Pete & Doug,

I think you may be misunderstanding the purpose of this scenario. Risks associated with earthquakes might be broken into several broad categories.

First there is the immediate local damage and distruction associated with the earthquake itself. In North America, think of San Francisco in 1906, Anchorage in 1964, or Northridge in 1994. These can occur and cause damage anywhere, not just along the coast. The most severe damage is generally within a couple of hundred kilometers of the actual earthquake. In areas with a history of such earthquakes, the hazard is generally well known and understood by both the population and emergency planners.

In coastal areas, a local earthquake can also create a tsunami and cause severe damage along the nearby coast. Warning time is very short, perhaps only 15-25 minutes, and tsunami damage will be added to that initially caused by the earthquake. Historical examples in N America would be Seward, Kodiak, Valdez, Old Chenaga, and other Alaskan communities after the 1964 quake. Coastal communities in Oregon, Washington, and British Columbia are at great risk of a tsunami after a major quake along the Cascadia Subduction Zone. That risk has not been well understood in the past, but is beginning to be widely publicized by the USGS and other agencies.

The third type of hazard is a tsunami from a distant earthquake hitting the West Coast of North America. This would be a situation where there is no local earthquake to get peoples attention, but there might be as much as 4 hours of warning of the approach of the tsunami. This is a very different sort of problem. While a few local areas on the west coast (eg. Crescent City, CA) have suffered from these kinds of events, the hazard is not as well recognized as it should be by many emergency planners and most of the population as a whole. That is the problem this scenario is meant to emphasize.

While this publication focuses on the effects on Los Angeles (which is after all the largest population center on the West Coast), I think it is really meant as a template for any area on the coast. Also, the report dicusses the wide spread economic effects of damage to the ports of Los Angeles and Long Beach. The economic impact would extend far beyond coastal California! (Other major west coast ports such as Seattle and San Francisco are not as likely to be damaged by a tsunami from a far distant earthquake.)

For example, last night I was browsing through Chapter J, "Emergency Management Response to a Warning-Level Alaska-Source Tsunami Impacting California". It is an interesting look at the problems emergency management officials would face if given 4 hours warning of an approaching tsunami. How do you get the word out? How do you best use that warning time to mitigate the effects on the port? Distant tsunamis can consist of several waves, over a period of hours, and the first wave is not always the largest. How do you keep people from returning to the coast after the first wave has come and gone?
Not simple problems.