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Our networks Summary  Hi-net  K-NET  KiK-net  F-net  V-net  S-net  DONET  Column 

Nationwide observation network for earthquakes, tsunamis, and volcanoes over land and sea

 Following the Kobe earthquake on January 17, 1995, National Research Institute for Earth Science and Disaster Resilience (NIED) established four nationwide land observation networks, Hi-net, K-NET, KiK-net, and F-net, to improve understanding and assessments of earthquakes and their impacts. NIED also established V-net at 16 volcanoes to monitor volcanic activity.

 After the Tohoku earthquake on March 11, 2011, a seafloor observation network, S-net, was installed from off Hokkaido to off Chiba Prefecture for rapid detection of offshore earthquakes and tsunamis. In April 2016, NIED took over the operation of DONET, another seafloor network in Kumano-nada and off Kii Channel, from Japan Agency for Marine-Earth Science and Technology (JAMSTEC).


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.


  • distribution of earthquakes

    3D distribution of earthquakes from 2012 to 2016 captured by Hi-net

  • Sensor unit

    Sensor unit of Hi-net/KiK-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.


  • Seismometer

    Seismometer of K-NET

  • Station

    Station of K-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.


  • monitor

    Strong motion monitor

  • Station

    Station of Hi-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.


  • Station

    F-net station

  • Entrance

    Entrance of an F-net station

  • Seismometers

    Three-component broadband seismometers with a strong motion velocity seismometer

  • 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.


  • at Mt. Iwate

    V-net station at Mt. Iwate

  • at Mt. Asama

    Radar interferometer at Mt. Asama

  • 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.


  • Observation units

    Observation units of S-net

  • Water pressure gauges

    Water pressure gauges in the S-net observation units

  • Laying operation

    Laying operation of S-net

  • 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.


  • node

    Science node

  • Pressure sensing

    Pressure sensing system

  • Ground-motion sensing

    Ground-motion sensing system

  • Land station

    Land station of DONET

  • Column

    MeSO-net | Metropolitan Seismic Observation network


    Earthquake Research Institute (ERI) at the University of Tokyo established MeSO-net consisting of about 300 stations with a spacing of 2-5 km, to measure ground shaking and monitor seismic activity in the Tokyo metropolitan area. NIED took over the operation of MeSO-net from ERI in April 2017.


    Museum Exhibition

    Real-time seismic data from MOWLAS is displayed at several museums, which includes maps showing seismic activity and earthquake seismograms.

     National Museum of
       Nature and Science

     National Museum of Emerging
       Science and Innovation

     Nagoya City Science Museum

     Muroto Global Geopark Center