Geophysical investigation of methane seeps on the NE Sakhalin continental slope, Sea of Okhotsk

Abstract

During CHAOS (2003, 2006) and SSGH projects (2007), acoustic investigation including hydroacoustic (HA), side-scan sonar (SSS) and highresolution sparker seismic (HSS) surveys was carried out on the northeastern Sakhalin slope (53°56' N, 143°52' E to 54°40' N, 144°32' E). More than 130 methane seeps with high backscatter intensity are identified on SSS mosaic, which are well accompanied with gas flares in the water column on HA profiles and subbottom gas chimneys on HSS profiles. It is likely that that some seeps align along a NW strike parallel to the Lavrentiev Fault.