KiK-net

KiK-net
Name	KiK-net
Caption	Strong-motion seismic network in Japan
Established	1997
Operator	National Research Institute for Earth Science and Disaster Resilience
Country	Japan
Stations	~700

KiK-net KiK-net is a Japanese strong-motion seismic observation network built to record broadband ground motions from earthquakes and reduce seismic hazard through data-driven research. The network supports earthquake engineering, seismology, and disaster mitigation by providing high-quality accelerograms and velocity seismograms for events ranging from microseisms to megathrust earthquakes. It interfaces with national and international institutions for rapid data sharing, contributing to operational systems for early warning, building codes, and tsunami assessment.

Overview

The network comprises a dense array of borehole and surface stations distributed across Honshu, Hokkaido, Shikoku, and Kyushu, operated by the National Research Institute for Earth Science and Disaster Resilience and affiliated laboratories such as the University of Tokyo and Tohoku University. Designed after major events including the 1995 Great Hanshin earthquake and the 1993 Hokkaido Nansei-Oki earthquake, it complements other Japanese systems like JMA seismic network and integrates with global initiatives involving the United States Geological Survey, International Seismological Centre, and the Global Seismographic Network. KiK-net stations provide data used by agencies such as the Cabinet Office (Japan) and research programs at the Earthquake Research Institute, University of Tokyo.

History and development

Development began in the late 1990s following policy responses to the Great Hanshin earthquake and recommendations from committees formed after the 1995 Kobe disaster. Initial deployment was influenced by international collaborations with the USGS and researchers from the California Institute of Technology and Massachusetts Institute of Technology. Funding and coordination involved the Ministry of Education, Culture, Sports, Science and Technology (Japan), the Japan Society for the Promotion of Science, and local prefectural governments such as Hyogo Prefecture and Miyagi Prefecture. The network expanded through programs tied to events like the 2004 Chūetsu earthquake and the 2011 Tōhoku earthquake and tsunami, with upgrades following findings by commissions such as the Central Disaster Management Council.

Network and instrumentation

Stations typically include paired surface accelerometers and borehole instruments installed to depths of several tens to hundreds of meters, calibrated against standards set by organizations like the International Association of Seismology and Physics of the Earth's Interior. Instrument models from manufacturers used in deployments have provenance linked to laboratories at Kyoto University, Nagoya University, and the National Institute for Materials Science. Site selection involved geotechnical surveys referencing data from the Geological Survey of Japan and mapping by the Geospatial Information Authority of Japan. The array architecture interoperates with telemetry systems used by the Japan Meteorological Agency and exchanges timing via networks synchronized to Japan Standard Time and international time signals from entities such as NICT.

Data processing and distribution

Raw accelerograms undergo quality control, baseline correction, and instrument response removal using pipelines developed in collaboration with research groups at the Kobe University and the Disaster Prevention Research Institute, Kyoto University. Processed products include peak ground acceleration, velocity time series, and spectral ordinates that feed into structural models at institutions like the Building Research Institute and computational platforms at the RIKEN supercomputing centers. Data dissemination follows protocols compatible with the SeisComP framework and data formats standardized by the International Federation of Digital Seismograph Networks, enabling access for the Earthquake Early Warning system and archives held by the National Research Institute for Earth Science and Disaster Resilience.

Scientific applications and findings

KiK-net data have underpinned discoveries about site amplification effects in basins studied at locations including Kanto Plain, Osaka Plain, and Sendai Plain, influencing seismic hazard maps produced by the Japan Seismic Hazard Information Station. Analyses contributed to rupture characterization of events like the 2011 Tōhoku earthquake and tsunami and source studies comparable to work on the 1994 Northridge earthquake and the 1999 İzmit earthquake in international literature. Results have advanced ground-motion prediction equations used by the Building Standard Law of Japan revisions and informed retrofit projects at facilities managed by the Ministry of Land, Infrastructure, Transport and Tourism. Cross-disciplinary research with teams from ETH Zurich, Imperial College London, and Pace University has leveraged KiK-net records for nonlinear site response, soil-structure interaction, and tsunami-triggered landslide studies.

Operations and maintenance

Routine operations are coordinated by the National Research Institute for Earth Science and Disaster Resilience with regional support from universities and municipal partners such as Sendai City and Fukuoka City. Maintenance schedules incorporate calibration campaigns, borehole upkeep, and telemetry redundancy planning developed with companies like NTT and contractors certified by the Ministry of Internal Affairs and Communications. Emergency procedures tie into national response frameworks including the Disaster Countermeasures Basic Act and local disaster management plans, with post-event inspections coordinated with agencies such as the Fire and Disaster Management Agency (Japan). Continuous training and capacity building involve seminars at the Earthquake Research Institute, University of Tokyo and exchange programs with the USGS and European Seismological Commission.

Category:Seismology Category:Earthquake engineering