Rapid detection and characterization of large earthquakes using quasi-finite-source Green's functions in continuous moment tensor inversion

Abstract

Large earthquakes along subduction zones have the potential to generate tsunamis along local coasts, as well as traveling far across oceans. By continuously inverting for moment tensors we show that it is possible with a single procedure to automatically detect, locate and determine source parameters of any earthquake, from magnitude 3.5 to larger than 8 located in both the near-and far-field. We find that the detection and characterization of large earthquakes is improved when quasi-finite-source Green's functions are used in a point-source moment tensor approach as they represent to some extent the rupture's finiteness and directivity. Solutions can be obtained within several minutes after the origin time of the earthquake, and could therefore be used as part of a near-source tsunami early warning system, capable of providing tens of minutes of possible warning depending on the distance of the earthquake rupture from the coast. Copyright 2011 by the American Geophysical Union.