[SCG60-P02] The variation of seismic attributes about incoming oceanic crust in Nankai Trough using multi-channel seismic reflection data
MCS profiles of lines KY12-4 and SB01 were obtained along the Nankai Trough. These data were valuable for case study by comparison about physical properties from seismic attribute of top of oceanic crust. In order to extract the physical properties from the reflector of top of oceanic crust, we apply seismic attributes analysis for these data. Seismic attributes are measured from seismic data that can be analyzed in order to enhance information that might be well understanding in a traditional seismic image (Tarner et al. 1979). The seismic envelope attributes often use the reflection strength of the reflector (e.g. Tsuji et al. 2007). The envelope of seismic attributes means the envelope of seismic signal. These attributes are good for looking at packages of amplitudes. We select the second derivative of single envelope as reflection strength of top of oceanic crust. Although calculated seismic attributes of reflection strength indicate the high intensities in the central part of Shikoku Basin, the west and east part of Shikoku Basin where is initial stage of spreading of Shikoku Basin have the small intensities. This suggests that the reflection strength of top of oceanic crust is affected by the created condition of oceanic crust. We also discuss about the relationship between the reflection strength of top of oceanic crust and the thickness of sediments of Shikoku Basin.
This study is part of 'Research project for compound disaster mitigation on the great earthquakes and tsunamis around the Nankai trough region' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan.