Reversal of the Direction of Horizontal Velocities Induced by GIA as a Function of Mantle Viscosity

T. H.J. Hermans, W. van der Wal, T. Broerse

Research output: Contribution to journalArticleScientificpeer-review

37 Downloads (Pure)

Abstract

In regions undergoing glacial isostatic adjustment present-day horizontal surface motion is observed to point mostly, but not always, away from the former ice load. To interpret these observations, we investigate the direction of horizontal velocities using glacial isostatic adjustment models. The direction is controlled by the opposing actions of inward mantle flow and outward lithosphere motion. In contrast with the prevailing idea that glacial isostatic adjustment-induced horizontal velocities point outward, we show that velocities can be either outward or inward. Immediately after deglaciation velocities point inward but change direction to outward after a time that is controlled by mantle viscosity. Present-day horizontal velocities point outward for a uniform mantle viscosity below 1020 Pa s and inward for above 1022 Pa s, with a combination of outward and inward in between. Our results help to interpret GPS-observed horizontal velocities in areas with varying mantle viscosity.

Original languageEnglish
Pages (from-to)9597-9604
Number of pages8
JournalGeophysical Research Letters
Volume45
Issue number18
DOIs
Publication statusPublished - 1 Jan 2018

Keywords

  • glacial isostatic adjustment
  • horizontal velocities
  • mantle viscosity
  • reversed direction

Fingerprint Dive into the research topics of 'Reversal of the Direction of Horizontal Velocities Induced by GIA as a Function of Mantle Viscosity'. Together they form a unique fingerprint.

Cite this