HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by ROMANOWICZ, B. Articles by GUILLEMANT, P. Search for Related Content GeoRef GeoRef Citation

An experiment in the retrieval of depth and source mechanism of large earthquakes using very long-period Rayleigh wave data

LABORATOIRE D'ETUDE GÉOPHYSIQUE DE STRUCTURES PROFONDES LABORATOIRE ASSOCIÉ AU C.N.R.S. INSTITUT DE PHYSIQUE DU GLOBE, PARIS CEDEX 05, France

Abstract

The possibility of obtaining an estimate of depth for large earthquakes from low-frequency mantle wave data alone is investigated using moment tensor formalism.

After illustrating the sensitivity to depth of the eigenfunctions in the period range of 160 to 350 sec, we give several examples of application of the two-step inversion procedure proposed earlier for shorter period Rayleigh wave data (Romanowicz, 1982). We find that for earthquakes below a depth of about 50 km, we are able to resolve depth even when a spherically symmetric average Earth model is used for propagation corrections. This is particularly interesting in the case of large subduction zone earthquakes for which an estimate of the vertical extent of faulting can thus be obtained, independently of aftershock studies, in a very fast and simple manner which does not involve any synthetic seismogram calculations or lateral heterogeneity modeling.

For shallower earthquakes, especially those with one steeply dipping nodal plane, the resolution of depth is less precise. Taking lateral heterogeneity into account by using available regionalized phase velocities improves the results marginally. We anticipate that accounting more accurately for the low-order harmonics in the worldwide phase velocity distribution should prove most helpful, since these interfere the most with the theoretical radiation patterns of earthquakes. The determination of depth depends more critically on the source process time, which has to be accounted for especially for horizontally propagating faults.

This article has been cited by other articles:

				W. J. Person Seismological notes--November-December 1993 Bulletin of the Seismological Society of America, October 1, 1994; 84(5): 1687 - 1700. [PDF]

				T. C. WALLACE, A. VELASCO, J. ZHANG, and T. LAY A broadband seismological investigation of the 1989 Loma Prieta, California, earthquake: Evidence for deep slow slip? Bulletin of the Seismological Society of America, October 1, 1991; 81(5): 1622 - 1646. [Abstract] [PDF]

				J. ZHANG and T. LAY Effects of centroid location on determination of earthquake mechanisms using long-period surface waves Bulletin of the Seismological Society of America, October 1, 1990; 80(5): 1205 - 1231. [Abstract] [PDF]

				E. JIMENEZ, M. CARA, and D. ROULAND Focal mechanisms of moderate-size earthquakes from the analysis of single-station three-component surface-wave records Bulletin of the Seismological Society of America, August 1, 1989; 79(4): 955 - 972. [Abstract] [PDF]

				J. TALANDIER and E. A. OKAL An algorithm for automated tsunami warning in French Polynesia based on mantle magnitudes Bulletin of the Seismological Society of America, August 1, 1989; 79(4): 1177 - 1193. [Abstract] [PDF]

				W. BRUSTLE and G. MULLER Stopping phases in seismograms and the spatiotemporal extent of earthquakes Bulletin of the Seismological Society of America, February 1, 1987; 77(1): 47 - 68. [Abstract] [PDF]

				K. SATAKE Effects of station coverage on moment tensor inversion Bulletin of the Seismological Society of America, December 1, 1985; 75(6): 1657 - 1667. [Abstract] [PDF]