Geodetic determination of relative plate motion and crustal deformation across the Scotia-South America plate boundary in eastern Tierra del Fuego

• Published in: Geochemistry, Geophysics, Geosystems
• Main Authors: Smalley, R., Kendrick, E., Bevis, M. G., Dalziel, I. W.D., Taylor, F., Lauría, E., Barriga, R., Casassa, G.
• Format: Text
• Language: unknown
• Published: University of Memphis Digital Commons 2003
• Subjects: Crustal deformation; Plate movement; Scotia arc; South America; Geophysics and Seismology; Magallanes; Patagonia; Antarc*; Antarctica; Tierra del Fuego
• Online Access: https://digitalcommons.memphis.edu/facpubs/1477; https://doi.org/10.1029/2002GC000446

Global Positioning System (GPS) measurements provide the first direct measurement of plate motion and crustal deformation across the Scotia-South America transform plate boundary in Tierra del Fuego. This plate boundary accommodates a part of the overall motion between South America and Antarctica. The subaerial section of the plate boundary in Tierra del Fuego, about 160 km in length, is modeled as a two dimensional, strike-slip plate boundary with east-west strike. Along the Magallanes-Fagnano fault system, the principal fault of this portion of the plate boundary, relative plate motion is left-lateral strikeslip on a vertical fault at 6.6 ± 1.3 mm/year based on an assumed locking depth of 15 km. The site velocities on the Scotia Plate side are faster than the relative velocity by an additional 1-2 mm/yr, suggesting there may be a wider region of diffuse left-lateral deformation in southern Patagonia. The northsouth components of the velocities, however, do not support the existence of active, large-scale transpression or transtension between the South America and Scotia plates along this section of the plate boundary. © 2003 by the American Geophysical Union.