2-6. Ocean Hemisphere Network Data Center

The Ocean Hemisphere Project Data Management Center (OHPDMC) was established in 1997 to provide research communities with an easy-to-use data distribution service. The OHPDMC provides seismic, geomagnetic, and geodetic data from the OHP network and other related networks. In addition to these required tasks, we developed a new data distribution system by applying JAVA RMI, a recent IT technology for networked systems (Takeuchi et al., 2002). This system realizes a network data center and provides a unified interface such that a user can download data from various data centers on the Internet.
Following the establishment of IFREE within JAMSTEC, OHPDMC began to closely cooperate with IFREE in running the data center. The OHPDMC plays an important role, especially in real-time data transmission. We have been replacing the observation system since 2002, and seven of ten broadband seismic stations, four of nine geomagnetic stations, and all four submarine cables (measuring voltage differences) are now online. These data are beginning to be applied to a preliminary real-time data analysis (Fig. 2.6.1).