This award provides 50% funding for the purchase of five Global Positioning System (GPS) receivers whose use in the field will be shared between the Principal Investigator and colleagues at the Massachusetts Institute of Technology and members of the University UNAVSTAR Consortium (UNAVCO). MIT is committed to providing the remaining funds necessary for this acquisition, and the UNAVCO consortium is committed to providing maintenance and repair for the GPS receivers. Since its introduction in the mid-1980s, GPS surveying has become an indispensable tool for the study of present-day regional tectonics. The ability to measure directly, with accuracy of a few millimeters per year, motions of the earth's crust over large distances allows direct observation of lithosphere plate motions, mountain building, and local deformations due to earthquakes and volcanos. The MIT group and the UNAVCO consortium will use the new receivers in a program of field campaigns aimed at a better understanding of present-day crustal deformation processes.