PORE PRESSURE EFFECTS IN CRUSTAL PROCESSES

Perhaps one of the most significant aspects of the earth's crust is that the cracks and cavities within the rocks are not dry. The presence of interstitial water and water vapor has a pronounced effect on many crack related properties of brittle rocks such as fracture strength, frictional strength, creep rate, static fatigue, seismic wave velocity, compressibility, resistivity, to name a few. Although the influence of water on geophysical properties has been known for many years, several recent developments have accentuated the need for more detailed information on the mechanical and chemical effects of pore water in natural situations. First, the energy crisis has focused attention on the development of new geothermal resources as well as the stability of various rock types in areas proposed for nuclear waste disposal. This paper is not subject to U.S. copyright. Published in 1979 by the American Geophysical Union.