THE CURRENT DISTRIBUTION OF DEFORMATION IN THE WESTERN TIEN SHAN FROM BLOCK MODELS CONSTRAINED BY GEODETIC DATA

Abstract

We interpret Global Positioning System measurements of interseismic deformation throughout the western Tien Shan in the context of a block model which accounts for important geologic features (faults) and physical processes (elastic strain accumulation.) Through this analysis we are able to quantify the amount of deformation localized on active structures. In the central part of the belt the Dzhuanaryk fault zone appears to be the most important thrust fault, accommodating nearly five millimeters per year of north-south shortening across it. Conversely, the most widely recognized strike-slip fault in the region, the Talas-Fergana, is found to have very little of the previously estimated right lateral motion.