Long-period seismic amplification in the Kanto Basin from the ambient seismic field

Abstract

Tokyo, like many seismically threatened cities, is situated atop a sedimentary basin that has the potential to trap and amplify seismic waves from earthquakes. We study amplification in the Kanto Basin by exploiting the information carried by the ambient seismic field. We use 375 seismic stations from the high sensitivity seismograph network across central Honshu as virtual sources and 296 seismic stations of the Metropolitan Seismic Observation network shallow borehole seismometers within the basin as receivers to map the basin response. We find a linear relationship between ground motion and basin depth at periods of 2–10 s that could be used to represent 3‐D basin effects in ground motion prediction equations. We also find that the strength of basin seismic amplification depends strongly on the direction of illumination by seismic waves.

Development and Testing of a 3D Seismic Velocity Model of the Po Plain Sedimentary Basin, Italy

“…Relations have been proposed between ground motion and basin depth in specific seismic period bands (e.g., Hruby and Beresnev, 2003;Denolle et al, 2014). Sedimentary basins have shown to amplify specific frequencies.…”

Northern Aegean Earthquake (Mw=6.9): Observations at three seismic downhole arrays in Istanbul

“…Based on the measured velocities, researchers reported that the basin can enhance the ground motion amplitude and duration at periods between 2 and 5-7 s [40]. Denolle et al [10] proposed a linear relationship between ground motion and basin depth at periods of 2-10 s that could be used to represent 3-D basin effects in ground motion prediction equations. They also find that the strength of basin seismic amplification depends strongly on the direction of the seismic wave propagation.…”

Observations and Modeling of Long‐Period Ground‐Motion Amplification Across Northeast China

“…Hence, the standard one-dimensional (1-D) ground response analysis, which considers the effect of near-surface geology on vertically propagating shear waves or simply uses empirical proxies (e.g., Vs30), often underestimates the observed amplifications (e.g., Steidl, 2000). Such basin resonance effects can also be captured by observations of the ambient seismic field (e.g., Bowden 2014; Denolle, Miyake, et al, 2014;Viens et al, 2016). As such, much effort has been devoted to 3-D numerical simulations of earthquake ground motions in sedimentary basins (e.g., Böse et al, 2014;Chaljub et al, 2015;Frankel et al, 2009;Iwaki & Iwaka, 2010;Olsen, 2000;Olsen et al, 2006;Pilz et al, 2011).…”