# Could a giant killer tsunami hit the west or east coast of the US? **URL:** \ **Category:** Factual Questions\ **Created:** [December 29, 2004, 9:42pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156 "2004-12-29T21:42:35Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Green\_Cymbeline](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/green_cymbeline/32/9244_2.png) [@Green\_Cymbeline](https://boards.straightdope.com/u/Green_Cymbeline)\ **Post date:** [December 29, 2004, 9:42pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/1 "2004-12-29T21:42:35Z")
Could something like what happened to south Asia happen to either of our shores? Are there similar tectonic areas in the right part of the ocean that could cause an earthquake sparking a tsunami that would be directed towards us? ---
**Author:** ![Reeder](https://avatars.discourse-cdn.com/v4/letter/r/c6cbf5/32.png) [@Reeder](https://boards.straightdope.com/u/Reeder)\ **Post date:** [December 29, 2004, 9:53pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/2 "2004-12-29T21:53:13Z")
A big enough quake in any part of the Pacific Ocean could generate tsunami’s that could affect the west coast. > [@](#): > > Earthquake Activity > Typical activity along the Pacific Coast from Southern California to Alaska and Hawaii, the most significant was a magnitude 4.4 event near Rat Island in the Aleutians. > > On October 15 2004, at 12:09 a.m., EDT, a 6.7 magnitude earthquake on the Richter Scale occurred in the Taiwan region (24.6 N / 122.7 E) 75 miles east-southeast of Taipei. No damage or injuries were reported and the earthquake was not sufficient to generate a damaging tsunami for the US west coast. (US Department of the Interior/US Geological Survey) [http://www.fema.gov/emanagers/2004/nat101504.shtm](http://www.fema.gov/emanagers/2004/nat101504.shtm) That was from off Taiwan. ---
**Author:** ![cher3](https://avatars.discourse-cdn.com/v4/letter/c/da6949/32.png) [@cher3](https://boards.straightdope.com/u/cher3)\ **Post date:** [December 29, 2004, 9:53pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/3 "2004-12-29T21:53:55Z")
Apparently, if you are counting Alaska as West Coast: [http://www.drgeorgepc.com/Tsunami1964PrWilliam.html](http://www.drgeorgepc.com/Tsunami1964PrWilliam.html) ---
**Author:** ![El\_Cid\_Viscoso](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@El\_Cid\_Viscoso](https://boards.straightdope.com/u/El_Cid_Viscoso)\ **Post date:** [December 29, 2004, 9:54pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/4 "2004-12-29T21:54:36Z")
Tectonic issues are inevitable, but they aren’t the only concern. You might want to visit [this thread](http://boards.straightdope.com/sdmb/showthread.php?t=293790) for a view on what many consider to be the most evident impending tsunami threat to the US East Coast, Africa and Western Europe. ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [December 29, 2004, 9:58pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/5 "2004-12-29T21:58:17Z")
Seattle is known to be vulnerable. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [December 29, 2004, 10:24pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/6 "2004-12-29T22:24:29Z")
Short answer: Yes, for both coasts. But it’s not terribly likely at any given time. Longer answer: Tsunamis affecting the Pacific Coast of Asia and its extension through island chains and such down to New Zealand will affect Pacific North America – but appear often to “peter out” as they cross that vast expanse of ocean. Ones closer to home could cause serious tsunami damage, but are less likely to occur, except where they would impact Alaska, as the area which might generate them is less stressed and therefore less apt to have an earthquake at any given time. Most of the earthquake-prone area at the intersection of the Pacific and North American plates is on land. However, where this tails off to the south, it’s out to sea and could cause serious tsunami damage to places like Mazatlan and Acapulco on the Mexican Pacific coast. Since the Atlantic coast is predominantly passive-margin coast bordering a spreading plate boundary, as opposed to the colliding ones along the Pacific, tsunami-causing temblors are much less likely – but the potential is there. Another GQ thread addresses the potential for catastrophic tsunamis from the Canary Islands; both North Carolina and Newfoundland are at some risk from subsidences along the continental slope off their coasts, with other areas in somewhat less danger. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [December 30, 2004, 12:53am UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/7 "2004-12-30T00:53:31Z")
Yes, there appears to be evidence of multiple tsunamis in northern California, estimated intervals of 700 years approximately. Ditto Washington, Oregon, British Columbia, and Alaska. Also, there currently is the possibility of a big landslide in the steep submarine canyons off Santa Cruz that could cause serious problems on the shores from Monterey to San Francisco. And there is discussion of a huge landslide capability in the Canary Islands that would devastate Atlantic shores. And these are just the ones I happen to have heard about. ---
**Author:** ![SpoilerVirgin](https://avatars.discourse-cdn.com/v4/letter/s/4491bb/32.png) [@SpoilerVirgin](https://boards.straightdope.com/u/SpoilerVirgin)\ **Post date:** [December 30, 2004, 1:23am UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/8 "2004-12-30T01:23:36Z")
There’s an excellent [article](http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2004/12/29/MNG7VAIDVC1.DTL) on SFGate today about the possibility of a tsunami hitting Northern California. > [@](#): > > If a magnitude 9.0 shallow earthquake struck the Pacific Northwest today, it “would most probably generate a large local tsunami that would attack Oregon, Washington, (California and Canada) within minutes to an hour,” said a leading tsunami scientist, Laura Kong, of UNESCO’s International Tsunami Information Centre in Honolulu. There’s also a [picture](http://www.sfgate.com/cgi-bin/object/article?f=/c/a/2004/12/29/MNG7VAIDVC1.DTL&o=0) of the devastation caused by a tsunami in Crescent City in 1964. ---
**Author:** ![Gulo\_gulo](https://avatars.discourse-cdn.com/v4/letter/g/bcef8e/32.png) [@Gulo\_gulo](https://boards.straightdope.com/u/Gulo_gulo)\ **Post date:** [December 30, 2004, 5:47am UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/9 "2004-12-30T05:47:07Z")
> [@](#): > > There’s also a picture of the devastation caused by a tsunami in Crescent City in 1964. From the same earthquake: some [photos](http://www.drgeorgepc.com/Tsunami1964Canada.html) of the tsunami damage in Port Alberni, BC. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [December 30, 2004, 6:33am UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/10 "2004-12-30T06:33:11Z")
From [The Pacific Northwest Seismograph Network](http://www.pnsn.org/HAZARDS/CASCADIA/cascadia_event.html) > [@](#): > > Between 9:00 PM and 10:00 PM, local time, on January 26th 1700, a great earthquake shook the Pacific Northwest. This quake, with magnitude estimated at 9.0, rocked the region with strong shaking for several long minutes minutes while coastal Washington plummeted as much as 1.5 meters relative to coastal waters. > [@](#): > > Tsunami Traces > Uncharacteristic sand deposits in Washington’s coastal soil give evidence of local tsunamis. BTW, the exact date of the earthquake comes mainly from Japanese tsunami records, so a sufficiently powerful quake off the coast of Asia could cause a tsunami on this side of the Pacific. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [December 30, 2004, 11:12am UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/11 "2004-12-30T11:12:38Z")
See [this thread](http://boards.straightdope.com/sdmb/showthread.php?t=293790). It’s the east coast that could get _really_ flattened. It could happen in 10 years, or in 100 years, or 1,000 years, or never. That’s Nature for you. ---
**Author:** ![CynicalGabe](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@CynicalGabe](https://boards.straightdope.com/u/CynicalGabe)\ **Post date:** [December 30, 2004, 1:08pm UTC](https://boards.straightdope.com/t/could-a-giant-killer-tsunami-hit-the-west-or-east-coast-of-the-us/282156/12 "2004-12-30T13:08:10Z")
If you look at the topography of seattle, the port areas in particular, they should be the most worried.