| Popis: |
The Vertical Cable Seismic (VCS) survey is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by seismic sources. Because the VCS is an efficient high-resolution 3D seismic survey method for a spatially bounded area, we proposed it for the SMS survey tool development program started by Japanese government. In 2010, we manufactured the autonomous VCS data acquisition systems. Through several experimental surveys, our VCS is successfully completed. In 2011 and 2013, we carried out the two VCS surveys using GI gun and high-voltage sparker respectively in the Izena Cauldron, Okinawa Trough, which is one of the most promising SMS areas around Japan. Because seismic survey is not proven to be effective for SMS exploration, no seismic surveys have been conducted there so far. However, our VCS results are consistent with geological information from the cores of the nearby borehole and give useful information to SMS exploration.. In 2014, the Japanese government started the Cross-ministerial Strategic Innovation Promotion Program (SIP), which includes "Next-generation technology for ocean resource exploration". Our Vertical Cable Seismic (VCS) survey technique is accepted by this program, especially for the exploration of Seafloor Massive Sulfides (SMS) and we continue its development. |
