ABSTRACT
The relationship between isostatic anomalies and average annual earthquake energy released was investigated. Data were used for the United States, West Indies, East Indies, Japan, Africa, and India. The above areas were subdivided into smaller areas, 5° on the side, and the data for the smaller areas were used to determine a relationship between the variables. Because the data were considerably scattered, an averaging method was used for smoothing. Results of the research indicate that (1) a relationship exists between the average annual earthquake energy released from regions and the isostatic relief (or gradient) of the regions, and (2) the isostatic relief can be used as an index of the strain level of the crust and upper mantle.
Aeromagnetic and gravity profiles of the United States along the 37th parallel--A contribution to the upper mantle project