TSUNAMI HAZARD MITIGATION FOR ALASKA

Coastal Alaska lives with the most serious tsunami risk in the United States. Historically, tsunamis generated by earthquakes in Alaska have caused damage and loss of life along the West Coast and across the Pacific. Here in Alaska, though, tsunamis generated by nearby earthquakes represent “near-field” hazards. In other words, people have minutes rather than hours to reach safety.

The Earthquake Center works to make our coastal communities safer by providing state and local officials with the best possible information for addressing the tsunami hazards faced by their communities.

Click on the map at right to explore our interactive mapping interface. Zoom to your area of interest by selecting a community and map type. You can also toggle between map and satellite views at the top right. At present, the interactive map includes flow depths and inundation boundaries for 21 at-risk communities.

INUNDATION MAPPING PROJECT

In partnership with the Alaska Division of Geological and Geophysical Surveys and the Alaska Division of Homeland Security and Emergency Management, we evaluate and map potential inundation using numerical modeling of tsunami wave dynamics.

Communities are selected with consideration to their tsunami hazard exposure, location, infrastructure, availability of data, and willingness to incorporate the results in a comprehensive mitigation plan. The maps incorporate the best tsunami science available at the time of publication.

PUBLISHED REPORTS MAPPING UNDERWAY

IN PUBLICATION

  • Homer and Seldovia

IN REVIEW

  • Andreanof Islands
  • Adak and Atka
  • Anchor Point, Port Graham and Nanwalek
  • Bristol Bay and Pribilof Islands
  • False Pass and Perryville
  • Kodiak Region
  • Port Alexander, Craig and Ketchikan
  • Shemya

IN PREPARATION

  • Kasaan, Klawock, Metlakatla, Pelican, Point Baker and Point Protection

 

Click to enter interactive tsunami inundation mapping interface

Tsunami News

Lituya Bay

A flying boat dropped Paddy Sherman’s mountaineering expedition at Lituya Bay on June 17, 1958. Over the next three weeks, the climbers made the second ascent of Mount Fairweather, a first ascent of an unnamed peak, and had come within 200 feet of the first ascent of Mount Lituya. When hot weather made glacier travel untenable, they returned to Lituya Bay and radioed a request to be picked up on July 10.

Lituya Bay offers the only sheltered anchorage for a long stretch of Southeast Alaska coast, but the bay itself is hardly safe. Cenotaph Island, a large wooded mound at the center of the bay, is named for the 21 members of the La Perouse expedition who drowned in 1798 after capsizing in the tidal bore at the bay’s shallow entrance.

Pedestrian Travel Time Maps

For communities that have well-defined tsunami scenarios, it is possible to estimate the amount of time required to evacuate to high ground. These models assume evacuation by foot and include complications such as ground cover, steep terrain, and other barriers identified by the community. The full methodology is described in this overview white paper.

Maritime Response Guidance Documents

Maritime response guidance documents for the following communities:

provide response guidance in the event of tsunamis for small vessels such as recreational sailing and motor vessels, and commercial fishing vessels. The developed documents follows the draft guidance developed by the National Tsunami Hazard Mitigation Program (NTHMP) and are based on anticipated effects of a maximum-considered distant and locally generated tsunami event.