Cruise report of 2004 seismic reflection surveys in Izu-Ogasawara Arc

Abstract

In order to obtain detailed crustal structures in a typical oceanic island arc system, we have been conducting multichannel seismic (MCS) reflection survey in the Izu-Ogasawara region, by using R/V Kairei of Japan Agency for Marine-Earth Science and Technology (JAMSTEC). Swath-bathymetry, geomagnetic and gravity data are simultaneously observed during the cruises. In 2004 fiscal year, we collected a total of 2030.9 km of MCS data: 228.20 km in KR04-10, 384.70 km in KR04-13 and 1417.95 km in KR04-15 cruises. On-board processing results demonstrate clear seismic reflection images of the subducting Pacific plate, forearc tectonic features and backarc basin structures, showing that all of the MCS data collected are of good quality.