The Cascadia Offshore Subduction Zone Observatory Infrastructure Project
Description:
This summer, the Cascadia Offshore Subduction Zone Observatory (COSZO), an NSF-funded infrastructure project, will add seismic and geodetic instruments to the Ocean Observatories Initiative (OOI) Regional Cabled Array (RCA) off Newport, Oregon. In Cascadia, geophysical observations show that the megathrust is mostly locked from the coastline to the deformation front, but off central Oregon they are consistent with a locked megathrust near the deformation front that transitions to creeping behavior beneath the shelf where there are two sustained clusters of earthquakes. We are constructing new science junction boxes, with updates to the RCA design, to connect to three primary nodes on the continental slope and shelf that currently do not support seafloor geophysical observations. At each new junction box and a fourth site on the shelf, we will install a Nanometrics Atlantis Cabled Observatory ocean bottom seismic package comprising a buried broadband seismometer, a strong-motion accelerometer, a low-frequency hydrophone, and a differential pressure gauge. We are building two types of calibrated absolute pressure gauges that utilize Paroscientific resonant quartz crystal sensors. The Geodetic and Seismic Sensor Module combines a triaxial accelerometer with two pressure gauges that are periodically calibrated against the internal pressure of the housing measured by a barometer. The Self-Calibrating Pressure Recorder also includes two pressure gauges but performs calibrations with a reference pressure close to ambient generated by a piston gauge. COSZO will also include uncalibrated absolute pressure gauges, Nortek Vector 3-component ocean current meters, and open ports for more sensors. Together with sensors already on the OOI RCA at the Slope Base and Hydrate Ridge sites, the infrastructure will enable studies of fault coupling and deformation of the Cascadia megathrust and the overlying accretionary prism and support efforts to prototype offshore earthquake and tsunami early warning. COSZO will stream data into EarthScope Data Services and a workshop is planned for spring 2027 to engage early career scientists.
Session: Linking Subduction Zone Processes and Cascading Hazards in Alaska, Cascadia, Chile and Beyond [Poster]
Type: Poster
Date: 4/16/2026
Presentation Time: 08:00 AM (local time)
Presenting Author: Mika Thompson
Student Presenter: No
Invited Presentation:
Poster Number: 134
Authors
Mika Thompson Presenting Author Corresponding Author usherm42@uw.edu University of Washington |
William Wilcock 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 |
Geoffrey Cram cramg@uw.edu University of Washington |
Matthew Khoo mattkhoo@uw.edu University of Washington |
Amanda L Labrado all91@uw.edu University of Washington, Seattle, Washington, United States |
Dana A Manalang manalang@uw.edu University of Washington, Seattle, Washington, United States |
Chuck McGuire mcguire@apl.washington.edu University of Washington, Seattle, Washington, United States |
Kira Smith kiras21@uw.edu University of Washington, Seattle, Washington, United States |
James W Tilley jtilley@uw.edu University of Washington, Seattle, Washington, United States |
Mark Zumberge mzumberge@ucsd.edu University of California, San Diego, La Jolla, California, United States |
Glenn Sasagawa gsasagawa@ucsd.edu University of California, San Diego, La Jolla, Washington, United States |
The Cascadia Offshore Subduction Zone Observatory Infrastructure Project
Category
Linking Subduction Zone Processes and Cascading Hazards in Alaska, Cascadia, Chile and Beyond