INTERNAL FRICTION IN TERRESTRIAL ROCKS AT HIGH PRESSURES

ABSTRACT Recent experimental investigations show that in the seismic Q profiles for certain parts of the earth's crust there is a range of Q values from several hundred at small depths to well over 1000 at depths greater than 15 km. Experimental investigations were conducted in our laboratory on the internal friction in wet and vacuum dried olivine basalts over a pressure range from 0 to 1 kbar. The results tend to support the view that the Q variation is due to processes involving various states of H 2 O in pores and cracks.