Dissipation of Energy Radiated by Earthquakes

Abstract

SUMMARY. - Representing radiated seismic energy as a sum of normal modes<br />we are able to develop approximate equations describing the dissipation of<br />this energy in the earth by solid friction. In particular we calculate total energy<br />radiated and spherically averaged dissipation as a function of depth. In a<br />sample (long period) model study we find that energy density as a function of<br />radius and frequency have simple forms and smooth variations with source<br />depth and mechanism as long as the event's spectrum is dominated by fundamental<br />mode energy. Further, we find that shallow focus events are an order of<br />magnitude more energetic than deeper events for the same moment and that<br />dip slip events are up to a factor of six more energetic than strike slip events for<br />the same moment and depth.