The West Coast and Alaska Tsunami Warning Center provides tsunami warnings for both the east and west coasts of the US and Canada. The Pacific Tsunami Warning Center in Hawaii provides coverage for Hawaii and much of the rest of the Pacific Rim. The Alaska facility is located in Palmer, about 40 miles (64 km) north of Anchorage. I've toured it several times. If by chance any of you are ever in the area, it is well worth a visit. The do a very nice public tour.

Staff are on duty 24/7/365 monitoring a large network of seismographs, tsunami detection buoys, and tide gauges. Typically, the first indication of a potential tsunami is when a large undersea earthquake is detected. They have equipment to rapidly give a preliminary analysis of size, location, and focal mechanism of major earthquakes virtually anwhere in the world. Based on this, the staff makes a rapid estimate of the potential for a dangerous tsunami, and may issue various levels of "Warning", "Watch", etc. One of the staff told me that when the recent Japanese earthquake and tsunami occured, they were on the phone with government emergency agencies before the ground had stopped shaking in Japan. As the tsunami crosses the ocean, tsunami buoys and tide gauges enable the staff to modify or cancel warnings as appropriate. For some more details see their Users Guide.

Of course Alaska itself is prone to large devastating earthquakes. One of the questions I asked is the likelihood that the Alaska Center itself could be knocked out by an earthquake. They said that the center is stoutly constructed to resist earthquakes, and has its own back up power. In the worst case, they have a portable sat phone handy, and could call the Hawaii center to have them take over. Since both centers are tied into the same data network, either one is capable of covering the area of the other, and could issue warnings.

All in all a very interesting place to tour. It is well worth a stop if you are ever visiting Alaska.