Real Time Deep Sea Floor Observatory off Hatsushima Island in Sagami Bay

This station is equipped with revolving and fixed underwater color cameras, underwater lights, a 3-velocity seismometer, a wide-area hydrophon, 2 ground thermometers, magnetic flow meters, a CTD recorder (inductance, water temperature, depth gauge) and a transponder. The ground observation station on Hatsushima Islands is connected to an underwater station by an 8 km compound, a fiber-optic cable that sends observation data to the island station is sent on a real-time basics. This data is in turn supplied to the JAMSTEC in Yokosuka using normal telephone lines. The underwater station has made it possible to comprehensively monitor the chemoautotrophic clams, ground temperature, water temperature, salinity, current direction and speed and earthquakes that occur in this area. this is the first attempt of its kind to achieve such comprehensive monitoring of a single location.

Results have shown the number of clams vary significantly according to the time year and they need to live in areas where the ground is warmer and where the upwelling currents are flowing mainly to the west. We expect to obtain more valuable information from our underwater station.

The underwater unit

Hatsushima land station

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