B. Chouet
J. Almendros
2003
<p><span>We investigate the </span>performance<span> of a source </span>location<span> </span>method<span> that combines multichannel </span>semblance<span> and particle motions and is being increasingly used to obtain estimates of the source locations of very </span>long<span> </span>period<span> (VLP) seismic </span>signals<span> recorded on volcanoes. The </span>method<span> makes use of the </span>radial<span> particle motions and large wavelengths that characterize the VLP events. To assess the capabilities of this </span>radial<span> </span>semblance<span> </span>method<span>, and to better understand its limitations, we quantify the effects of window length, noise contents of the </span>signal<span>, inaccurate velocity models, receiver coverage, and orientation errors in the horizontal components of the receivers. Our results show that the </span>semblance<span> </span>method<span> performs best when (1) the noise level is low enough to allow a good characterization of the waveforms, (2) the sources are located at distances between one half of the average receiver spacing and about two times the network aperture, and (3) the orientations of the horizontal components of the seismometers are known with relative accuracy. When these requirements are met, the </span>radial<span> </span>semblance<span> </span>method<span> constitutes an adequate tool to obtain preliminary locations of VLP </span>volcanic<span> </span>signals<span> recorded by broadband networks. Moreover, we provide a formula to determine the </span>radial<span> </span>semblance<span> level that should be used to define error regions associated to the estimated source locations.</span></p>
application/pdf
10.1785/0120020143
en
Seismological Society of America
Performance of the radial semblance method for the location of very long period volcanic signals
article