Absolute gravity measurement

The IAGBN aims to distribute gravity points worldwide and construct a network on which gravity observation is based. There are two kinds of points: A is a point set up in regions with stable crustal structure, and B is a point set up in regions where crustal activity is expected. Syowa Station in Antarctica was among the 36 A points. McMurdo Station of the U.S. is the only point in Antarctica other than Syowa Station that is classified as A. Introduced GSI in 1980, the upcast-type absolute gravity meter (GA60) generally called the Sakuma type, was used in this survey. The 36th JARE (1994) conducted observation using FG5 that the GSI introduced in 1992. Because FG5 measures gravity in a free-fall system, it is characterized by the ability to conduct automatic continuous measurement and allow for many measurements.