Ocean Hemisphere network Project
OHP


Group III < System development >

To further improve the observational network, this group is developing new instrumentation and technology as follows.

( 1 ) A high performance ocean bottom seismometer system
This system will enable us to make long term ( typically for several years ) broad-band seismic observations on the seafloor. This system is based on the most advanced OBS technology used in temporal array studies. The sensor will be installed in the ODP hole if possible. The technical problems to be solved are the requirements for memory, power supply, data transfer, and overcoming the long period noise expected on the seafloor.
( 2 ) Ocean bottom geomagnetic observatory
A performance comparable to standard geomagnetic observatories is required of this system. This system will be installed in the northwest Pacific.
( 3 ) A high performance magnetometer system for Pacific islands
This is a highly automated system designed especially for the observations on Pacific islands carried out by Group I. The system consists of scalar proton and vector fluxgate magnetometers, a recording unit, a power supply unit, and a GPS synchronized clock.
( 4 ) Observations by use of submarine cables
Submarine cables in the Pacific, retired from telecommunications service, are being utilized for measurement of electric field variations on a global scale to study the distribution of electrical conductivity in the mantle and the dynamics of the core. In the future, seafloor sensors may be connected to one of such submarine cables to obtain power and to transmit data.
( 5 ) Ocean bottom geodesy and geothermometry
Monitoring systems for seafloor geodetic and crustal heat flow measurements will be developed. In the geodetic study, vertical crustal movement will be monitored by simultaneous measurement of pressure and gravity on the seafloor.
( 6 ) Superconducting gravimetry
Two superconducting gravimeters will be installed in Australia and Indonesia. By combing the new data with data from pre-existing sites, more detailed information is expected to be obtained on the Earth's deformation, the Earth's rotation, the Earth's free oscillation, and core dynamics.
( 7 ) Acoustic communication from ocean bottom to surface
Development of this and other technologies including long-life batteries and satellite telecommunications from sea surface is essential to realize the potential of the above new observation systems.

( Y. Hamano )

For communication regarding this page, please contact: here

Ocean Hemisphere Research Center
Earthquake Research Institute
University of Tokyo
1-1-1 Yayoi, Bunkyo-ku, Tokyo
113-0032 Japan
tel: 81-3-3812-2111