Occurrence of soupy disturbance in long piston coresfrom marginal seas of the Japanese Islands

Abstract

Soupy disturbances appeared in the long piston cores taken from the Oki Ridge, off Shiretoko, off Kashima and off Kochi during IMAGES Vil-WEPAMA Leg 2 (May-June 2001). The soupy disturbance layers were cold when the core was recovered, and they expelled the mixture of gas, water and mud through drilled holes of the core liner tube. This suggests the dissociation of gas hydrates in the core onboard. Because the presence of soupy disturbance does not prove the existence of gas hydrate by itself, we need to obtain additional evidences in a future long piston coring study.