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Titolo:
The response of the East Antarctic ice-sheet to the evolving tectonic configuration of the Transantarctic Mountains
Autore:
Kerr, A; Huybrechts, P;
Indirizzi:
Univ Edinburgh, CECS, Edinburgh EH9 3JK, Midlothian, Scotland Univ Edinburgh Edinburgh Midlothian Scotland EH9 3JK Midlothian, Scotland Free Univ Brussels, Geograf Inst, B-1050 Brussels, Belgium Free Univ Brussels Brussels Belgium B-1050 nst, B-1050 Brussels, Belgium
Titolo Testata:
GLOBAL AND PLANETARY CHANGE
fascicolo: 1-4, volume: 23, anno: 1999,
pagine: 213 - 229
SICI:
0921-8181(199912)23:1-4<213:TROTEA>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
SOUTHERN VICTORIA-LAND; RIFT SYSTEM; DRY VALLEYS; UPLIFT; CONSTRAINTS; ESCARPMENT; EVOLUTION; BOUNDARY; GLACIER;
Keywords:
Antarctica; Cenozoic; ice-sheet; glacial; tectonic; paleotopography;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
31
Recensione:
Indirizzi per estratti:
Indirizzo: Kerr, A Univ Edinburgh, CECS, John Muir Bldg,Kings Bldg, Edinburgh EH9 3JK, Midlothian, Scotland Univ Edinburgh John Muir Bldg,Kings Bldg Edinburgh Midlothian Scotland EH9 3JK
Citazione:
A. Kerr e P. Huybrechts, "The response of the East Antarctic ice-sheet to the evolving tectonic configuration of the Transantarctic Mountains", GLOBAL PLAN, 23(1-4), 1999, pp. 213-229

Abstract

The landscape of the Transantarctic Mountains is the result of the coupledevolution of the West Antarctic rift system and the East Antarctic ice-sheet. Studies of this glacial-tectonic system generally assume that the evolving surface elevation of the Transantarctic Mountains is a key determinant of the changing East Antarctic ice-sheet dynamics between the Miocene and today. Hen, we extend previous work [Huybrechts. Ph., 1993. Glaciological modelling of the Late Cenozoic East Antarctic ice-sheet: stability or dynamism? Geografiska Annaler Stockholm, 75A (4) 221-238.] by using numerical models of the ice-sheet and lithosphere to examine the impact of different bedrock surface elevations of the Transantarctic Mountains on ice-sheet dynamics, There are widely different interpretations of the evolution of the Transantarctic Mountains from the available data, so we explore bedrock surface elevations suggested by empirical evidence in recent papers about the sensitivity of the Late Cenozoic ice-sheet. The results show that the surface elevation of individual mountain blocks has only a very local effect on ice-sheet dynamics. The existing mountain blocks of the Transantarctic Mountains, which force inland ice to drain through troughs adjacent to the mountain blocks, were overriden by inland ice when bedrock elevations were 1 km lower. When the troughs through the mountains were less well developed, in the Pliocene or Miocene, inland ice was thicker and ice-surface gradients and ice-velocities across the mountains were higher. This led to more active and erosive outlet glaciers through the mountains and the further development of these troughs. From these results, the key determinant of East Antarctic ice dynamics appears to be the interplay between the development of major troughs through the Transantarctic Mountains and rising mountain elevations. The glacial history of the central Transantarctic Mountain ranges was verydifferent to that of more peripheral mountain ranges, such as the Dry Valleys and Victoria Land. The development of independent ice centres in the latter regions and the overriding of these ice centres by the main ice-sheet is very sensitive to the timing of surface uplift and the particular climate profile of the period. Conversely, the ice-surface profile across the central ranges is similar under widely different climates. The limitations of such a study stem from the necessarily schematic bedrock elevations input to the model and simplifications within the models. At present, insufficiently detailed modelling of the impact of troughs on ice-sheet dynamics means this paper is necessarily speculative, However, this work points to the importance of the outlet troughs on ice-sheet dynamics, rather than simply therising surface elevations of the Transantarctic Mountains along the rift margin upwarp. (C) 1999 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/10/20 alle ore 10:05:38