Rock mechanics and dynamic processes in the crust



During the past four years experimental and theoretical studies of the fracture and flow of rock have provided important new insights into the dynamics of geologic processes in the crust and upper mantle. In addition, intensive new observational studies, particularly along the San Andreas fault in California, have yielded new information on the mechanism of earthquakes and faulting. Of particular interest are: (1) work on the friction characteristics of rock under crustal temperature and pressure conditions and its application to the mechanism of faulting; (2) use of laboratory experiments as scale models of seismicity with applications to earthquake statistics; (3) recognition and measurement of fault creep over extensive portions of the San Andreas fault system; (4) use of geologic, geodetic, and seismic data for the determination of rates of movement and strain accumulation on the San Andreas fault; (5) observations and experiments with earthquake triggering; (6) studies of the creep of rock at high temperatures and pressures.