This study, regarding the effects of a 9.1 earthquake in Alaska, made the front page of the LA Times this morning:

http://www.weather.com/news/report-tsunami-would-swamp-californias-economy-20130905ijkk

The bad news - coastal areas like long Beach will be devastated. The good news - the area will have several hours warning.

I suppose this is one more factor in favor of South Dakota.

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Only real bad stuff to deal with here is tornadoes. Well, we get some wicked blizzards, too.

That was a Southern Cal perspective from the LA Times. For a Northern Cal perspective of the same report, you can read this article.

We would have about an hour less warning from an Alaska quake than Southern California. Much of the interior land areas of the San Francisco Bay are landfill, and not very high, so are quite vulnerable. The Port of Oakland (a major West coast port) and the Oakland Airport would both be knocked out for a while, it seems.

I recently saw a video from the Japan tsunami that I had not seen before. I will post a link to it after I go home and find the link again. It's another jaw dropping example of the deceptively sneaky way that a tsunami can start small and grow and grow to wreak total havoc.

A tsunami doesn't have to be this gigantic wave that breaks at the beach and crashes into shore. There's this image from the Indonesian tsunami that we've all seen many times where a tsunami smashes into a seawall and sends spray high into the air. But more often, it's like someone leaving the faucet in the bathtub running and the water level just keeps rising and rising until all your floating bath toys spill over the side and crash to the floor--and the water keeps on coming.

The effects of a tsunami depend considerably upon the shape of the terrain, both above and below sea level. Merely going inland isn't necessarily effective, especially if you are traveling up a river valley or other low lying area. You want to gain elevation.

My local county has modeled the extent of a ten foot tsunami and identified areas of risk, complete with cute little warning signs.

Correct. Often tsunamis act more like a very high tide that comes in very fast. Also keep in mind that tsunamis are often multiple waves that can come in over a period of many hours. And frequently the first one is not the hightest one. Much of the death and destruction in a tsunami is from debris carried in the fast moving water. Trees, houses, and other junk gets carried along by the water and acts like battering rams.

If a tsunami warning sounds, get to the highest ground you can, as fast as you can! If you cant get to high ground then find a very big, very sturdy building and go up several floors. Move fast!

And whatever you do, don't go down to the shore in order to watch the action, something that happens with surprising frequency....

I believe most coastal areas (at least on the west coast) have modeled or are in the process of modeling how high a tsunami could go.

For Washington State see Washinton Emergency Management's Tsunami page.

For Oregon, go to Oregon Tsunami Clearinghouse.

For California see California Tsunami Inundation Maps.

Alaska is still developing tsunami mapping. See the AEIC's Tsunami Mapping page. Fortunately for us in Anchorage, the configuration of upper Cook Inlet dissapates tsunamis before they get to Anchorage. In the 1964 quake there was no tsumami at Anchorage. However, Valdez, Seward, Kodiak, and Seldovia were hit hard with loss of life. Near the epicenter, the village of Chenega was obliterated with 23 (out of 75) villagers killed.

For lots of good general tsunami info see NOAA's TsunamiReady page.

After I posted my note upthread about tsunami info sites, I realized I had forgotton our friends in British Columbia. I'm less familiar with the Canadian geo-hazard info, but I found this link:

Emergency Management BC Tsunami Information

Great! Now being "underwater on your property" will no longer be just a figure of speech...

This is the video I mentioned in my previous post. It claims to be a "new" video of the Japanese tsunami and I had never seen it before, so I think it really is newly available.

It's rather long at 25 minutes, but it perfectly illustrates how deceptive a tsunami can be. I have no idea where this is but the ocean is nowhere to be seen. A low, calm river slowly but inexorably turns into a monstrous, churning destroyer of everything in its path.

DEAD LINK

Works for me. Scary stuff indeed!

I finally found time to watch the video. Very impressive! It illustrates the risk, even if you arn't right on the beach.

One further comment about evacuating due to a warning of a distant tsunami vs a tsunami generated by a nearby earthquake. In the case of a tsunami caused by a distant earthquake you might have several hours of warning. Time enough to grab your evacuation kit, hop in your car, and drive to high ground.

In the case of a tsunami resulting from a local earthquake, you might have only a very few minutes to escape. Roads are likely to be jammed by others trying to get away. The earthquake might have damaged or destroyed bridges or blocked roads. If you feel a strong earthquake it is probably better to escape on foot. Run like hell! Do not stop to grab your kit! Do not try to use your car. Get immediately to the highest ground available!

If there is no high ground nearby, there are other possibilities for safety. As the video shows, big, stoutly constructed buildings might survive and provide refuge. Even really big trees might work, though this would be an absolute last resort. High ground should always be your first choice.

In the video, it looks like fire came after water. A fire started halfway through the video (within 15 minutes of the arrival of the tsunami). Then a big neighborhood across from the river became swallowed up by flames. Fire often accompanies disasters, and in this case you might be left without anywhere to run to.

The people in the video also seemed incredibly calm. Or they just didn't verbalize their panic. "Well, it's a tsunami. Let's take some pictures while the whole neighborhood goes underwater or goes up in smoke." In the US, people would be screaming their heads off.

Japan is probably the most prepared nation on earth for earthquakes and tsunamis. From what I understand, they have a well organized emergency response system, and regularly do drills. You will have noticed the alert sirens and the guys in helmets directing people. I think the authorities in Japan have pre-designated and marked many buildings that are stout enough to serve as a refuge from tsunamis. We in the US have a long way to go to be as prepared as Japan.

If you understand what is happening, and have thought about and practiced your response, you are much more apt to remain calm in an emergency. One of my all time favorite quotes:

"People don’t rise to the occasion. They default to their training." -Attributed to Rick Rescorla, who was a former soldier who had become a coporate security officer. Due to his planning and training drills, all but six of the 2,700 Morgan Stanley employees survived the the attack on the World Trade Center on Sept. 11, 2001.

When something is so beyond your normal day-to-day experience, your brain tends to get overwhelmed. That's essentially what I think happens when people say some event felt so "surreal". That's exactly how I felt on 9/11 walking the streets of Manhattan. I was scared on the inside and also kind of disoriented, but I think I looked like a Zen monk on the outside.

Even with a video clip two years after the fact and basically knowing what to expect after having watched many other tsunami videos, my jaw still hung open the first time I watched the full clip and saw what the power of a tsunami could do.

Yes, that's the best advice. But the Japanese tsunami even inundated areas up in the coastal hills! There was so much force in the tsunami that it forced seawater to flow up rivers and streams to higher elevations. Imagine the shock of residents living in hills to find their fields flooded with saltwater!

Just following up in AKSAR's good advice, in the case of a locally generated tsunami and earthquake,you might be in the grips of the tsunami before you receive the warning, so, if in doubt, think seriously about doing a little climbing.

Historic precedent would be the Santa Barbra 1812 earthquake,whose epicenter was offshore in the Santa Barbara Channel. It generated a tsunami which reached the steps of the Santa Barbara Mission (not the current mission, but an earlier one at a lower elevation). A little while spent perusing your local tsunami hazard map can be time well spent.

Tsunamis can also look like a flash flood. Or for inlanders, a flash flood can resemble a tsunami.

I have a weekend cabin in Central Texas about 200 miles inland. I have a picture from 1992 - before I owned the property - of someone paddling a canoe through the lower field during flooding after heavy rains.

What makes that picture instructive is that a survey when I bought the place shows that the lower field is sixty (60) feet above the river.

You don't need to be on the coast to have a serious water-rise event to deal with.

"a flash flood can resemble a tsunami". The classic southwestern flash floods do very good tsunami impressions.

One minute you have a dry arroyo. There is a rumbling sound and a wall of water descends the drainage - quite literally dry one second, and flood water the next. The tallest wave I have witnessed was about five feet high.

Hikermor and James_Van_Artsdale make a good point. San Antonio, Texas and Lima, Peru both occupy arid or desert locations. Dry enough that many areas in both cities have minimal or non-existant storm drainage. Yet, both cities have registered drowning deaths due to flash-flooding in the last 15 years. One woman was a close friend of my sister.

During the time I was doing SAR around Tucson, AZ, drowning was a leading cause of fatalities, far ahead of hyperthermia, and close to falling. Typically people drove around barricades closing off flooded roads. The high wave front I witnessed roared downstream through a narrow canyon filled with people, killing seven almost instantly. It took us a week to find them all.