Utilizing distributed acoustic sensing and ocean bottom fiber optic cables for submarine structural characterization
| Autor: | Benxin Chi, T. Craig Dawe, Jonathan B. Ajo-Franklin, Feng Cheng, Nathaniel J. Lindsey |
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| Rok vydání: | 2020 |
| Předmět: |
010504 meteorology & atmospheric sciences
Science Ambient noise level Active fault 010502 geochemistry & geophysics 01 natural sciences Article law.invention law Life Below Water Seismology 0105 earth and related environmental sciences Optical fiber cable Multidisciplinary Physical oceanography Submarine Distributed acoustic sensing Interferometry Geophysics Medicine Submarine pipeline Geology Subsea |
| Zdroj: | Scientific Reports Scientific Reports, Vol 11, Iss 1, Pp 1-14 (2021) Scientific reports, vol 11, iss 1 |
| ISSN: | 2045-2322 |
| Popis: | The sparsity of permanent seismic instrumentation in marine environments often limits the availability of subsea information on geohazards, including active fault systems, in both time and space. One sensing resource that provides observational access to the seafloor environment are existing networks of ocean bottom fiber optic cables; these cables, coupled to modern distributed acoustic sensing (DAS) systems, can provide dense arrays of broadband seismic observations capable of recording both seismic events and the ambient noise wavefield. Here, we report a marine DAS application which demonstrates the strength and limitation of this new technique on submarine structural characterization. Based on ambient noise DAS records on a 20 km section of a fiber optic cable offshore of Moss Landing, CA, in Monterey Bay, we extract Scholte waves from DAS ambient noise records using interferometry techniques and invert the resulting multimodal dispersion curves to recover a high resolution 2D shear-wave velocity image of the near seafloor sediments. We show for the first time that the migration of coherently scattered Scholte waves observed on DAS records can provide an approach for resolving sharp lateral contrasts in subsurface properties, particularly shallow faults and depositional features near the seafloor. Our results provide improved constraints on shallow submarine features in Monterey Bay, including fault zones and paleo-channel deposits, thus highlighting one of many possible geophysical uses of the marine cable network. |
| Databáze: | OpenAIRE |
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