2009 年 61 巻 Supplement 号 p. 1-7
After the 1995 Hyogoken-Nanbu earthquake, National Research Institute for Earth Science and Disaster Prevention (NIED) has constructed new nation-wide high sensitivity seismograph network. We call this network “NIED Hi-net” or “Hi-net”. Hi-net stations uniformly cover the Japanese Islands in addition to old high sensitivity seismographs. To reduce the seismic noise near the ground surface, a three-component velocity-type seismograph is installed at the bottom of a borehole. Recorded signal at each station is continuously transmitted to NIED data management center (DMC) at Tsukuba using IP-VPN technology. Hi-net waveform data are sent to the JMA and other related institutes for seismic activity monitoring and seismological research. NIED archives all waveform data generated by the Hi-net and other seismic networks. These waveform data and JMA hypocenter catalog are open to the public via the Hi-net website. Although less than 10 years has passed since the Hi-net data became available, this network has brought us a lot of contributions to geoscience. Stable and long-term observation by this seismograph network may play important roles to mitigate earthquake disasters and to predict earthquakes.