Reciprocity theorem applied to the geophone-ground coupling problem

Abstract Over the last 40 years the problem of geophone coupling has received regular attention. The problem of geophone coupling is the difference between the velocity as measured by the geophone and the velocity of the ground without the geophone. The papers published on this subject are based either on experimental work or on theoretical considerations. Washburn and Wiley (1941) show the remarkable differences between records from geophones laid on the surface and geophones placed on wooden posts driven about 1 ft into the ground. Similar observations were made by other experimentalists such as Fail et al. (1962), Hoover and O'Brien (1980), Omata (1983), and Krohn (1984).