The ocean covers 70% of the surface of our planet, but the underwater environment is limited by access and by exceptionally high costs and complex logistics. Yet, underwater measurements are crucial for offshore seismic hazard, tsunami and earthquake early warning, submarine volcano science, and crustal and deep earth imaging. Strategies explored so far to access the seafloor require expensive field campaigns, including several days to weeks of ship time, and long-term management either of cabled nodes, ships, or instrument pools. Upscaling any strategy to monitor the seafloor worldwide is difficult to envision. Fiber-optic sensing provides a novel promising avenue for making high-resolution seafloor measurements offshore and tackling the scientific questions that cannot be answered otherwise.
Following recent short-time successful experiments offshore, this research proposes to develop the first continuously operating Distributed Acoustic Sensing (DAS) experiment in a marine environment using the Monterey Accelerated Research System (MARS) cable in Monterey Bay, CA. The Seafloor seismology with a Fiber-Optic Array in Monterey Bay (SEAFOAM) project will demonstrate, calibrate, use, and expand the capabilities of fiber-optic sensing in marine geophysics, including growing the DAS user community through release of open access data. The project consists of a 1-year experiment with the MARS cable in order to record earthquakes, and extend our knowledge of the ambient seismic background wavefield recording interval over several tidal, storm, and seasonal cycles. This project will also deliver a software-hardware system that will provide an example pathway for continuous, real-time, open DAS data streaming to a seismological data archive.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.