HR: 1340h
AN: S23A-1103    [Abstracts]
TI: A Year of Microseisms in Southern California
AU: * Gerstoft, P
EM: gerstoft@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman, La Jolla, ca 92093, United States
AU: Tanimoto, T
AF: Department of Earth Science, University of California, Santa Barbara, Department of Earth Science, Santa Barbara, ca 93106, United States
AB: Microseisms are due to continuous harmonic forcing by ocean waves, whose sources vary in time, frequency, and azimuth. Using frequency-domain array beamforming, this variation is studied using one-year of continuous seismic data from 155 stations in Southern California. Detailed analysis of data delineates spatiotemporal variations of sources for the primary and secondary microseisms. Both types of microseisms are generated near the coasts but the locations of excitation are different and change with season. Often sources are multiply located but can be spread out over wider areas, especially in the case of secondary microseisms. Distant storms can also be seen occasionally in the frequency range between the primary and secondary microseisms where spectral amplitudes from nearby sources are low.
UR: http://www.mpl.ucsd.edu/people/gerstoft/
DE: 7200 SEISMOLOGY
SC: Seismology [S]
MN: 2007 Fall Meeting