An expandable deep seafloor monitoring system for earthquake and tsunami observation network

The Japan Marine Science and Technology Center is developing and installing the submarine cable systems for building a series of in-line geo-scientific observation network at typical seismogenic zones around Japan since 1995. The second observation system was deployed in July 1999 on the southern Kuril subducting zone in southeastern part of Hokkaido (Off Kushiro-Tokachi area). The system consists of three in-line ocean bottom seismometers, two in-line tsunami pressure gauges, a cable end multi sensor station, and two expandable interfaces. The mobile/replaceable sensor package named Adaptable Observation System was developed to connect to the expandable interface to extend the observation network from line to wider area.