Citation

Koketsu K, Kikuchi M. Science 2000; 288(5469): 1237-1239.

Affiliation

Earthquake Research Institute, University of Tokyo, Tokyo 113-0032, Japan. inquiry@taro.eri.u-tokyo.ac.jp

Copyright

(Copyright © 2000, American Association for the Advancement of Science)

DOI

unavailable

PMID

10817997

Abstract

The pattern of ground motion for a magnitude 5.7 earthquake near Tokyo was captured by 384 strong ground motion instruments across the Kanto sedimentary basin and its surroundings. The records allow the visualization of the propagation of long-period ground motion in the basin and show the refraction of surface waves at the basin edge. The refracted wave does not travel directly from the earthquake epicenter, but traverses the basin obliquely to the edge. The surface wave inside the basin propagates more slowly than that outside such that the wavefronts separate from each other, and the refracted wave heals the discrepancy in the speed of advance of the wavefronts inside and outside the basin. The refracted arrival is dominant near the edge of the Kanto basin.

Language: en