Study finds ‘rare but real risk’ of tsunami threat to parts of Alaska’s largest city

ANCHORAGE, Alaska — Researchers have concluded there’s a “uncommon however actual threat” that an earthquake-produced tsunami may inundate components of coastal Anchorage underneath sure circumstances, a newspaper reported, a shift from the prior understanding of the chance posed to Alaska’s largest metropolis.

Beforehand, researchers mentioned the shallow waters of Higher Prepare dinner Inlet would work to decrease the ability of a tsunami wave. However that was not primarily based on scientific modeling, mentioned Elena Suleimani, an creator of the report and a tsunami modeler with the Alaska Earthquake Middle, the Anchorage Day by day Information reported.

“Up till now, our understanding of the chance or stage of hazard publicity was simply anecdotal,” Suleimani mentioned.

The findings from the examine by the College of Alaska Fairbanks and the Alaska Division of Geological and Geophysical Surveys — launched Wednesday — stem from a first-time effort to mannequin potential tsunami impacts on Anchorage primarily based on varied earthquake situations, based on the newspaper.

“A uncommon mixture of earthquake magnitude, location, and timing have to be happy for tsunami wave power to achieve higher Prepare dinner Inlet coincident with a pure excessive tide,” the examine states.

A part of the reasoning for the idea that Anchorage was not inclined was that in a magnitude 9.2 earthquake in 1964, there was no remark of a tsunami within the metropolis, the researchers mentioned. However they discovered by way of modeling that the earthquake did produce a 10-foot (3-meter) tsunami — one which went unnoticed as a result of it arrived at 2 a.m. throughout a minus-16-foot (minus-4.9-meter) low tide that resulted within the water stage staying under regular excessive tide ranges.

The modeling of future tsunami potential for Anchorage evaluates hypothetical conditions involving a quake above 8.5 in magnitude.

A possible worst-case state of affairs would largely have an effect on park land and infrastructure, such because the port, but additionally may have an effect on some waterfront houses, mentioned Amanda Loach, director of Anchorage’s emergency administration workplace. The dynamics of Higher Prepare dinner Inlet are such {that a} harmful wave would most likely be hours away, so individuals might be warned upfront, she mentioned.

Town and state plan to work on a plan to deal with the chance, Loach mentioned. Residents shouldn’t be alarmed by the report however ought to take into consideration preparedness, she mentioned.