scholarly journals Late Wisconsin and Early Holocene Glacial History, Inner Ross Embayment, Antarctica

1989 ◽  
Vol 31 (2) ◽  
pp. 151-182 ◽  
Author(s):  
George H. Denton ◽  
James G. Bockheim ◽  
Scott C. Wilson ◽  
Minze Stuiver
Keyword(s):  
Ross Sea ◽  
Ice Sheet ◽  
Drainage System ◽  
Outlet Glacier ◽  
Radiocarbon Dates ◽  
Terra Nova Bay ◽  
Elevation Changes ◽  
Transantarctic Mountains ◽  
Pass Through ◽  
Basal Melting

AbstractLateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore (Beardmore Glacier), Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and “younger” (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000–13,000 yr B.P. Outlet-glacier profiles from these drifts constrain late Wisconsin ice-sheet surface elevations. Within these constraints, we give two extreme late Wisconsin reconstructions of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice-shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment one reconstruction shows floating shelf ice, whereas the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600-6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains. Sea level and basal melting probably controlled the extent of grounded ice in the Ross Embayment. The interplay between the precipitation (low late Wisconsin and high Holocene values) and the influence of grounding on outlet glaciers (late Wisconsin thickening and late Wisconsin/Holocene thinning, with effects dying out inland) probably controlled minor elevation changes of the polar plateau.

scholarly journals The Cordilleran Ice Sheet in Northern British Colombia

2007 ◽  
Vol 45 (3) ◽  
pp. 355-363 ◽  
Author(s):  
June M. Ryder ◽  
Denny Maynard
Keyword(s):  
Early Phase ◽  
Ice Sheet ◽  
Drainage System ◽  
Ice Flow ◽  
Outlet Glacier ◽  
Radiocarbon Dates ◽  
Coast Mountains ◽  
British Colombia ◽  
Late Wisconsinan ◽  
Cordilleran Ice Sheet

ABSTRACT Dates from lavas associated with tills and erratics indicate that ice-sheet glaciations occurred between 4 and 0.6 Ma BP. The few radiocarbon dates that are available suggest that the chronology of the Late Wisconsinan (Fraser Glaciation) ice sheet of northern British Columbia was similar to that of the southern part of the province. During what may have been a long, early phase of this glaciation, Glacial Lake Stikine was dammed by advancing valley glaciers in the Coast Mountains, and alpine glaciers developed on the intermontane plateau. At the climax of Fraser Glaciation, ice-flow patterns were dominated by outflow from a névé centred over the northern Skeena Mountains. Déglaciation occurred partly by frontal retreat of ice tongues and partly by downwasting of stagnant ice. Recessional moraines mark one or more resurgences or stillstands of the ice margin. During déglaciation, Stikine River valley was occupied by an active outlet glacier and a major subglacial drainage system.

Pre-LGM open-water conditions south of the Drygalski Ice Tongue, Ross Sea, Antarctica

2007 ◽  
Vol 19 (3) ◽  
pp. 373-377 ◽  
Author(s):  
Furio Finocchiaro ◽  
Carlo Baroni ◽  
Ester Colizza ◽  
Roberta Ivaldi
Keyword(s):  
Ross Sea ◽  
Open Water ◽  
Radiocarbon Dates ◽  
The Core ◽  
Bay Area ◽  
Terra Nova Bay ◽  
Insoluble Organic Matter ◽  
Victoria Land ◽  
Marine Isotope Stage 3 ◽  
Raised Beaches

AbstractA marine sediment core collected from the Nordenskjold Basin, to the south of the Drygalski Ice Tongue, provides new sedimentological and chronological data for reconstructing the Pleistocene glacial history and palaeoenvironmental evolution of Victoria Land. The core consists of an over consolidated biogenic mud covered with glacial diamicton; Holocene diatomaceous mud lies on top of the sequence. Radiocarbon dates of the acid insoluble organic matter indicate a pre-Last Glacial Maximum age (>24kyr) for the biogenic mud at the base of the sequence. From this we can presume that at least this portion of the western Ross Sea was deglaciated during Marine Isotope Stage 3 and enjoyed open marine conditions. Our results are consistent with recent findings of pre-Holocene raised beaches at Cape Ross and in the Terra Nova Bay area.

Regional-scale abrupt Mid-Holocene ice sheet thinning in the western Ross Sea, Antarctica

Geology ◽  
2020 ◽  
Author(s):  
R.S. Jones ◽  
R.J. Whitmore ◽  
A.N. Mackintosh ◽  
K.P. Norton ◽  
S.R. Eaves ◽  
...  
Keyword(s):  
Ross Sea ◽  
Numerical Models ◽  
Regional Scale ◽  
Ice Sheet ◽  
Outlet Glacier ◽  
Bed Topography ◽  
Geological Past ◽  
External Driver ◽  
Regional Sea Level ◽  
Western Ross Sea

Outlet glaciers drain the majority of ice flow in the Antarctic ice sheet. Theory and numerical models indicate that local bed topography can play a key role in modulating outlet glacier response to climate warming, potentially resulting in delayed, asynchronous, or enhanced retreat. However, the period of modern observations is too short to assess whether local or regional controls dominate ice sheet response on time scales that are critical for understanding ice sheet mass loss over this century and beyond. The recent geological past allows for insight into such centennial-scale ice sheet behavior. We present a cosmogenic surface-exposure chronology from Mawson Glacier, adjacent to a region of the Ross Sea that underwent dynamic marine-based ice sheet retreat following the Last Glacial Maximum. Our data record at least 220 m of abrupt ice thinning between 7.5 and 4.5 ka, followed by more gradual thinning until the last millennium. The timing, rates, and magnitudes of thinning at Mawson Glacier are remarkably similar to that documented 100 km to the south at Mackay Glacier. Together, both outlet glaciers demonstrate that abrupt deglaciation occurred across a broad region in the Mid-Holocene. This happened despite the complex bed topography of the western Ross Sea and implies an overarching external driver of retreat. When compared to regional sea-level and ocean-temperature changes, our data indicate that ocean warming most likely drove grounding-line retreat and ice drawdown, which then accelerated as a result of marine ice sheet instability.

The local Last Glacial Maximum in McMurdo Sound, Antarctica: Implications for ice-sheet behavior in the Ross Sea Embayment

2019 ◽  
Vol 132 (1-2) ◽  
pp. 31-47 ◽  
Author(s):  
Andrew J. Christ ◽  
Paul R. Bierman
Keyword(s):  
Last Glacial Maximum ◽  
Ross Sea ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
Significant Advance ◽  
Ice Flow ◽  
Mcmurdo Sound ◽  
Last Glacial ◽  
Transantarctic Mountains ◽  
Western Ross Sea

AbstractDuring the Last Glacial Maximum (LGM), a grounded ice sheet filled the Ross Sea Embayment in Antarctica and deposited glacial sediments on volcanic islands and peninsulas in McMurdo Sound and coastal regions of the Transantarctic Mountains. The flow geometry and retreat history of this ice are debated, with contrasting views yielding divergent implications for the interaction between and stability of the East and West Antarctic ice sheets during late Quaternary time. Here, we present terrestrial geomorphologic evidence and reconstruct former ice-marginal environments, ice sheet elevations, and ice-flow directions in McMurdo Sound. Fossil algae in ice-marginal sediments provide a coherent radiocarbon chronology of maximum ice extent and deglaciation. We integrate these data with marine records to reconstruct grounded ice dynamics in McMurdo Sound and the western Ross Sea. The combined data set suggests ice flow toward the Transantarctic Mountains in McMurdo Sound during peak glaciation, with thick, grounded ice at or near its maximum position between 19.6 and 12.3 ka. Persistent grounded ice in McMurdo Sound and across the western Ross Sea after Meltwater Pulse 1a (14.0–14.5 ka) suggests that this sector of Antarctica did not significantly contribute to this rapid sea-level rise event. Our data show no significant advance of locally derived ice from the Transantarctic Mountains into McMurdo Sound during the local LGM.

Cenozoic Glacial and Tectonic History of the Transantarctic Mountains in the McMurdo Sound Region: Recent Progress from Drilling and Related Studies

Polar Record ◽  
1981 ◽  
Vol 20 (129) ◽  
pp. 543-548 ◽  
Author(s):  
P. J. Barrett ◽  
B. C. McKelvey
Keyword(s):  
Ross Sea ◽  
Ice Sheet ◽  
Ice Cover ◽  
Early History ◽  
Antarctic Ice Sheet ◽  
Ice Cap ◽  
Tectonic History ◽  
History Of ◽  
Transantarctic Mountains ◽  
East Antarctic Ice Sheet

Two of the outstanding problems in Antarctic earth sciences are the early history of the East Antarctic ice sheet, and the history of the Transantarctic Mountains. These two problems may well be linked, for if the initial uplift of the Transantarctic Mountains was sufficient to promote a permanent ice cap, this may have triggered formation of the East Antarctic ice sheet in the manner oudined by Drewry (1975, p 266). Glomar Challenger in 1973 made the first major breakthrough concerning early history of the ice sheet by recovering cores from the centre of the Ross Sea; they show that ice rafting began there 25 Ma BP and has been going on ever since (Hayes and others, 1975). However, the core data give little indication of the extent of ice cover, or of the climatic changes that led to expanded ice cover which produced the ice-rafted debris.

scholarly journals 20th century behaviour of Drygalski Ice Tongue, Ross Sea, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 397-400 ◽  
Author(s):  
M. Frezzotti ◽  
M.C.G Mabin
Keyword(s):  
Sea Ice ◽  
20Th Century ◽  
Ross Sea ◽  
Early Years ◽  
Aerial Photographs ◽  
Significant Feature ◽  
Outlet Glacier ◽  
Terra Nova Bay ◽  
Ice Production ◽  
Sea Area

Drygalski Ice Tongue is the floating seaward extension of David Glacier, a large outlet glacier draining from Talos and Circe Domes of the East Antarctic ice sheet. Several explorers mapped and described Drygalski Ice Tongue in the early years of the 20th century and, although this information does not allow detailed interpretation of ice-tongue behaviour, it is clear that from 1900–12 it was a significant feature extending 65—75 km from the coast. More detailed information has been compiled from aerial photographs and satellite images. In December 1956, the ice tongue was about 110 km long. By December 1957, a major calving event had occurred and the outer 40 km of the ice tongue had broken away. This is the only major 20th century calving event identified, and it may have occurred during a violent storm that affected the Ross Sea area in mid-June 1957. By 1960, further minor ice loss had occurred but, since that time, Drygalski Ice Tongue has maintained the same shape. In January 1993, the ice tongue was 95.8 km long and at its terminus was flowing at 880 900 m a-1. Drygalski Ice Tongue is an important regulator of the size of the Terra Nova Bay polynya. The average size of the Polynya has varied from nearly 2000 km2, in 1956, to 650 km2in 1957. This has a. significant impact on sea-ice production in the Ross Sea. In 1956, about 115 km3,) of sea ice would have been produced, sufficient to cover 30%of the Ross Sea area with a 1 m thickness of sea ice.

Delayed maximum and recession of an East Antarctic outlet glacier

Geology ◽  
2020 ◽  
Vol 48 (6) ◽  
pp. 630-634
Author(s):  
Courtney King ◽  
Brenda Hall ◽  
Trevor Hillebrand ◽  
John Stone
Keyword(s):  
Ross Sea ◽  
Ice Sheet ◽  
Outlet Glacier ◽  
Broad Agreement ◽  
Last Glaciation ◽  
Radiocarbon Data ◽  
Global Sea Level ◽  
The Antarctic ◽  
Exposure Ages ◽  
Terrestrial Data

Abstract During the last glaciation, East Antarctic outlet glaciers contributed to a grounded ice sheet in the Ross Embayment. The timing of maximum ice extent, as well as of subsequent deglaciation of these outlets, has implications for the behavior of the Antarctic Ice Sheet (AIS) and its impact on global sea level. We present 45 radiocarbon ages of lacustrine cyanobacteria from the Lake Wellman region alongside Hatherton Glacier, which are the first terrestrial data to both record advance of an Antarctic glacier to its maximum position as well as document a high-resolution chronology of subsequent retreat. Seventeen new exposure ages are widely scattered, but the youngest four are in broad agreement with the radiocarbon data. Hatherton Glacier slowly thickened from 13,000 to 9500 yr B.P. and then thinned steadily until at least ca. 2800 yr B.P. Our work affords evidence of both a delayed maximum and recession of an East Antarctic outlet glacier compared to the global Last Glacial Maximum (LGM) and supports growing evidence of a time-transgressive local LGM within the Ross Sea sector of the ice sheet. Both observations are consistent with the idea that the timing of outlet glacier expansion and timing of recession are controlled by the balance between dynamic thinning from ocean forcing and increased accumulation due to atmospheric warming.

scholarly journals Outlet glacier and margin elevation changes: Near-coastal thinning of the Greenland ice sheet

2001 ◽  
Vol 106 (D24) ◽  
pp. 33729-33741 ◽  
Author(s):  
W. Abdalati ◽  
W. Krabill ◽  
E. Frederick ◽  
S. Manizade ◽  
C. Martin ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Outlet Glacier ◽  
Elevation Changes

scholarly journals Holocene thinning of Darwin and Hatherton glaciers, Antarctica, and implications for grounding-line retreat in the Ross Sea

2021 ◽  
Vol 15 (7) ◽  
pp. 3329-3354
Author(s):  
Trevor R. Hillebrand ◽  
John O. Stone ◽  
Michelle Koutnik ◽  
Courtney King ◽  
Howard Conway ◽  
...  
Keyword(s):  
Catchment Area ◽  
Ross Sea ◽  
Three Dimensional ◽  
Ice Sheet ◽  
Early Holocene ◽  
Last Deglaciation ◽  
Grounding Line ◽  
The Last Deglaciation ◽  
Transantarctic Mountains ◽  
Exposure Ages

Abstract. Chronologies of glacier deposits in the Transantarctic Mountains provide important constraints on grounding-line retreat during the last deglaciation in the Ross Sea. However, between Beardmore Glacier and Ross Island – a distance of some 600 km – the existing chronologies are generally sparse and far from the modern grounding line, leaving the past dynamics of this vast region largely unconstrained. We present exposure ages of glacial deposits at three locations alongside the Darwin–Hatherton Glacier System – including within 10 km of the modern grounding line – that record several hundred meters of Late Pleistocene to Early Holocene thickening relative to present. As the ice sheet grounding line in the Ross Sea retreated, Hatherton Glacier thinned steadily from about 9 until about 3 ka. Our data are equivocal about the maximum thickness and Mid-Holocene to Early Holocene history at the mouth of Darwin Glacier, allowing for two conflicting deglaciation scenarios: (1) ∼500 m of thinning from 9 to 3 ka, similar to Hatherton Glacier, or (2) ∼950 m of thinning, with a rapid pulse of ∼600 m thinning at around 5 ka. We test these two scenarios using a 1.5-dimensional flowband model, forced by ice thickness changes at the mouth of Darwin Glacier and evaluated by fit to the chronology of deposits at Hatherton Glacier. The constraints from Hatherton Glacier are consistent with the interpretation that the mouth of Darwin Glacier thinned steadily by ∼500 m from 9 to 3 ka. Rapid pulses of thinning at the mouth of Darwin Glacier are ruled out by the data at Hatherton Glacier. This contrasts with some of the available records from the mouths of other outlet glaciers in the Transantarctic Mountains, many of which thinned by hundreds of meters over roughly a 1000-year period in the Early Holocene. The deglaciation histories of Darwin and Hatherton glaciers are best matched by a steady decrease in catchment area through the Holocene, suggesting that Byrd and/or Mulock glaciers may have captured roughly half of the catchment area of Darwin and Hatherton glaciers during the last deglaciation. An ensemble of three-dimensional ice sheet model simulations suggest that Darwin and Hatherton glaciers are strongly buttressed by convergent flow with ice from neighboring Byrd and Mulock glaciers, and by lateral drag past Minna Bluff, which could have led to a pattern of retreat distinct from other glaciers throughout the Transantarctic Mountains.

scholarly journals 20th century behaviour of Drygalski Ice Tongue, Ross Sea, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 397-400 ◽  
Author(s):  
M. Frezzotti ◽  
M.C.G Mabin
Keyword(s):  
Sea Ice ◽  
20Th Century ◽  
Ross Sea ◽  
Early Years ◽  
Aerial Photographs ◽  
Significant Feature ◽  
Outlet Glacier ◽  
Terra Nova Bay ◽  
Ice Production ◽  
Sea Area

Drygalski Ice Tongue is the floating seaward extension of David Glacier, a large outlet glacier draining from Talos and Circe Domes of the East Antarctic ice sheet. Several explorers mapped and described Drygalski Ice Tongue in the early years of the 20th century and, although this information does not allow detailed interpretation of ice-tongue behaviour, it is clear that from 1900–12 it was a significant feature extending 65—75 km from the coast. More detailed information has been compiled from aerial photographs and satellite images. In December 1956, the ice tongue was about 110 km long. By December 1957, a major calving event had occurred and the outer 40 km of the ice tongue had broken away. This is the only major 20th century calving event identified, and it may have occurred during a violent storm that affected the Ross Sea area in mid-June 1957. By 1960, further minor ice loss had occurred but, since that time, Drygalski Ice Tongue has maintained the same shape. In January 1993, the ice tongue was 95.8 km long and at its terminus was flowing at 880 900 m a-1. Drygalski Ice Tongue is an important regulator of the size of the Terra Nova Bay polynya. The average size of the Polynya has varied from nearly 2000 km2, in 1956, to 650 km2 in 1957. This has a. significant impact on sea-ice production in the Ross Sea. In 1956, about 115 km3,) of sea ice would have been produced, sufficient to cover 30%of the Ross Sea area with a 1 m thickness of sea ice.

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