Antarctica's hypsometry and crustal thickness

Implications for the origin of anomalous topography in East Antarctica

J. P. O'Donnell, Andrew Arnold Nyblade

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The hypsometry of Antarctica revealed by BEDMAP2 data is characterised by deglaciated modal elevations of ~ - 450m and ~650 m for West and East Antarctica, respectively, and an East Antarctic plateau that is topographically anomalous by ~400-600 m with respect to global continental modal elevation estimates. Superimposed on the East Antarctic plateau are the Gamburtsev Subglacial Mountains, the Dronning Maud Land Mountains and the Vostok Highlands with modal elevations ~400 m in excess of the East Antarctic mode. To ascertain whether East Antarctica's anomalous topography can be attributed to Airy-type crustal compensation, a continental-scale crustal thickness model was derived from the inversion of GOCO03S satellite gravity data constrained by seismic crustal thickness estimates. The average crustal thickness of East Antarctica is ~40 km (for West Antarctica ~24 km), a value typical of continental shields, and while crustal thicknesses of >50 km locally beneath the Gamburtsev Subglacial Mountains and Dronning Maud Land can account for their differential modal elevation above the plateau, crustal thicknesses elsewhere across East Antarctica offer no suggestion of crustal-level continental-scale support for the broader plateau. Enderby Land, for example, resides on the plateau and is characterised by a modal elevation of ~750 m and crust ~40 km thick, whereas off the plateau in East Antarctica, the Aurora and Wilkes Subglacial Basins have modal elevations of ~. - 50m and ~50 m, respectively, yet similarly thick crust. The lack of crustal support for the elevated broader East Antarctic plateau, coupled with seismic images showing fast upper mantle velocities beneath the plateau, suggest a mid-to-lower mantle source for East Antarctica's anomalous topography.

Original languageEnglish (US)
Pages (from-to)143-155
Number of pages13
JournalEarth and Planetary Science Letters
Volume388
DOIs
StatePublished - Feb 15 2014

Fingerprint

hypsometry
crustal thickness
Antarctic regions
Topography
plateaus
topography
plateau
Gravitation
mountains
Satellites
mountain
crusts
Earth mantle
crust
highlands
Antarctica
aurora
lower mantle
estimates
mantle source

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Cite this

@article{47229b8e50fc4765ab8b246a86d94660,
title = "Antarctica's hypsometry and crustal thickness: Implications for the origin of anomalous topography in East Antarctica",
abstract = "The hypsometry of Antarctica revealed by BEDMAP2 data is characterised by deglaciated modal elevations of ~ - 450m and ~650 m for West and East Antarctica, respectively, and an East Antarctic plateau that is topographically anomalous by ~400-600 m with respect to global continental modal elevation estimates. Superimposed on the East Antarctic plateau are the Gamburtsev Subglacial Mountains, the Dronning Maud Land Mountains and the Vostok Highlands with modal elevations ~400 m in excess of the East Antarctic mode. To ascertain whether East Antarctica's anomalous topography can be attributed to Airy-type crustal compensation, a continental-scale crustal thickness model was derived from the inversion of GOCO03S satellite gravity data constrained by seismic crustal thickness estimates. The average crustal thickness of East Antarctica is ~40 km (for West Antarctica ~24 km), a value typical of continental shields, and while crustal thicknesses of >50 km locally beneath the Gamburtsev Subglacial Mountains and Dronning Maud Land can account for their differential modal elevation above the plateau, crustal thicknesses elsewhere across East Antarctica offer no suggestion of crustal-level continental-scale support for the broader plateau. Enderby Land, for example, resides on the plateau and is characterised by a modal elevation of ~750 m and crust ~40 km thick, whereas off the plateau in East Antarctica, the Aurora and Wilkes Subglacial Basins have modal elevations of ~. - 50m and ~50 m, respectively, yet similarly thick crust. The lack of crustal support for the elevated broader East Antarctic plateau, coupled with seismic images showing fast upper mantle velocities beneath the plateau, suggest a mid-to-lower mantle source for East Antarctica's anomalous topography.",
author = "O'Donnell, {J. P.} and Nyblade, {Andrew Arnold}",
year = "2014",
month = "2",
day = "15",
doi = "10.1016/j.epsl.2013.11.051",
language = "English (US)",
volume = "388",
pages = "143--155",
journal = "Earth and Planetary Science Letters",
issn = "0012-821X",
publisher = "Elsevier",

}

TY - JOUR

T1 - Antarctica's hypsometry and crustal thickness

T2 - Implications for the origin of anomalous topography in East Antarctica

AU - O'Donnell, J. P.

AU - Nyblade, Andrew Arnold

PY - 2014/2/15

Y1 - 2014/2/15

N2 - The hypsometry of Antarctica revealed by BEDMAP2 data is characterised by deglaciated modal elevations of ~ - 450m and ~650 m for West and East Antarctica, respectively, and an East Antarctic plateau that is topographically anomalous by ~400-600 m with respect to global continental modal elevation estimates. Superimposed on the East Antarctic plateau are the Gamburtsev Subglacial Mountains, the Dronning Maud Land Mountains and the Vostok Highlands with modal elevations ~400 m in excess of the East Antarctic mode. To ascertain whether East Antarctica's anomalous topography can be attributed to Airy-type crustal compensation, a continental-scale crustal thickness model was derived from the inversion of GOCO03S satellite gravity data constrained by seismic crustal thickness estimates. The average crustal thickness of East Antarctica is ~40 km (for West Antarctica ~24 km), a value typical of continental shields, and while crustal thicknesses of >50 km locally beneath the Gamburtsev Subglacial Mountains and Dronning Maud Land can account for their differential modal elevation above the plateau, crustal thicknesses elsewhere across East Antarctica offer no suggestion of crustal-level continental-scale support for the broader plateau. Enderby Land, for example, resides on the plateau and is characterised by a modal elevation of ~750 m and crust ~40 km thick, whereas off the plateau in East Antarctica, the Aurora and Wilkes Subglacial Basins have modal elevations of ~. - 50m and ~50 m, respectively, yet similarly thick crust. The lack of crustal support for the elevated broader East Antarctic plateau, coupled with seismic images showing fast upper mantle velocities beneath the plateau, suggest a mid-to-lower mantle source for East Antarctica's anomalous topography.

AB - The hypsometry of Antarctica revealed by BEDMAP2 data is characterised by deglaciated modal elevations of ~ - 450m and ~650 m for West and East Antarctica, respectively, and an East Antarctic plateau that is topographically anomalous by ~400-600 m with respect to global continental modal elevation estimates. Superimposed on the East Antarctic plateau are the Gamburtsev Subglacial Mountains, the Dronning Maud Land Mountains and the Vostok Highlands with modal elevations ~400 m in excess of the East Antarctic mode. To ascertain whether East Antarctica's anomalous topography can be attributed to Airy-type crustal compensation, a continental-scale crustal thickness model was derived from the inversion of GOCO03S satellite gravity data constrained by seismic crustal thickness estimates. The average crustal thickness of East Antarctica is ~40 km (for West Antarctica ~24 km), a value typical of continental shields, and while crustal thicknesses of >50 km locally beneath the Gamburtsev Subglacial Mountains and Dronning Maud Land can account for their differential modal elevation above the plateau, crustal thicknesses elsewhere across East Antarctica offer no suggestion of crustal-level continental-scale support for the broader plateau. Enderby Land, for example, resides on the plateau and is characterised by a modal elevation of ~750 m and crust ~40 km thick, whereas off the plateau in East Antarctica, the Aurora and Wilkes Subglacial Basins have modal elevations of ~. - 50m and ~50 m, respectively, yet similarly thick crust. The lack of crustal support for the elevated broader East Antarctic plateau, coupled with seismic images showing fast upper mantle velocities beneath the plateau, suggest a mid-to-lower mantle source for East Antarctica's anomalous topography.

UR - http://www.scopus.com/inward/record.url?scp=84890752642&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84890752642&partnerID=8YFLogxK

U2 - 10.1016/j.epsl.2013.11.051

DO - 10.1016/j.epsl.2013.11.051

M3 - Article

VL - 388

SP - 143

EP - 155

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

SN - 0012-821X

ER -