|Reporter:||山田 伸之 [Nobuyuki YAMADA]|
K. B. Olsen, S. M. Day, and C. R. Bradley (2003) |
Estimation of Q for Long-Period (>2 sec) Waves in the Los Angeles Basin,
Bull. Seism. Soc. Am., 93, 627-638.
|Summary:||They simulated long-period (>2 sec) 3D wave propagation through the Southern California Earthquake Center seismic velocity reference model, version 2, for the 1994 Northridge earthquake in order to examine the effects of anelastic attenuation. They used FD staggered-grid method with the coarse-grained frequency-independent anelastic scheme of Day and Bradley (2001). They preferred Q model is Qs/Vs=0.02 for Vs less than 1000-2000m/s, and Qs/Vs=0.1 for layers with higher velocities. The anelastic losses have the largest effect on short-period surface waves propagating in the Los Angeles basin, which are principally sensitive to Qs in the low-velocity, near-surface sediments of the basin.|
独立行政法人建築研究所国際地震工学センターの研修生として 4月から強震動地震学分野に滞在しているBanu Sanliさん(トルコBogazigi大学大学院生)に 当分野での3ヶ月間の成果を報告していただきました。
|Title:||The Strong Motion Simulation of the June 2000 Iceland Earthquake of Mw = 6.5 by Using Empirical Green's Function Method|
The South Iceland Seismic Zone was struck by a damaging earthquake
sequence in June 2000. The sequence started on 17 June, with a magnitude
6.5 (Mw) earthquake in the eastern part of the zone. It was followed by
great seismic activity stretching over nearly 100 km long area
stretching towards west. The largest aftershock is with a Mw:6.4 on 21
June, with an epicenter approximately 17 km west of the mainshock.|
The aftershocks in their epicentral areas, extended for about 16-18 km N -S, and from the surface down to about 10 km depth. Seismicity increased over a large area in SW Iceland following the June 17 mainshock. The two biggest earthquakes were accompanied by around 20 km surface faulting.
The main purpose of this study is to estimate the source model of Mw:6.5 mainshock using Empirical Green's Function Methodology developed by Irikura (1986).