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Anomalous propagation of Rayleigh waves along Izu‐Mariana Trench
Author(s) -
Kato Mamoru,
Hirahara Kazuro
Publication year - 1992
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/92gl02542
Subject(s) - geology , seismology , rayleigh wave , trench , rayleigh scattering , polarization (electrochemistry) , geophysics , lithosphere , ridge , surface wave , anisotropy , tectonics , physics , optics , layer (electronics) , paleontology , chemistry , organic chemistry
Broad band records of Macquarie Ridge earthquake of May 1989 recorded in Japan show anomalous propagation of Rayleigh wave with frequency of 5 – 25 mHz along the back arc side of the Izu‐Mariana trench. Rayleigh waves at three stations in central Japan show different polarization, that is, while one station shows a normal Rayleigh wave, other two stations, only 290 and 510 km apart, show anomalous polarization with a large deviation from the radial direction and their temporal and gradual change. Possible causes of this anomaly include anisotropy as well as laterally heterogeneous velocity structure of the upper mantle in this active marginal basin region.