Late Quaternary history of Washington Land, North Greenland

Abstract

During the last glacial stage, Washington Land in western North Greenland was probably completely inundated by the Greenland Ice Sheet. The oldest shell dates from raised marine deposits that provide minimum ages for the last deglaciation are 9300 cal. yr BP (northern Washington Land) and 7600 cal. yr BP (SW Washington Land). These dates indicate that Washington Land, which borders the central part of Nares Strait separating Greenland from Ellesmere Island in Canada, did not become free of glacier ice until well into the Holocene. The elevation of the marine limit falls from 110 m a.s.l. in the north to 60 m a.s.l. in the southwest. The recession was followed by readvance of glaciers in the late Holocene, and the youngest shell date from Neoglacial lateral moraines north of Humboldt Gletscher is 600 cal. yr BP. Since the Neoglacial maximum, probably around 100 years ago, glaciers have receded. The Holocene marine assemblages comprise a few southern extralimital records, notably of Chlamys islandica dated to 7300 cal. yr BP. Musk ox and reindeer disappeared from Washington Land recently, perhaps in connection with the cold period that culminated about 100 years ago.

The influence of decadal- to millennial-scale ice mass changes on present-day vertical land motion in Greenland: Implications for the interpretation of GPS observations

“…A recent analysis of ice cores has shown that the ice sheet in northwest Greenland experienced a large elevation decrease during the Holocene, which strongly supports this hypothesis [ Vinther et al , 2009]. It is also worth noting that the Huy2 model is not well constrained in the northwest as the temporal coverage and height precision of the RSL data in this region is poor [ Bennike , 2002; Simpson et al , 2009]. …”

Genus Gadus (Gadidae): Composition, distribution, and evolution of forms

“…After the ancestor cod penetrated into the Northern Pacific, the mega group of the cod finished its forma tion in all three oceans, this group lived 2.5-0.9 mil lion years ago. The final phase of the Pliocene was characterized by the decrease of the temperature in the northern regions (Bennike, 1998;Uriarte, 2011). This promoted forming the conditions favorable for the gla cial periods that were accompanied by the dramatic and rapid decrease of the temperature and appearing of the thousand meter ice sheets that also covered the shelf zone.…”

Early to Late Holocene Surface Exposure Ages From Two Marine‐Terminating Outlet Glaciers in Northwest Greenland

“…This northwestern sector of the ice sheet is therefore vital for modeling the deglaciation patterns of the larger GIS over the past ~20 ka as well as into the future. Our work addresses the lack of chronologic constraint in this sector of the ice sheet (Sinclair et al, ) and builds on limited, previous work on the coast of Washington Land (Figure ), the Canadian coast of Ellesmere Island, and a single ocean core from Nares Strait (Bennike, ; Bennike & Björck, ; Blake, ; England, ; Jennings et al, ; Kelly & Bennike, ; Zreda et al, ).…”