海底精密音響測距-水平方向の海底地殻変動観測

抄録

The advent of geodetic measuxements by GPS has made it a realistic research objective to observe the process of intra-plate deformations near plate boundaries, where seismicity and volcanism are most active on the earth. Most of plate boundaries, however, are located beneath the deep ocean. Marine geodetic measurements, therefore, are of prime importance to the study of geodynamics.
Precise acoustic ranging with cm-resolution per kilometers, which is the primary technique for marine geodetic measurements, has been examined in trial seafloor experiments. Based on the precise acoustic ranging, marine geodetic measurements are pursured in two ways. One is horizontal seafloor ranging between a fault zone. This experiment is simpler and easier owing to stable temperature and salinity in the deep ocean. The other is precise seafloor positioning combined with GPS geodetic measurements on the sea surface. Although this experiment is difficult, it can observe intra-plate deformations near the subduction zones.