Block modeling of crustal deformation in Tierra del Fuego from GNSS velocities

L. MENDOZA; A. RICHTER; M. FRITSCHE; J. L. HORMAECHEA; M. HORWATH; R. PERDOMO; R. DIETRICH

Praga

Congreso; 26th IUGG General Assembly; 2015

International Union of Geodesy and Geophysics

The Tierra del Fuego (TDF) main island is divided by a major transformboundary between the South America and Scotia tectonic plates. Using ablock model, we infer slip rates, locking depths and inclinations of activefaults in TDF from inversion of site velocities derived from GlobalNavigation Satellite System (GNSS) observations. We use interseismicvelocities from 48 sites, obtained from field measurements spanning 20years. Euler vectors consistent with a simple seismic cycle are estimatedfor each block. In addition, we introduce far-field information into themodeling by applying constraints on Euler vectors of major tectonic plates. An average strike-slip rate of 5.8 +/- 0.2 mm/yr was determined inagreement with published geodetic and geophysical estimates for thistectonic boundary. Our results indicate dislocations dipping 66 +/- 6degrees southward, locked to a depth of 10 km, which are consistent with geological models for the MFS. Normal slip also dominates the secondary sense of motion throughout the eastern MFS, with a maximum rate along the Fagnano Lake.