Hi-net is aimed at microearthquake observations and supports the implementation of earthquake early warning

Hi-net　｜　High Sensitivity Seismograph Network Japan

 Hi-net is a high-sensitivity seismograph network consisting of nearly 800 stations with an average spacing of 20 km. The seismometers are installed at the bottom of boreholes at a depth of 100-3500 m to reduce noise caused by winds, ocean waves, and human activity. The observed data is continuously transmitted to NIED to be used for researching microearthquakes and other seismological phenomena.

Hi-net

Strong motion data from K-NET and KiK-net is utilized for real-time information on large earthquakes and assessments of earthquake hazards

K-NET　｜　Kyoshin Network

 K-NET is a strong motion seismograph network consisting of more than 1,000 stations with an average spacing of 20 km. The seismometers are installed on the ground surface and stay on scale even during strong shaking. Most of the K-NET seismometers are officially approved as seismic intensity meters. Seismic intensity from K-NET supports government decision-making.

K-NET/KiK-net

KiK-net　｜　Kiban Kyoshin Network

 KiK-net is a strong motion seismograph network consisting of pairs of seismometers installed on the ground surface and in the borehole together with the Hi-net high-sensitivity sensors. Surface and downhole observations provide important data to understand amplification of strong shaking near the surface.

K-NET/KiK-net

F-net broadband data facilitates rapid earthquake characterization and allows a better understanding of earthquake source processes

F-net　｜　Full Range Seismograph Network of Japan

 F-net is a broadband seismograph network consisting of about 70 stations nationwide. The seismometers are installed at the end of tunnels, several dozen meters from the entrance, where temperature and pressure are stable, and accurately measure ground motion over a wide frequency range. These broadband measurements provide useful implications for earthquake source mechanisms and the structure of the Earth.

F-net

V-net provides comprehensive monitoring of volcanic activity that helps estimate changes in the volume of volcano magma chamber

V-net　｜　The Fundamental Volcano Observation Network

 V-net is an observation network operated at 16 volcanoes in an effort to develop eruption forecast and volcano hazard mitigation. Several types of instruments are installed, including borehole seismometers, borehole tiltmeters, GPS receivers, and broadband seismometers. The borehole measurements at Mt. Miyake observed precursors to the eruption in 2000. At Mt. Asama, a radar interferometer is also installed, to monitor surface deformation from magma movement before and during eruptions.

V-net

Real-time measurements from ocean bottom observation networks, S-net and DONET, increase lead time of warnings for offshore earthquakes and provides prompt and accurate tsunami information

S-net　｜　Seafloor observation network for earthquakes and tsunamis along the Japan Trench

 S-net is an ocean bottom observation network consisting of 150 observation units from off Hokkaido to off Chiba Prefecture. Each unit contains seismometers and water pressure gauges to observe offshore earthquakes and tsunamis. All the data is transmitted to the land stations by fiber-optic cable and arrives at NIED in real time.

S-net/DONET

DONET　｜　Dense Oceanfloor Network system for Earthquakes and Tsunamis

 DONET is an ocean bottom observation network consisting of 51 stations in Kumano-nada and off Kii Channel, focused on monitoring of earthquakes and tsunamis in the region. A wide variety of instruments are installed, including strong motion seismometers, broadband seismometers, water pressure gauges, hydrophones, differential pressure gauges, and thermometers. The network is designed to be expandable and replaceable, allowing for adding stations and replacing instruments. The data is transmitted to research institutes and universities in real time, and improves precision and warning times of earthquake early warning and tsunami warnings/advisories by JMA.

S-net/DONET