|
| | Abstract | | The Izu-Bonin island arc is a typical oceanic island arc formed by subduction of the Pacific plate beneath the Philippine Sea plate. To clarify this detailed crustal structure, we conducted the wide-angle seismic survey using 85 ocean bottom seismographs (OBSs) deployed 1 km interval along the survey line from the volcanic front to the forearc region off the east of Aoga-shima in 2008. In the multi-channel seismic reflection (MCS) survey, this part is too deep to image the structure. In this study, using the dataset of OBSs including wide-angle reflection phases reflected from interfaces in the deep part, we obtained the detail velocity structure and applied the pre-stack depth migration (PSDM). Finally, we imaged the seismic reflection profile from the detailed crustal structure. In the result, we could find the strong reflector in the part of the survey line at about 4.5, 5.5, and 14 km depth. |
|
|
|
| |
|