Ocean Bottom Seismometer data of Makran subduction zone

This archive includes wide-angle seismic data collected in the Makran margin , Northern Indian Ocean, and the final P-wave velocity model.The ocean bottom seismometer (OBS) data was collected In February 2018 by the R/V “Shiyan 3” of the South China Sea Institute of Oceanology conducted the first joint China-Pakistan Northern Indian Ocean scientific cruise. Twenty-one four-component OBSs were deployed at a spacing of ~11 km, crossing the Dalrymple trough, Little Murray Ridge and the deformation front of Makran subduction zone from the Murray Ridge to Makran accretionary wedge, which is the first active OBS seismic profile spanning the Arabian Plate, Eurasian Plate and north side of Indian Plate.

Twenty OBS instruments were recovered, and two of them could not provide useful data. The seismic source was provided by an array of four BOLT air-guns with a total volume of 6,000 cubic inch. The shot interval was set to 90 s to meet the working pressure of ~2000 psi (13.8 MPa) leading to ~250 m shot spacing on average, and a total of 1096 useful shots were fired from northwest to southeast.