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| Titel |
Improving the seismic imaging in the southern Ryukyu subduction system by using multiple attenuation methods |
| VerfasserIn |
Ci-Jhu Lyu, Hao Kuo-Chen, Kirk McIntosh, Francis Wu, Char-Shine Liu |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105685
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| Publikation (Nr.) |
 EGU/EGU2015-5221.pdf |
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| Zusammenfassung |
| The southern Ryukyu subduction system is at the boundary where the Philippine sea plate
subducts northwestward beneath the Eurasian plate near the Taiwan orogen. In previous
studies, the boundary where the PSP subducts northward beneath the EP have no clear
answers due to a lack of high-resolution crustal-scale geophysical constraints. We want to
know the Moho boundary. We analyze in this study the dynamics of SRA system with
TAIGER program of 2009, multi-channel marine seismic reflection (MGL0906_23,
MGL0906_28, MGL0906_26A, MGL0906_13, MGL0906_18N). Data area covers about
30,000 km2. Shots are spaced every 50 m, hydrophones are spaced every 12.5 m, and CDP
spacing is 6.25 m. Recording length is 15 s. Signal of the source is low frequencies
(20Hz~60Hz), which can penetrate the shallow sediments and reflex signal of the deep crust.
Because multiple can affect the deep structure signals. Therefore, we use a variety of
methods to remove multiple effects, and increase Moho signals. In this study, we use
four ways to remove the multiple. (1) Increases CDP spacing. (2)Deconvolution.
(3) Surface Related Multiple Elimination (SRME). (4)Radon Transform multiple
attenuation. From the TAIGER marine reflection data. The shallow structure are Huatung
Basin, Yeyama Accretionary Prism, Forearc Basin and Ryukyu Arc (from south to
north), respectively. We discover a lot of transform fault zone, and account these
stress related with shear zone of Ryukyu subduction system. The deep structure, the
crust of PSP velocity is about 5~7 km/s, the PSP Moho velocity is 7.5 km/s. In
multichannel reflection seismic, the PSP Moho deep is about 15~20 km under the
seabed.
Keywords: multiple; Moho boundary; subduction zone; southern Ryukyu Arc (SRA) |
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