Seismic structure of the source region of the 2007 Chuetsu-oki earthquake revealed by offshore-onshore seismic survey: Asperity zone of intraplate earthquake delimited by crustal inhomogeneity

2012 ◽  
Vol 562-563 ◽  
pp. 34-47 ◽  
Author(s):  
Kazuo Nakahigashi ◽  
Masanao Shinohara ◽  
Eiji Kurashimo ◽  
Tomoaki Yamada ◽  
Aitaro Kato ◽  
...  
Keyword(s):  
Source Region ◽  
Seismic Survey ◽  
Seismic Structure ◽  
Intraplate Earthquake ◽  
Crustal Inhomogeneity

Extracting subsurface information from ambient seismic noise — A case study from Germany

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. KS13-KS31 ◽  
Author(s):  
Alexander Goertz ◽  
Barbara Schechinger ◽  
Benjamin Witten ◽  
Matthias Koerbe ◽  
Paul Krajewski
Keyword(s):  
Seismic Noise ◽  
Body Wave ◽  
Source Region ◽  
Low Frequency ◽  
Spectral Ratio ◽  
Velocity Model ◽  
Body Waves ◽  
Seismic Survey ◽  
Ambient Seismic Noise ◽  
Oil Reservoir

We analyzed ambient seismic noise from a broadband passive seismic survey acquired in an urban area in Germany. Despite a high level of anthropogenic noise, we observe lateral variations in the quasi-stationary spectra that are of natural origin and indicative of the subsurface in the survey area. The best diagnostic is the ellipticity spectrum which is the spectral ratio of the vertical over the horizontal components. Deviations of the observed spectra from a pure Rayleigh-wave ellipticity allow an approximate separation of surface-wave from body-wave components in the analyzed frequency range, distinguishing shallow (upper tens of meters) from deeper (upper three kilometers) subsurface effects. We observe an increase of vertically polarized body waves between 1 and 4 Hz that is correlated to a subsurface structure that contains an oil reservoir at about 2-km depth. We located the source of the observed body wave microtremor in depth by applying an elastic wavefield back projection and imaging technique. The method includes normalization by the impulse response of the velocity model, effects of the receiver geometry, and lateral variation of incoherent noise. The source region of the low-frequency body wave microtremor is centered above the location of the oil reservoir. Two possible explanations for the deep microtremor are elastic body-wave scattering due to the impedance contrast of the structural trap, and viscoelastic scattering due to poroelastic effects in the partially saturated reservoir.

scholarly journals Seismic structure and tectonics of the continental wedge overlying the source region of the Iquique Mw8.1 2014 earthquake

2020 ◽  
Vol 796 ◽  
pp. 228629
Author(s):  
Gabino Reginato ◽  
Emilio Vera ◽  
Eduardo Contreras-Reyes ◽  
Anne M. Tréhu ◽  
Andrei Maksymowicz ◽  
...  
Keyword(s):  
Source Region ◽  
Seismic Structure

Dukhan 3D: An Ultra High Density, Full Wide Azimuth Seismic Survey for the Future

2009 ◽  
Author(s):  
Salva R. Seeni ◽  
Scott Robinson ◽  
Michel Denis ◽  
Patrick Sauzedde
Keyword(s):  
High Density ◽  
Seismic Survey ◽  
The Future
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