Geologists say section of Aleutian Islands could send devastating tsunami to Hawaii
  • Wednesday, June 19, 2019
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Geologists say section of Aleutian Islands could send devastating tsunami to Hawaii

  • COURTESY PACIFIC TSUNAMI MUSEUM

    Men run from a tsunami in downtown Hilo in 1946. An earthquake in the eastern Aleutians generated the tsunami that killed 159 people in Hawaii.

ANCHORAGE, Alaska >> Geologists in Alaska have found evidence that a 125-mile section of the eastern Aleutian Islands that was once considered unlikely to generate earthquakes may be a future source of temblors — as well as potentially devastating tsunamis that could hit Hawaii.

Field work by U.S. Geological Survey scientists on Sedanka Island near Dutch Harbor, a major U.S. fishing port, revealed “sand sheets,” or deposits of sand lifted off beaches and moved a half-mile inland. The sand sheets indicate large tsunamis had hit frequently — in geologic time.

“This is the first Aleutian study to report evidence for prehistoric tsunamis, and the recurrence intervals are in geologic perspective very short at 300 to 340 years,” said USGS geologist Rob Witter.

The Aleutians, stretching about 1,200 miles, are part of a subduction zone where two great tectonic plates collide. The Pacific Plate, beneath the Pacific Ocean, is slowly being subducted, or pushed below, the North American Plate that covers most of North America.

Prevailing models show that friction locks up the two plates, and elastic energy builds until the strain is too great and there’s an earthquake. The largest releases in the form of megathrust earthquakes shift hundreds of miles of earth and create devastating tsunamis.

A 1946 earthquake 90 miles south of Unimak Island in the eastern Aleutians stopped before it reached the area near Dutch Harbor. The earthquake created a tsunami that killed six people in Alaska, including five Coast Guardsman at a lighthouse on Unimak Island, and 159 people in Hawaii.

A 1957 quake tore 745 miles of ground near Adak in the western Aleutians but stopped short of the area around Dutch Harbor. A tsunami took no lives but caused widespread damage in Hawaii.

The 125-mile-long area in the eastern Aleutians has been an enigma, Witter said. It was thought to be over a “creeping” fault where the plates move continuously without building up strain.

A tip from a retired Humboldt State University geologist, Gary Carver, who saw sand sheets on Sedanka Island led to the study by Witter and other researchers. The oldest sand sheet appeared to be deposited 1,700 years ago. The newest was deposited in 1957.

“In this particular area, what’s surprising is that it’s creeping, yet we have evidence for large tsunamis that may have been caused by megathrust earthquakes in the past,” Witter said.

The USGS researchers made no recommendations for earthquake modeling affecting Hawaii, but officials there have used the information to broaden tsunami evacuation zones, Witter said.

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  • Just like the tee shirt says. If can, can. If no can, no can. We could add this one. If the Earthquake comes, it comes. If the Earthquake doesn’t come, it doesn’t come.

  • More of a reason to take life one day at a time. Hug your kids. Thank a veteran. Donate to a good cause. That’s all we have control over. The rest is up to the Man upstairs.

    • Indeed. And keeping it off the main news would stop raving lunatics like Winston from blaming this on Obama like he does everything that ever goes wrong in the history of mankind.

      • lol…so true. He was even hollering that Obama caused 9-11 the other day. Truth is, Bush was asleep and had ignored all the warnings before 9-11 and never really paid a political price for it.

        • In case you didn’t know, the attack was planned and set up during the Clinton years. Bush messed up, but so did Clinton. He lobbed rockets at Osama when the Monica thing was blowing up.

        • Republican Senator Lindsey Graham has come out saying the dislike and hate that many Republicans have for Obama is not logical and is unhealthy.

          We can see that with Thos, Ronin, Winston, hawaiikone and others in how they refuse to take ANY personal responsibility for anything in their lives, instead blaming Obama for everything they can. They don’t care it makes them look completely insane and completely infantile.

        • Want to point out where I say things that are wrong? Or are you just going to snipe like Thos because you know you simply will never win a substance-fact based argument with me ever?

        • hawaiikone, perhaps you need to seek professional help as you are part of the group that blames Obama for you being late to the bus because you took too long on the toilet?

          Take some personal responsibility for ONCE in your life. Pathetic you are.

        • choyd, no other commenter I’m aware of repetitively denigrates other posters when they’re not even involved in a discussion. I find that repulsive. Obama? I voted for him at one time, but disliked many of his actions, just as Bush had disappointed me often as well. Does that qualify me as a hater? Devoid of any responsibility? Ludicrous. Your contentious style falls more in line with that label, well evidenced by your initial comment today.

        • Want to show me where I ever blamed Bush for something he wasn’t responsible for?

          Let’s just face it Thos, you cannot provide a substance based rebuttal to anything I say. Hence why you make snide sniping comments because that is all you have.

          And let’s not forget that Obama got blamed for the weather resulting in flooding in Texas here. Apparently Obama has magical powers controlling the weather.

          You and your friends are cancers upon America and should be deported and have your citizenship revoked.

  • What is the point of that headline? What are we supposed to do, quiver in fear for a wave that may come sometime in the next 100 years?
    These guys are just angling for more funding so they can play in the dirt and rocks.

  • its wierd… but i always have a recurring dream about tsunamis… like incredibly enormous ones coming towards me… but alway wake up before it hits.

    my brother also has the same recurring dreams…

  • Why worry about something you can do nothing about? Just don’t live near the shore if it bothers you. You’re more apt to get killed in a car accident or run over by a pimply skateboarder.

  • C’mon, really? In other news, Astronomers say that one day the earth will be hit by a rogue meteor that will end life as we know it…including Hawaii. How come you guys don’t put that in the paper to fill space.

  • I’ve got to say with all the incredibly horrific crap going on in the world, children starving, anarchy prevalent in some areas where the populations are being gunned down, the devastating effects of nature (global warming) you’d think that this ‘Newspaper’ would concern itself with some valid news….stories that inform and even inspire others to rise up and perhaps do something constructive……this fortune telling nonsense, mystical ‘what if’s ‘ is not worthy of a metropolitan newspaper…hell its hardly worthy of a passing conversation over a cup of coffee. Star Advertiser…get busy with the news, lets find out why our roads are in such a deplorable condition, why our local politicians are doing so well financially while the we have set records nationally for the number of homeless in our state!

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