Ocean Subbottom Seismometer System Installed in Deep Sea Drilling Project Hole 581C, Leg 88: A Technical Review

摘要

A permanent Ocean Sub-bottom Seismometer (OSS IV) designed and built by the Hawaii Institute of Geophysics was successfully installed in DSDP Hole 581C during Leg 88. The system consists of a borehole package, electromechanical cable, recorder package, recovery rope, and buoy. The borehole package contains vertical and horizontal geophones, tilt meters, and a temperature sensor. Signals from these sensors are multiplexed, digitized, and telemetered through the electromechanical cable to the recorder package near the ocean bottom, approximately 4 km from the borehole. Data are recorded continuously for up to two months on magnetic tape cassettes. The digital data are also monitored during installation and during servicing of the recorder package, which may be performed with a midsized oceanographic ship (>50 m) at any time after the installation. Data in digital format from the OSS IV installation were recorded during installation in September, 1982, and the recorder package was first serviced in May 1983. Data continuously recorded for 65 days were recovered from the first recorder package. A second recorder package was installed in May 1983 and is presently awaiting funding for servicing. Keywords: Deep Sea Drilling Project; Seismic data.