A new approach for long-term seafloor monitoring and data recovery

As a new approach for low cost long-term seafloor monitoring, the Mobile Seafloor Observatory, which has a depth capability of 6000 m, was developed and tested at sea. The observatory comprises of a multi-sensor Mother Station and four Satellite Stations. The Mother Station is equipped with a velocity type seismometer, a Tsunami pressure gauge, a digital camera with flash, a CTD, an electromagnetic current meter, two heat flow temperature probes, a hydrophone and 16 pop-up buoys. Part of the data in Mother Station could be monitored monthly through satellites by releasing pop-up buoys. After one gear long observation, all the data in 8 GB hard disc is retrieved by recovering the station. Each Satellite Station comprises of a long-term velocity type digital ocean bottom seismometer (OBS) which could be recorded three-component seismic data continuously for more than 50 days. The data in 2 GB Exabyte tape could be retrieved by recovering the station. They are deployed around the Mother Station at separations between 20 and 50 km, The observatory was tested at a depth of 1377 m for four months, and will be deployed onto the Shikoku Basin at 4300 m deep to carry out comprehensive seafloor monitoring.