LONG-PERIOD PRESSURE FLUCTUATIONS RECORDED BY FIBER-OPTIC SENSING TECHNOLOGY

Abstract

 Distributed Acoustic Sensing (DAS), one of the fiber-optic sensing technologies, can observe strain along a fiber-optic cable densely in time and space. We conducted the DAS measurement using the submarine cable off Cape Muroto, Japan, with fiber length of 120 km. In this study, we elaborate long-period pressure fluctuations by examining the acquired dataset of both the DAS and the pressure gauge nearby during typhoons approach. The infragravity waves with a period of about 100 s were observed in addition to the ocean microseisms in the DAS measurement. Our in-situ observations suggest that DAS is sensitive to long-period pressure fluctuations and can detect pressure fluctuations induced by storm surge or tsunami.