Present-day crustal deformation along the Magallanes-Fagnano Fault System in Tierra del Fuego from repeated GPS observations

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • L. Mendoza - , Universidad Nacional de La Plata, National Scientific and Technical Research Council Argentina (CONICET) (Author)
  • R. Perdomo - , Universidad Nacional de La Plata (Author)
  • J.L. Hormaechea - , Universidad Nacional de La Plata (Author)
  • D. Del Cogliano - , Universidad Nacional de La Plata (Author)
  • M. Fritsche - , TUD Dresden University of Technology (Author)
  • A. Richter - , Chair of Geodetic Earth System Research (Author)
  • R. Dietrich - , Chair of Geodetic Earth System Research (Author)

Abstract

The present-day deformation of the earth crust in the Argentine part of Tierra del Fuego main island (southernmost South America) is here investigated based on repeated geodetic GPS observations. The island is traversed by the active transform boundary between the South American and Scotia tectonic plates, represented by the Magallanes-Fagnano fault system. Since 1993 a regional network comprising to date 29 GPS sites has been observed almost every year. The complete set of accumulated observations was processed using the Bernese GPS software and state-of-the-art processing strategies and models. The utilization of homogeneous GPS products resulting from a reprocessing of the global IGS network warrants a stable realization of a global reference frame. For each GPS site 3-D positions and linear velocities with error estimates were obtained. A strain analysis of the horizontal velocity components revealed the zones of major deformation activity. A 30-km-wide deformation belt centred on the main trace of the fault system was identified. This belt is bordered to the north (South America) and south (Scotia) by geodynamically stable zones, which move horizontally with a relative average velocity of 4.4 ± 0.6 (east) and −0.3 ± 0.4 (north) mm a−1. Within the deformation belt a maximum strain rate in the order of 0.25 μstrain per year has been detected. A pronounced change in the deformation style from transtension (east) to transpression (west) is observed. The area of predominating shortening of the crust coincides with a local rotation minimum and relative uplift. Throughout the period covered by the GPS observations the displacements and deformations occurred to be linear with time.

Details

Original languageEnglish
Article number184
Pages (from-to)1009-1022
Number of pages11
JournalGeophysical Journal International
Volume184
Issue number3
Publication statusPublished - 1 Mar 2011
Peer-reviewedYes

External IDs

Scopus 79951580514

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