JMA'snewOceanBottomSeismographs (OBS)using marine cable installed attheSeaofEnshutotheSeaofKumano

JMA started aproject in2004toinstall new Earthquakes. However, wedonothaveenough knowledge OceanBottomSeismographs (OBS)using marine cable at ofthedetail ofseismic activity intheassumed focal region aroundassumedfocal regions ofanticipated Tokaiand ofTonankai Earthquake. Theassumedfocalregion of TonankaiEarthquakes. JMA installed OceanBottom Tonankai Earthquake isthewestofthatofTokai Seismographs (OBS)in1978atassumed focal region ofTokai Earthquakes. earthquake attheSeaofEnshu, andhasbeenkeeping seismic Toimprove thecapability ofhypocenter determination in observation using them;thestarted project istoinstall new therevised assumed focal region oftheTokaiandTonankai OBSonwestoftheexisting OBS. Earthquakes andmaketheestimation ofhypocenter and TheaimofnewOBSisimprovement ofdetection ability of magnitude moreaccurate forthecalculation ofearly smallearthquakes, andalsopromptdetection oflargeearthquake warning, JMA started in2004a project to earthquake andprecise determination ofitsmagnitude for install newOBSusing marine optical cables andarepeater early earthquake warning. inandaround theassumed focal regions oftheTokaiand