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Titel |
Crustal structure and seismicity of the far-eastern Eurasian continental margin around the Korean Peninsula |
VerfasserIn |
Tae-Kyung Hong, Hoseon Choi, Xiaobo He, Kiwook Lee, Dong Geun Ji, Eunyoung Jo |
Konferenz |
EGU General Assembly 2011
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 13 (2011) |
Datensatznummer |
250050204
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Zusammenfassung |
The Korean Peninsula and its neighboring regions compose
the far-eastern continental margin of the Eurasia plate,
and have experienced complex tectonic evolutions
including continental collisions and a rifting. Such
complex tectonic evolutions accompanied significant
crustal deformation. The crustal and upper mantle
structures of this region have been poorly understood. We
investigate seismic velocities on the Moho, seismic
attenuation and shear-wave splitting in the crust of this
region. We also present focal-mechanism solutions of the
events in this region. We find strong correlation of
seismic velocities and attenuation with the tectonic
structures. The average Vp/Vs ratio is determined to be
1.69, which is lower than the value of Poisson solids.
Also, the Vp/Vs ratios appear to vary with tectonic
structures. The Conrad discontinuity is clearly
identified from analyses of regional seismic waveforms,
and is observed across the southern Korean Peninsula. The
fast polarization directions of crustal shear waves
appear to be highly correlated with the ambient stress
field that is inferred from the focal-mechanism analysis.
High-speed subductions of the Pacific and Philippine Sea
plates beneath the Japanese islands make contraction in
the region around the East Sea (Sea of Japan), causing
reverse activation of paleo-tectonic structures. We find
that regional-wave amplitudes are highly dependent on the
crustal structures. We determine the body-wave magnitudes
of events occurring around the Korean Peninsula. |
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