Proposal for Robust Monitoring of Catastrophic Tsunami Using Onshore Strain and Tilt Geodetic Sensors

Abstract

Tsunami monitoring is fundamental and essential for disaster warnings and rescue operations. The gigantic tsunami caused by the Tohoku earthquake off Japan’s Pacific coast in 2011 completely destroyed tsunami observation facilities along the seashore. The subsequent lack of real-time monitoring data caused confusions in devastated area rescue operations. These experiences indicate a need for more robust tsunami monitoring techniques to enable catastrophic events observation. We tested a hypothesis on whether secure onshore strain and tilt sensors could be used as tsunami gauges. We compared data from tsunami gauges and strain and tilt meters for 2011 Japan and 2010 Chile tsunami events clearly indicating that geodetic sensors recorded tsunami signals well. The high correlation between geodetic signals and tsunami height indicated that tsunami height could be estimated using only onshore geodetic data, i.e., secure onshore strain and tilt meters could act as robust tsunami monitoring systems when catastrophic events occur.