A few years ago, I was sitting in the emergency operations center of a coastal California county that shall remain unidentified.
On the wall was a new (to me) map showing the areas that would be inundated by the tidal wave that might follow a large earthquake. I think it was based on a repeat of the 1964 Alaska quake, which produced a tsunami along the California coast.
One of the emergency managers noticed me looking at the map, and a conversation ensued about the value of the existing Pacific tsunami warning system. Of all of the potential disasters this guy faces, tsunamis are barely on his radar.
"Were talking about issuing a flash evacuation warning to a very local population and doing it perhaps once in a lifetime," the disaster planner lamented. "And then people have to take it seriously and do the right thing."
He didnt hold out tremendous hope, given the challenges involved. And this is in a prosperous country. Its hard to imagine a good Third World response.
There is, for example, the problem of the not-uncommon false alarms generated by the Pacific warning system. These were featured prominently in a television documentary I watched a few years ago.
Such warnings, resulting in only a minor change in the tide level, actually cause people to start going to the beach when a warning is issued. This has happened in Japan, and my friend believes it would happen in California as well. Then, when the "real" tsunami occurs, well ...
Maybe not today or tomorrow—while memories of the 2004 Indian Ocean tsunami remain fresh—but after a few years, memories fade and curiosity takes the place of fear. One of the dangers, according to my friend, is that people leaving high ground would actually block the escape of lowlanders trying to flee.
People also dont know what to do when confronted with tsunami conditions, as demonstrated by the current tragedy. The sudden, dramatic lowering of tide level that may precede a tsunami is as likely to send people scrambling to catch stranded fish as it is to send them running for their lives. There are reports that this is exactly what happened in some areas that later were inundated.
When a tsunami warning is issued, there is also the problem of getting the word out to people who might be affected. That is difficult in industrialized nations and almost impossible, I fear, everywhere else.
In the current case, it took only two hours for the tsunami to reach Sri Lanka and Indonesia, where most of the fatalities seem to have occurred. In these areas, you have large populations in low-lying areas, as well as poor communications. The disasters total death toll had risen to more than 134,000 people by Friday.
While many of those who died in Asia could have walked to safety given a two-hour warning, that would require them getting the message and actually believing it.
How do you tell millions of people living close to the sea that they need to leave—right now? Especially when many have never heard of a tsunami before.
Here in California, I can imagine a warning being issued but nobody in the media or public safety at the local level really knowing what to do with it. Valuable minutes might be wasted while considering the proper course of action. That was my friends concern.
Even if it were immediately disseminated via radio and television, there remains the problem of it being so novel that people wouldnt take it seriously. Even if they did, most communities would be hard-pressed to immediately tell residents how far inland to go, and serious traffic jams would doubtless ensue. So much for orderly evacuation.
Fortunately, tsunamis occur infrequently (PDF file), and damaging ones even less often. But thats the very quality that makes them hard to predict, hard to issue warnings for, and even harder for the warned population to know how to respond to. Even the best tsunami warning system will seem inadequate on a day like Dec. 26, 2004. But next time, residents of the Indian Ocean region may at least have a warning.