Skip to Main content Skip to Navigation
Journal articles

Fast and partitioned postglacial rebound of southwestern Iceland

Abstract : Located both on the Mid-Atlantic Ridge and above a mantle plume, Iceland is subject to horizontal and vertical motions. Many studies described these deformations in terms of rifting episodes that have combined both extensional tectonics and magmatism. However, few studies have described the glacio-isostatic response induced by the retreat of the Weichselian ice cap. The melting of this ice cap induced a postglacial rebound for the whole of Iceland that may be controlled by the geodynamic setting and the rheological layering of the lithosphere. This study is devoted to (1) understanding the Holocene rebound on the southwestern coast and (2) estimating the asthenosphere viscosity and depth beneath Iceland. Two stages of holocene evolution were determined by means of GPS profiles, morphological observations, and data compilation. The first stage corresponds to a vertical uplift of 67.5 to 157.5 m. It started at 10,000 years BP and ended at 8500 years BP implying uplift rates between 4.5 and 10.5 cm/a. It was a quick isostatic response to the fast ice retreat. The second stage had vertical motion of tens of meters with a probable tectonic origin and started at 8500 years BP. The uplift rate is 1 to 2 orders of magnitude slower than the one during the first stage. Uplift partitioning during the first stage was controlled by the thermal state of the lithosphere, the highest geothermal flux inducing the maximum uplift rates. The relaxation time for uplift provides a viscosity estimate of 5.4­5.8 — 1019 Pa s for the asthenosphere. This value is similar to those determined for glacial areas in different continental contexts. However, the flexural wavelength indicates a shallower asthenosphere than that occurring in continental domains. Therefore this study highlights a coupling between the thermal structure of the Icelandic asthenosphere and the glacial rebound.
Document type :
Journal articles
Complete list of metadatas

Cited literature [77 references]  Display  Hide  Download

https://hal-insu.archives-ouvertes.fr/insu-00286999
Contributor : Isabelle Dubigeon <>
Submitted on : Wednesday, June 29, 2016 - 1:57:12 PM
Last modification on : Friday, April 5, 2019 - 8:11:11 PM
Long-term archiving on: : Friday, September 30, 2016 - 11:33:17 AM

File

Biessy_et_al-2008-Tectonics.pd...
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Guillaume Biessy, Olivier Dauteuil, Brigitte van Vliet-Lanoë, A. Wayolle. Fast and partitioned postglacial rebound of southwestern Iceland. Tectonics, American Geophysical Union (AGU), 2008, 27 (3), pp.TC3002. ⟨10.1029/2007TC002177⟩. ⟨insu-00286999⟩

Share

Metrics

Record views

266

Files downloads

337