← Back to Sessions

WITHDRAWN Evaluating Subsurface Imaging Performance with Ocean-bottom Distributed Acoustic Sensing and Double Beamforming

Description: 

WITHDRAWN The high cost of active surveys and the scarcity of underwater instruments hinder the availability of seismic imaging in oceanic environments. Ocean-bottom Distributed Acoustic Sensing (OBDAS) can help to illuminate the subsurface with unprecedented sampling density. In this study, we utilize OBDAS data along a 60-km cable perpendicular to the coast of Oregon to image the continental shelf subsurface. We extract coherent surface waves from ambient seismic fields with cross-correlation and stacking. To measure dispersions of both the fundamental modes and higher overtones, we apply a double-beamforming (DBF) workflow across different array subsections with a spatial averaging technique. We perform a perturbational-based inversion scheme to reliably invert for S-wave velocities over the first 2000 meters of the subsurface underlying the fiber-optic cable. By comparing our results with the 1D slant-stack approach, we demonstrate the applicability of the DBF method on the OBDAS dataset and the enhanced spatial resolution of this approach. From our single-mode DBF results, we observe a coherent layering feature in the Florence shelf-sea region, while multi-mode DBF results reveal smaller-scale heterogeneity in the study region.

Session: Fiber-optic Sensing Applications in Seismology [Poster]

Type: Poster

Date: 4/15/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Yaolin

Student Presenter: Yes

Invited Presentation: 

Poster Number: 57

Authors