Saturday’s powerful earthquake off Chile is the same type of tremor that scientists are warning will hit Oregon eventually. But scientists say there’s a lot still to be learned about the tsunamis caused by far-away earthquakes.
And as Rob Manning reports, that makes policy-making hard.
Vicki McConnell is Oregon’s state geologist. Saturday, she was tracking the tsunami, as it progressed from Chile, toward Oregon.
Vicki McConnell: “We knew that we would have some effect at the coast. We also knew from the initial modeling – which is wonderful that we have that capability that it would not be anything that would be life-threatening.”
But where the tsunami models were exciting for McConnell, their limitations are troubling to scientists and policy makers.
Harry Yeh is an engineering professor at Oregon State University. He says the models accurately predicted when Saturday’s tsunami would arrive across the Pacific. But they failed on predicting size. In Japan, the prediction was for three-meter waves. They were half that size.
Harry Yeh: “That’s a big difference, isn’t it? I mean three meters gives you big damage. But one-point-five meters gives you flooding, but it’s not that damage.”
Yeh says the models also aren’t good at predicting how swift the currents are – and he says fast waves can be at least as dangerous as big ones.
Yeh’s colleague at OSU, geologist, Chris Goldfinger is studying tsunamis from both ends – the Oregon sea floor where tsunamis land, and where they start, with the quake. He says progress has been made on tracking waves and on-shore impacts.
Chris Goldfinger: “What we haven’t done so well with, I don’t think, is the actual source earthquake.”
Tsunamis don’t happen often, so research is slow. The information gap leaves public officials with a dilemma: do they issue warnings, when nothing might happen?
OSU engineering professor, Harry Yeh advocates issuing the warnings, because the next time, scientists might underestimate the risks, and officials could risk people’s lives by not warning them. But Chris Goldfinger says the warnings carry a risk, too.
Chris Goldfinger: “The first few times out, we’ve had essentially some false alarms, and there’s a concern that if you do too much of that, people will stop listening to the message.”
Yeh counters that Saturday’s tsunami was not a false alarm. It just had a greater impact in places like Japan, than in Oregon and Washington.