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The Mount Rainier Lahar Detection System: Risk Mitigation for an Unlikely, but Potentially Catastrophic, Event

Description: 

Mount Rainier (Washington, USA) last erupted ~1,000 years ago and has experienced tens of eruptions over the last 10,000 years. Of all the hazards associated with Mount Rainier, large lahars pose the greatest risk to communities downstream of the volcano—more than 90,000 people live in areas that could be impacted by a future large lahar. Large lahars have reached as far as the Puget Lowlands (> ~50km) at least 11 times over the last 6,000 years. All but one was associated with an eruption; the exception is the ~1507 A.D. landslide-initiated Electron Mudflow, for which no evidence of an associated eruption has been found. Recent studies show that the western flank of Mount Rainier could produce future non-eruptive landslides and associated large lahars down the Puyallup and/or Tahoma Creek drainages, potentially reaching nearby small towns within 5-10 minutes and larger communities within 60 minutes.

The Mount Rainier Lahar Detection System is part of a risk-mitigation strategy pursued by a group of local, State, and Federal agencies since 1998. It consists of several components: 1) a real-time network of tens of seismometers, infrasound arrays, tripwires, webcams, and other instruments located on the flanks of the volcano and along vulnerable drainages operated and upgraded periodically by the U.S. Geological Survey (USGS) Cascades Volcano Observatory (CVO) and the Pacific Northwest Seismic Network; 2) an automated detection system, designed and maintained by CVO, that triggers alarms in two separate county- and State-run 24/7 emergency operations centers; and 3) a set of protocols and inter-agency agreements among CVO, Pierce County (Washington) Department of Emergency Management, and the Washington State Emergency Management Division that delineate each agency’s detection, alerting, and/or warning responsibilities, protocols that are reviewed and tested periodically. CVO’s protocols have required establishing a rotation of scientists who carry a duty phone to provide partners with a 24/7 point of contact, and who are expected to respond within 1-2 minutes to automated alerts from the detection system.

Session: Detecting, Characterizing and Monitoring Mass Movements - I

Type: Oral

Date: 5/2/2024

Presentation Time: 08:15 AM (local time)

Presenting Author: Seth

Student Presenter: No

Invited Presentation: 

Authors