Monday, March 14, 2011

Deep History: earthquakes and human history

It's hard not to reflect on how ill-prepared our societies are for events like the Japanese earthquake and tsunami.  Japan is probably the best prepared nation in the world, with most of its building earthquake-resistant, with berms and seawalls along a large part of its exposed coastlines, and with extensive emergency training for its citizens.  Presumably that means things could have been worse there in the past few days.

But for all the preparation Japan has done, the damage there is catastrophic and heartrending, and the defences seem hopelessly inadequate.  We cannot help but wonder: How well prepared, by comparison, is the west coast of North America?

Strange thing is, we are the first society ever to have the option of considering how to prepare for high-magnitude earthquakes and tsunamis. At any particular location on the Ring of Fire, they may come along every three- to eight hundred years. What human society until ours has ever even been able to consider planning for events that may occur every 500 years?

It's only our history-drenched (and scientifically-informed) societies that can maintain, however dimly, a five hundred year event horizon. We actually can calculate rather precisely what will happen when the next Big One occurs on the Canadian-American west coast.

Indeed, There is amazingly precise information available about the history of the magnitude 9 earthquake and tsunami that devastated the west coast of British Columbia and the Pacific Northwest on January 26, 1700 and did considerable damage even on the coast of Japan  (See the information summary and links here.)  But even the West Coast aboriginal survivors of that disaster probably moved back to the coast as soon as they could, if only because they depended so completely on marine resources. Word of the event would not have travelled very far, and even where it was preserved in oral tradition or written records, there could have been few practical ways to avoid or mitigate damage from the next one.

How much we, with our historical information and foreknowledge, can act to mitigate our next one... that's the question.
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