While we don't expect another tsunami anytime soon, and the town of Valdez has been moved to a more tsunami friendly location, here is some information to be aware of, as tsunami's are still a possibility in Valdez. Every Wednesday evening at 5pm the tsunami siren is tested. If you are to hear the tsunami at other times you should immediately head to high ground. In most cases in town head to the high school. If further out of town go to the airport. Or if you're past Valdez Glacier Stream travel out the highway past Robe Lake (six mile marker on the Richardson Highway). If out Dayville Road and a tsunami is in sight head up the hillside, otherwise go past 6 mile on the Richardson Highway.
The adjacent map shows expected levels of tsunami encroachment to Valdez depending on the type of tsunami.
Yellow is the current highest high tides. Scenario's 1-6 signify an underwater sluff of shelf falling into deeper waters. Scenario's 13-15 are typical fault slips occurring in Prince William Sound or the Gulf of Alaska.
March 27, 1964, The Mw9.2 Alaska earthquake of 5:36 p.m. March 27, 1964, at Valdez was characterized by a strong, rapid, rolling motion lasting from three to five minutes, during which people had great difficulty standing. The ground surface was heaving and subsiding like a swell in the open ocean, except more frequent and rapid. The great disaster during the earthquake happened in the dock and harbor area, where a massive submarine landslide generated a tsunami, inundating the waterfront up to two blocks inland. The slide and slide-generated waves were responsible for the deaths of 30 people at the city dock. Two men were killed by falling cargo and another died because of a heart attack.
The second wave crossed the waterfront 10–15 minutes after the first wave, carrying a large amount of the debris.