holocene, but the grounding line did not reach its present position until 2 to 3ka BP. Marine dates, which are almost exclusively Acid Insoluble Organic (AIO) dates, are consistently older than those derived from terrestrial data. However, even these ages indicate that the ice sheet experienced significant retreat after ~13ka BP. Geomorphic features indicate that during the final stages of ice sheet retreat ice flowing through the TAM remained grounded on the shallow western margin of Ross Sea. The timing of retreat from the central Ross Sea remains unresolved; the simplest reconstruction is to assume that the grounding line here started to retreat from the continental shelf more or less in step with the retreat from the western and eastern sectors. An alternative hypothesis, which relies on the validity of radiocarbon ages from marine sediments, is that grounded ice had retreated from the outer continental shelf prior to the LGM. More reliable ages from marine sediments in the central Ross Embayment are needed to test and validate this hypothesis. © 2014 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60175
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth Sciences, Rice University, 6100 Main Street, Houston, TX, United States; Department of Earth and Space Sciences, University of Washington, 4000 15th Avenue NE, Seattle, WA, United States; Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, United States; Department of Geological Sciences, Stockholm University, Stockholm, Sweden; Antarctic Research Centre, Victoria University of Wellington, P.O. Box 600, New Zealand; School of Earth and Climate Sciences, University of Maine, Orono, ME, United States; Climate Change Institute, University of Maine, Orono, ME, United States; Department of Earth and Planetary Science, Harvard University, Cambridge, MA, United States; Department of Earth Sciences, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, SL118, Indianapolis IN, United States
Recommended Citation:
Anderson J.B.,Conway H.,Bart P.J.,et al. Ross Sea paleo-ice sheet drainage and deglacial history during and since the LGM[J]. Quaternary Science Reviews,2014-01-01,100