Subsurface Imaging With Ocean‐Bottom Distributed Acoustic Sensing and Water Phases Reverberations
Abstract
Seismic waves from earthquakes recorded on the seafloor are composed of complex multiple arrivals. Here, distributed acoustic sensing (DAS) observations along a cable located offshore the Sanriku Coast, Japan, show that the local earthquake wavefield is particularly rich in Scholte waves. We introduce a processing pipeline to extract these surface waves from DAS records. We then invert hundreds of dispersion curves along a section of the cable to form a shallow high‐resolution shear‐wave velocity model. Moreover, we focus on the possible generation mechanisms of Scholte waves through a series of 2D and 3D full‐wavefield numerical simulations. We show that water phase reverberations greatly contribute to the generation of Scholte waves on the ocean floor. This study demonstrates the potential of DAS to observe and better understand a poorly known marine wave phenomenon and image the offshore shallow seismic structure with an unprecedented spatial resolution.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 19, 2022
- Source ID
- 10.1029/2021gl095287
Entities
People
- Jorge C. Castellanos
- Kiwamu Nishida
- Loïc Viens
- Masanao Shinohara
- Takeshi Akuhara
- Tomoaki Yamada
- Zack Spica
Organizations
- Air Force Research Laboratory
- California Institute of Technology
- Gordon and Betty Moore Foundation
- University of Michigan
- University of Tokyo