The case for a stable East Antarctic Ice Sheet: the background
The case for a stable East Antarctic Ice Sheet
Antarctica ; Climatic variation ; Glacial features ; Global change ; Ice sheet ; Sea level ; Tectonics ; Volcanism
There are two primary views concerning the stability of the East Antarctic Ice Sheet. After summarising the status of the two hypotheses, the AA. explain the rationale for this volume. Building on the Vega Symposium of April 1993, it presents
the case for the stability of the East Antarctic Ice Sheet and includes new work on terrestrial geomorphology and geology, marine cores and ice-sheet modelling.
Glaciological modelling of the Late Cenozoic East Antarctic ice sheet: stability or dynamism?
The case for a stable East Antarctic Ice Sheet
Antarctica ; Cenozoic ; Climatic variation ; Glacial features ; Glacier mass balance ; Ice sheet ; Model
Two widely different hypotheses have been proposed for the late Tertiary glacial history of East Antarctica. These invoke ice sheet reconstructions ranging from severe glaciation completely burying the Transantarctic Mountains to a situation
, in which an unstable East Antarctic Ice Sheet repeatedly collapses to produce ice-free conditions over interior basins. Experiments were performed with a 3-D model of the Antarctic Ice Sheet to determine the ice sheet geometries to be expected under various
Antarctica ; Cold area ; Glacier dynamics ; Glaciology ; Global change ; Ice sheet ; Model ; Sea level ; Temperature
Although the mechanics and qualitative dynamics of grounded ice sheets and ice shelves are fairly well understood, this is not true for the transition between the two. In consequence, the existence and nature of any grounding line instability have
yet to be established. Further problems are understanding how uncertainties in input parameters affect results, and obtaining optimal techniques for parameter inference using ice-sheet models.
East Antarctic Ice Sheet sensitivity to Pliocene climatic change from a dry valleys perspective
The case for a stable East Antarctic Ice Sheet
Antarctica ; Cenozoic ; Deglaciation ; Glacial features ; Global change ; Ice sheet ; Palaeoclimate ; Pliocene ; Tectonics
The AA. examine the proposition that the East Antartic Ice Sheet collapsed during intervals of excess Pliocene warmth. They start by reviewing the hypothesis of Pliocene deglaciation. This hypothesis yields certain prediction concerning Pliocene
paleoclimate and ice sheet history. Then they test these predictions from an examination of landscape development and surficial sediments in the Dry Valleys sector of the Transantarctic Mountains.
Landsat images reveal a previously unsuspected large-scale pattern of streamlining drift that is assumed to reflect former phases of ice flow. The ice-moulded landform assemblage is described and illustrated with reference to examples from Canada
Implications of the radiocarbon timescale for ice-sheet chronology and sea-level change
C14 dating ; Deglaciation ; Geochronology ; Glaciation ; Global change ; Ice sheet;Ice cap;Inlandsis ; Isostasy ; Model ; Palaeo-environment ; Quaternary ; Sea level
A new extended radiocarbon calibration curve has allowed a reexamination of relative sea-level data based on pre-Holocene dates. At sites locates far from any Late Pleistocene ice sheet, the effect of employing this new calibration curve
is that the calibrated data now agnee with the corresponding relative sea-level curve predicted by the ICE-3G deglaciation model.
This study shows that ice cores contain valuable information of past eruptions, even if the identify of the source volcano or eruption cannot be specified. Such studies may provide important information regarding the link between major volcanic
Landscapes of cold-centred Late Wisconsinan ice caps, Arctic Canada
Arctic Ocean;Arctic Region ; Canada ; Cold area ; Geomorphology ; Glacial features ; Glaciology ; Ice sheet;Ice cap;Inlandsis ; Meltwater ; Model ; Quaternary ; Wisconsinan
Uplands of the Canadian Arctic Islands supported Late Wisconsinan ice caps that developed two landscape zones reflecting basal thermal conditions regulated by long-sustained ice flow patterns. Central cold-based zones protected older glacial
and preglacial landscapes while peripheral warm-based zones scoured and otherwise altered their beds. Some geomorphic effects are independent of ice cap scale, others vary with scale.
Late Tertiary Antarctic paleoclimate and ice-sheet dynamics inferred from surficial deposits in Wright Valley
The case for a stable East Antarctic Ice Sheet
Antarctica ; Cenozoic ; Deglaciation ; Glacial features ; Glacier mass balance ; Ice sheet ; Palaeoclimatology
The evidence of persistent cold paleoclimate contradicts the postulated Pliocene deglaciation of East Antarctica, which requires atmospheric temperatures 20°C warmer than present to produce melting ablation surfaces on the East Antarctic Ice Sheet
. Furthermore, an East Antarctic outlet glacier has not expanded into east-central Wright Valley in at least the last 3.8 Ma, thus precluding ice-sheet overriding of the Dry Valleys region during this interval. Overall, Wright Valley data imply that the adjacent
East Antarctic Ice Sheet has been stable for at least the last 3.8 Ma.
discussed in recent literature in the context of the deforming-bed model have been discussed in earlier literature in the context of the basal ice layer. The potential value of basal-ice work is enormous.
A new conceptual diagram is presented that aids in visualizing glacial processes, their effects and may helps improve the understanding of glacial systems. Subglacial processes and products are emphasized in this paper. Ice, water, and till forming
Ice thickness, ablation, and other glaciological measurements on Upper Fremont Glacier, Wyoming
Glacial ablation ; Glacier ; Glaciology ; Ice core ; Meteorology ; Palaeo-environment ; Temperature ; United States ; Wyoming
research utilizing glacial-ice-core composition to reconstruct paleoenvironmental records. The results of glaciological and meteorological investigations are presented and discussed in this paper.
The 1992 Farrington lecture: drumlin bedforms and related ice-marginal depositional systems in Ireland
The aim of this paper was to identify the range of glacigenic processes which operated during drumlin formation and to erect facies models which describe relationships between drumlin distribution and other ice marginal systems in Ireland. Although
drumlin stratigraphies are complex, they provide insights into Late Devensian ice sheet history which now must be evaluated in terms of rapid environmental change.
The aim of this paper is to produce a detailed geologic record of late Cenozoic glacial and non-glacial sedimentation and paleoclimate change. The Quatermain Mountains are ideal for recording ice-sheet fluctuations and paleoclimate change because
they are adjacent to the East Antarctic Ice Sheet and exhibit a suite of glacial erosional features, semi-arid landforms, and widespread drift and colluvium.
The purpose of this paper is to assess the degree of stability/instability of the East Antarctic Ice Sheet during the Pliocene by dating and mapping surficial deposits in middle Taylor Valley in the Dry Valleys region of southern Victoria Land.
Ice-sheet dynamics and subglacial meltwater regime inferred from form and sedimentology of glaciofluvial systems: Victoria Island, District of Franklin, Northwest Territories
are used to infer the necessary ice-sheet dynamics associated with their formation.
Cold area ; Drainage ; Glaciology ; Greenland ; Hydrology ; Ice ; Proglacial lake ; Rill wash ; Sediment transport
receives water from the northern flanks of the Mitdluagkat glacier. It was clearly demonstrated that the formation of frazil ice and anchor ice caused increased sediment transport, dominating the total load of the proglacial stream during the measuring