Earthquake intensity anomalies and magma chambers of Azorean volcanoes

A procedure for finding a theoretical earthquake intensity is proposed, and the anomaly is defined as the difference between observed and theoretical intensities. Interpretation of the anomalies is discussed. Application of the method to an Azorean earthquake shows conspicuous negative anomalies, which appear to indicate the probable emplacement of magma chambers of the volcanic system formed by Fayal and Pico Islands.