Publication Date:
2017-04-03
Description:
The U.S. Geological Survey deployed a digital seismic station in Oceano, California, in February 2004, to investigate the cause of damage and liquefaction
from the 22 December 2003 Mw 6.5 San Simeon earthquake. This station
recorded 11 Mw 2.8 aftershocks in almost 8 weeks. We analyze these recordings,
together with recordings of the mainshock and the same aftershocks obtained from
nearby stations in Park Hill and San Luis Obispo, to estimate the mainshock ground
motion in Oceano. We estimate the Fourier amplitude spectrum using generalized
spectral ratio analysis. We test a set of aftershocks as Green’s functions by comparing simulated and recorded acceleration amplitude spectra for the mainshock at San Luis Obispo and Park Hill. We convolve the aftershock accelerograms with a stochastic operator to simulate the duration and phase of the mainshock accelerograms. This approximation allows us to extend the range of aftershocks that can be used as Green’s functions to events nearly three magnitude units smaller than the mainshock.
Our realizations for the mainshock accelerogram at Oceano yield peak ground accelerations distributed as 28% +/- 4%g. We interpret these realizations as upper
bounds for the actual ground motion, because our analysis assumes a linear response, whereas the presence of liquefaction indicates that the ground behaved nonlinearly in Oceano.
Description:
U.S.G.S
University of Naples “Federico II”
University of Rome “La Sapienza,”
Description:
Published
Description:
1437–1447
Description:
4.1. Metodologie sismologiche per l'ingegneria sismica
Description:
JCR Journal
Description:
reserved
Keywords:
Stochastic,
;
simulation,
;
ground motion,
;
spectral ratio
;
Green’s function
;
earthquake
;
04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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