Implementation Plan for the Cascadia Offshore Subduction Zone Observatory
Description:
The Cascadia Offshore Subduction Zone Observatory (COSZO) is an NSF-funded mid-scale infrastructure project that will add new geophysical capabilities to NSF’s Ocean Observatories Initiative Regional Cabled Array (RCA). The Cascadia subduction zone is an endmember among global subduction systems which is characterized by warm young subducting lithosphere blanketed by thick sediment cover and a resulting seismogenic zone that is narrow and shallow. Geodetic observations and a dearth of offshore seismicity near the plate interface suggest that the megathrust is locked in many places from near the coastline to the deformation front. However, off central Oregon, the geophysical observations are consistent with a narrowly locked megathrust near the deformation front that transitions to creeping behavior beneath the shelf where there are two distinct clusters of earthquakes on the megathrust, including repeating and very low frequency earthquakes. Although the RCA was sited off Newport, Oregon to support coastal oceanography, it is well positioned to study the transition in megathrust locking off central Oregon. The COSZO project will add science junction boxes to three primary nodes on the continental slope and shelf that currently do not support seafloor geophysical observations. Each science junction box will host a sensor suite comprising a buried broadband seismometer, strong motion accelerometers, a low-frequency hydrophone, a pressure gauge, calibrated pressure sensors and a current meter, and include open ports for additional sensors. A fourth broadband seismometer and strong motion accelerometer will be added to an existing science junction box at another site on the shelf. Together with the seismometers and pressure gauges already on the OOI RCA at the Slope Base and Southern Hydrate Ridge sites, this infrastructure will form a pioneering “critical mass” offshore geophysical observatory to study fault coupling and deformation of the Cascadia megathrust and the overlying accretionary prism across a ~100 km section offshore and support efforts to prototype offshore earthquake and tsunami early warning.
Session: Marine Seismoacoustics [Poster Session]
Type: Poster
Date: 5/1/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: William
Student Presenter: No
Invited Presentation:
Authors
William Wilcock Presenting Author Corresponding Author wilcock@uw.edu University of Washington |
Michael Harrington mikeh77@uw.edu University of Washington |
David Schmidt dasc@uw.edu University of Washington |
Deborah Kelley dskelley@uw.edu University of Washington |
Harold Tobin htobin@uw.edu University of Washington |
Marine Denolle mdenolle@uw.edu University of Washington |
Mika Thompson usherm42@uw.edu University of Washington |
Geoffrey Cram cramg@uw.edu University of Washington |
Amanda Labrado all91@uw.edu University of Washington |
Dana A Manalang manalang@uw.edu University of Washington, Seattle, Washington, United States |
Chuck McGuire chuckmcg@uw.edu University of Washington, Seattle, Washington, United States |
James W Tilley jtilley@uw.edu University of Washington, Seattle, Washington, United States |
Mark A Zumberge mzumberge@ucsd.edu University of California, San Diego, La Jolla, California, United States |
Glenn S Sasagawa gsasagawa@ucsd.edu University of California, San Diego, La Jolla, California, United States |
Implementation Plan for the Cascadia Offshore Subduction Zone Observatory
Category
Marine Seismoacoustics