Abstract
After the 1995 Hyogo-ken-Nanbu earthquake, new national projects have stated to improve seismic observation systems in Japan. A large number of strong-motion seismographs were installed to construct dense and uniform networks covering the whole of Japan. The K-NET is one of the nationwide strong-motion observation networks and consists of about 1, 000 strong-motion seismographs installed all over Japan. The strong-motion records obtained by the K-NET are available on the Internet. The operation of the K-NET began in June 1996. Ten years have passed since the K-NET started and many strong-motion records are obtained. During these years the progress in information technologies is remarkable and new technologies become to be available. The NIED has developed the new seismographs for the K-NET using the new technologies. The main features of the new strong-motion seismograph are functions for real time data communications and processing JMA seismic intensity. The new seismographs have been installed at 910 observatories. The operation of the new K-NET system started in June 2004.
