BRITTLE PHENOMENA

The term “brittle phenomena” includes a number of processes that are dominated by fracture as a mechanism or are controlled by the presence of preexisting fractures. Brittle phenomena in rocks are the most pervasive processes in the shallow crust of the Earth influencing natural deformation and controlling man's attempt to utilize natural resources. In particular, brittle phenomena affect: (1) the production of hydrocarbons, which requires a knowledge of the properties of fractured rocks in reservoirs and boreholes and an understanding of hydrofracturing; (2) mining techniques which involve rock removal, underground stability, water flow, and safety; (3) earthquake prediction, which depends upon a knowledge of the mechanical properties in and adjacent to natural fault zones; (4) engineering site evaluation and utilization; (5) waste disposal of radioactive materials, which is contingent not only upon the brittle response of the rock, but upon fluid transport through the material. It is clear that it is not just the brittle response of the rocks, but how fractures influence fluid flow, geophysical measurements, and associated phenomena that makes this an important area of scientific research today. Copyright 1979 by the American Geophysical Union.