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Tuesday, March 02, 2010

Why Hawaii Won't Ever Get a Huge Tsunami: a contrarian view (with farewell video of evacuation orders via loudspeaker)

Here's the way it was on Saturday morning at 5 a.m. back in those innocent days when we still believed in Papa Tsunami. The very able fire dept truck goes by, broadcasting the evacuation. These are top-notch professionals. (Hawaii firefighters are unique in that they take part in a lot of water rescues, probably more than fire calls.) Next we see a pickup truck loaded with coolers of food and water and a longboard, driven by a local gal. Neighbors on the curb are beginning to draw up plans.

And now, here's something the Tsunami Center won't tell you, as a parting thought: the Hawaiian islands are the most isolated chain in the world, and as such are at a very far remove from the major earthquake fault subduction zones in the Pacific Rim. If you think of the Rim as a circle, Hawaii is in the center. Though there is an active volcanic earthquake scene on the Big Island, these kinds of earthquakes are shallow and unlikely to affect even the neighbor islands in any significant way. I'm from California, where earthquakes are a real threat. My grandfather wrote most of the first earthquake-resistant building code after the 1933 Long Beach quake. He consulted in Chile's reconstruction after the 1960 quake. We grew up talking, and reading about, and comparing experiences with earthquakes in our house.

And my point is this: Hawaii is too far away to ever receive a full on 20+ foot Indonesian-style tsunami except (note emphasis) in those fjords and harbors which funnel the wave force, such as at Hilo, which is the only major population area to suffer a serious loss of life and damage. While there will be tsunamis in the years to come, they will be in the 1 to 4 foot range unless an earthquake even stronger than the largest ever recorded--Chile 1960--strikes opposite those fjords and harbors. At 1 to 4 feet, there may be street flooding and beach erosion and major inconveniences and some loss of life--some dumb surfer is going to get it, one of these days--but nothing compared to what the East Coast goes through 3 or 4 times a year with Nor'easters.

This is the sort of prediction that can outrage people. It can weigh like an albatross if proved wrong, but I'm willing to make it in order to emphasize the kind of provincial and panic-based thinking that goes on, still, in the places that are funded to protect us. They need to keep that funding going, so the danger has to manifest frequently enough to keep the budget line alive.

The places where tsunamis do horrible damage are those closest to the Pacific Rim subduction and strike-fault zones. Japan. Indonesia. Chile. Alaska. The Pacific Northwest. California. They're at the outer circumference of the Rim, not at the center, as we are.

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