Time reversal imaging of synthetic volcanic tremor sources

Abstract

Time reversal of Scismic wavefields recorded at active volcanoes may provide images of the source process for long-period (LP) or volcanic tremor events directly, independent of assumptions about extent, geometry and mechanics of the source. Time reversal methods involve propagating the original time series from many receiver locations back into the medium. The reversed signals then focus at their origin due to constructive interference, elucidating the source location, extent and radiation pattern. In practice, focusing may be blurred due to inaccurate Earth models or sparse sampling of the wavefield at the surface. Here, we investigate the feasibility of this method for several synthetic volcanic tremor sources and present a gallery of time reversal source images. Wave propagation is computed numerically in a 2D volcano model with realistic topography. Our results indicate that time reversal may be applicable in volcanic settings, possibly yielding new insights into volcanoseismic LP or tremor sources. Copyright 2009 by the American Geophysical Union.