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State of Alaska Alaska / Natural Resources DNR / Geological & Geophysical Surveys DGGS / Geologic HazardsHazards / Barry Arm LandslideBarry Arm

Barry Arm Landslide and Tsunami Hazard

Status Update: July 12, 2024

  • The interagency science team reports that the Barry Arm landslide is currently showing no indications of large-scale, widespread movement. Smaller-scale instabilities on the surface of the landslide still pose a threat of localized tsunami generation in Barry Arm. Mariners transiting near Barry Arm should remain vigilant.
  • For more information on monitoring activities, equipment and data availability, please visit https://landslides.usgs.gov/storymap/barry-arm/.
  • This page will be updated on August 2, 2024, or earlier if the threat level changes.
  • Previous updates have been archived here.

Recent Fieldwork

  • DGGS/USGS staff deployed infrasound and seismic sensors in Yale Arm fjord for short-term surveillance
  • DGGS/USGS performed routine maintenance on weather stations and other instrumentation in Barry Arm fjord
  • DGGS/USGS performed a helicopter-borne ice-penetrating radar survey on Barry Glacier to measure the thickness and internal structure of the glacier

Upcoming Public Events - July/August 2024

  • none

Current Landslide Status

An ongoing landslide and landslide-generated tsunami threat exists in Barry Arm, northwestern Prince William Sound, Alaska. The landslide is stable or exhibiting slow rates of deformation (<50 mm/d). Localized areas of higher velocities may be evident, but movement is largely surficial. While potential failure of these areas may result in a localized tsunami, failure is unlikely to represent a region-wide tsunami threat. Partial or catastrophic rapid failure is unlikely without external forcing, such as that associated with a strong regional earthquake. "Small" but infrequent rockfalls and shallow landslides may be commonly observed.

Mariners should remain vigilant when in the vicinity of Barry Arm or nearby waters and be prepared to depart the area if any unusual rockfall activity is seen or heard, or if unusual waves, currents, or tides are observed.


(Last updated February 2, 2024)

The Barry Arm landslide is a large (~500 M m3 or 650 M yd3) landslide located in the northwestern corner of Prince William Sound, Alaska. Rapid failure of the landslide has the potential to create a tsunami that results in life-threatening waves and currents in Barry Arm, Harriman Fjord, Port Wells and adjacent fjords. The existence of the landslide is evident in photographs dating back to at least 1935, with possible evidence of the landslide in photographs dating to 1913.

Throughout the observational record, the Barry Arm landslide has experienced slow movement punctuated by episodes of acceleration. While slow downslope movement is both common and expected, rapid increases in the rate of movement may be a possible precursor to catastrophic failure. As such, observations and hazard messages are often centered around trends in the observed rates of downslope movement at Barry Arm, as measured by ground-based, aerial, and satellite surveillance methods.

The Barry Arm landslide is being monitored by a multiagency team of scientists from the U.S. Geological Survey (USGS), National Tsunami Warning Center (NTWC), Alaska Division of Geological & Geophysical Surveys (DGGS), and the University of Alaska Fairbanks Alaska Earthquake Center (AEC). For more information on monitoring activities, equipment and data availability, please visit https://landslides.usgs.gov/storymap/barry-arm/.

Continuity of Operational Monitoring Network

(Last updated February 2, 2024)

Scientists at USGS, DGGS, AEC, and NTWC will continue to make every effort to minimize outage of this critical network of sensors. The Alaska environment and its inhabitants can wreak havoc on our sites: strong winds can damage sensors, power components, and antenna; deep snow can bury instruments and solar panels and makes it difficult to access (and even find) sites, rain can work its way into sensitive electronics, and our four-legged neighbors, such as bear, deer, and goats, have a taste for our wiring and enclosures. While we have made our best effort to harden the sensors, power systems, and telemetry for continuous operation of the equipment and to resist weather and animals, it is necessary to have reasonable expectations given the difficulties of working in this harsh environment. Reasonable expectations include:

  • Safety of the scientists and engineers who maintain the systems is paramount. Poor weather conditions may prevent us from traveling to Barry Arm via helicopter or boat for immediate repair and restoration of system functionality.
  • Prolonged outage of one or more sensors is possible. All efforts will be made to keep equipment operating throughout the year. However, high winds, deep snow, and other hazards such as snow avalanches and rockfall may prevent us from fixing instruments even if we are able to reach the sites.
  • Deep snow, evolving snowpack, and variable atmospheric conditions make it difficult to precisely measure landslide deformation. As such, our ability to inform the public about landslide movement is significantly diminished during winter or when clouds or rainfall obscure the view from the air or space.

Instrumentation Status

Monitoring Method Agency Operational Status Notes
Water Level NTWC Online  
Seismic - BAE AEC Online  
Seismic - BAT AEC Online  
Infrasound - BAEI USGS Online  
Infrasound - WHTR USGS Offline, Permanently Decommissioned Decommissioned as of 24 November 2023
Ground-Based Radar USGS Online  
Deformation camera USGS Online  
Satellite InSAR and imagery USGS Online  
Hydrometeorology - BAE DGGS Online  
Hydrometeorology - BAW DGGS Online  
Hydrometeorology - Mt Doran DGGS Online  

Next Update

This message will be updated on August 2, 2024, or earlier if the threat level changes. For more information, please see our Barry Arm Summary Information & FAQ page.

Contact Information

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Email here for general questions

Dennis Staley
Research Physical Scientist
U.S. Geological Survey - Alaska Volcano Observatory

Martin Larsen
Landslide Hazards Program Coordinator
Division of Geological & Geophysical Surveys

Michael West
State Seismologist
Alaska Earthquake Center

Dave Snider
Tsunami Warning Coordinator
National Tsunami Warning Center

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