Abstract: | Yearly seismic energy totals for many different regions of the earth show highs in 1965 and lows in 1967. Correlations found between totals for ridge systems and for the world are attributed to ambient stresses, which are close to those needed for failure in the lithosphere underlying those ridge systems. Energy highs for many different plate edges are thought to be the result of triggering by the large Alaskan earthquake of 1964. Other suggestions of triggering by major earthquakes are found in 1969 and 1971. |