Search for: All records

## Kamchatka M8.8 Earthquake and Tsunamis Reach Across the Pacific to NSF’s OOI Regional Cabled Array   Deborah Kelley1, Joe Duprey1, Wendi Ruef1, and W. Chadwick2   1University of Washington, 2Oregon State University   On July 29 at 23:24:52 UTC, a powerful magnitude 8.8 earthquake struck the Kamchatka Peninsula in Russia, unleashing seismic energy and a tsunami that surged across the Pacific Ocean. This extraordinary event was captured in remarkable detail by the NSF Ocean Observatories Initiative’s (OOI) Regional Cabled Array—a seafloor observatory located offshore Oregon and Washington and one of the world’s most advanced underwater monitoring networks, with over 150 instruments transmitting real-time data to shore at the speed of light.   At 23:33:15, the seismic waves from the Kamchatka earthquake reached Axial Seamount, located nearly 300 miles west of the Oregon coast and almost a mile beneath the ocean’s surface, having crossed the entire Pacific in just nine minutes. The vibrations were so intense they rattled a seafloor instrument continuously for over four hours (a,b).   Then, at 06:03:00 UTC on July 30—6 hours and 30 minutes after the quake—the first tsunami waves arrived at Axial Seamount (c). Ultra-sensitive pressure sensor on bottom pressure tilt instruments picked up the waves with astonishing clarity. Lower-resolution sensors across the array also tracked the tsunami’s journey toward the UW west coast. Racing at speeds of 270 miles per hour, the first wave swept across the Juan de Fuca Plate and over the Cascadia Subduction Zone, eventually reaching seafloor monitoring instruments at the Oregon Shelf site just 14 miles offshore from Newport, Oregon. The OOI Regional Cabled Array instruments showed that the Pacific Ocean reverberated with smaller waves for several days after the first tsunami waves arrived—echoes of one of the most powerful seismic events ever recorded.   This event highlights not only the dynamic nature of our planet and the seismic and tsunami hazards that we have to be prepared for in the Pacific Northwest, but also the incredible capability of modern science to observe and understand these kinds of events—in real time from deep beneath the ocean’s surface, and the value of such monitoring to coastal communities.   ## Bottom Pressure and Tilt Meter Notes BOTPT LILY tiltmeter data (csvs) are curated by William Chadwick. The tilt units are microradians, or µrad.   BOTPT-MJ03F-BPR-29July-to-01Aug2025-15sec.csv Date/Time, Pressure (psi) with tides, De-tided Depth (m) - from 29 July @ 00:00 to 01 August @ 00:00, and a record every 15 seconds (from the NANO bottom pressure sensor)   BOTPT-MJ03F-LILY-tilt-data-29-30July2025-01sec.csv Date/Time, X-tilt, Y-tilt - from 29 July @ 00:00 to 30 July @ 23:13, and a record every 1 second (from the LILY tiltmeter)   ## Where to find Additional Data Additional data from the included sensors prior to and after the event, or from OOI's many co-located sensors can be obtained through the OOI data portal https://ooinet.oceanobservatories.org/ , the OOI data explorer https://dataexplorer.oceanobservatories.org/ or OOI's M2M API service https://oceanobservatories.org/m2m/.   ## Contact Information jduprey@uw.edu   This material is based upon work supported by the Ocean Observatories Initiative (OOI), a major facility fully funded by the US National Science Foundation under Cooperative Agreement No. 2244833, and the Woods Hole Oceanographic Institution OOI Program Office. 

Abstract Distributed acoustic sensing (DAS) on submarine fiber-optic cables is providing new observational insights into solid Earth processes and ocean dynamics. However, the availability of offshore dark fibers for long-term deployment remains limited. Simultaneous telecommunication and DAS operating at different wavelengths in the same fiber, termed optical multiplexing, offers one solution. In May 2024, we collected a four-day DAS dataset utilizing an L-band DAS interrogator and multiplexing on the submarine cables of the Ocean Observatory Initiative’s Regional Cabled Array offshore central Oregon. Our findings show that multiplexed DAS has no impact on communications and is unaffected by network traffic. Moreover, the quality of DAS data collected via multiplexing matches that of data obtained from dark fiber. With a machine-learning event detection workflow, we detect 31 T waves and the S wave of one regional earthquake, demonstrating the feasibility of continuous earthquake monitoring using the multiplexed offshore DAS. We also examine ocean waves and ocean-generated seismic noise. We note high-frequency seismic noise modulated by low-frequency ocean swell and hypothesize about its origins. The complete dataset is freely available. 

Vigorous seepage offshore Oregon provides insight into the relationship between margin permeability and megathrust slip behavior. 

The unique ecosystems and biodiversity associated with mid-ocean ridge (MOR) hydrothermal vent systems contrast sharply with surrounding deep-sea habitats, however both may be increasingly threatened by anthropogenic activity (e.g., mining activities at massive sulphide deposits). Climate change can alter the deep-sea through increased bottom temperatures, loss of oxygen, and modifications to deep water circulation. Despite the potential of these profound impacts, the mechanisms enabling these systems and their ecosystems to persist, function and respond to oceanic, crustal, and anthropogenic forces remain poorly understood. This is due primarily to technological challenges and difficulties in accessing, observing and monitoring the deep-sea. In this context, the development of deep-sea observatories in the 2000s focused on understanding the coupling between sub-surface flow and oceanic and crustal conditions, and how they influence biological processes. Deep-sea observatories provide long-term, multidisciplinary time-series data comprising repeated observations and sampling at temporal resolutions from seconds to decades, through a combination of cabled, wireless, remotely controlled, and autonomous measurement systems. The three existing vent observatories are located on the Juan de Fuca and Mid-Atlantic Ridges (Ocean Observing Initiative, Ocean Networks Canada and the European Multidisciplinary Seafloor and water column Observatory). These observatories promote stewardship by defining effective environmental monitoring including characterizing biological and environmental baseline states, discriminating changes from natural variations versus those from anthropogenic activities, and assessing degradation, resilience and recovery after disturbance. This highlights the potential of observatories as valuable tools for environmental impact assessment (EIA) in the context of climate change and other anthropogenic activities, primarily ocean mining. This paper provides a synthesis on scientific advancements enabled by the three observatories this last decade, and recommendations to support future studies through international collaboration and coordination. The proposed recommendations include: i) establishing common global scientific questions and identification of Essential Ocean Variables (EOVs) specific to MORs, ii) guidance towards the effective use of observatories to support and inform policies that can impact society, iii) strategies for observatory infrastructure development that will help standardize sensors, data formats and capabilities, and iv) future technology needs and common sampling approaches to answer today’s most urgent and timely questions.