Cascadia's Fault - Jerry Thompson [132]
To put this relatively small tsunami into context, the largest surge was only six feet high (1.8 m) from peak to trough. Not even as high as some of the regular storm tides in Crescent City harbor. The difference, according to Richard Young, was the speed—the manic rush—of the incoming waves. “The fact is that we have six-foot and eight-foot and ten-foot tidal changes here all the time with no damage,” he said. “The difference is that they [the tides] happen in six hours instead of ten minutes.” The damage estimate for this small, non-fatal tsunami was nearly $10 million.
On the positive side, NOAA’s ocean warning buoys and the new tsunami models, refined and upgraded by the Indian Ocean experience, had given scientists reason to believe they’d made a major breakthrough. Now when an undersea earthquake sets off seismic alarms, there will be information about wave generation as well. Emergency planners like Stephanie Fritts and Sheriff Benning won’t have to play guessing games with nature, wondering whether or not to issue evacuation orders to the citizens of Pacific County.
Vasily Titov extended the thought. “We cannot say when the next big earthquake is going to happen, but from the moment a tsunami is generated our models can actually tell you pretty well what happens next. How high the tsunami wave is going to be at the coastline, how big the impact is going to be at a particular location. The only thing we have to know for that is the actual measurement of the tsunami wave.”
The success of the tsunami models, even though they’re “never going to be perfect,” he said, “makes you feel that—gosh, all this mathematics that you learned in high school and the math at university can actually pay off and save lives. That’s a pretty amazing feeling Dry mathematics applied correctly—it can save lives.”
Chris Goldfinger, the marine geologist from Oregon State University, agreed with Titov. While still at sea off the coast of Sumatra, collecting mud-core samples in order to study how this earthquake happened, he couldn’t avoid thinking of home. With a mud core sliced open on his laboratory workbench and the sea gently heaving beneath the hull of the Roger Revelle, Goldfinger drew the connection.
“I have to admit mud is not very exciting to look at. It just looks like some sand and some mud. But now every time I look at these cores, I see that giant breaking wave ... It sort of brings home what these things really are,” he said. “Even though we work in the theory of all this, to actually see that for real was just stunning, and horrifying ... I think everyone’s pretty mindful of the reason we’re here,” he continued, with members of the Sumatra science team looking on, “and that maybe some of this research might help in some way.”
He paused for a moment and then tied the two stories together. “The same thing applies to Cascadia. I live there. And every time I drive to the coast, I see towns that are not long from now going to be under water from the next tsunami ... The Cascadia Subduction Zone earthquake and the tsunami that’ll come with it will be virtually identical to the one in 2004 in Sumatra. It’ll dwarf 1906 [in San Francisco]. And Katrina. It’ll be many dozens of Katrinas all at once. Coastal towns from northern California to Canada will be virtually wiped out. And there’ll be significant damage in all the coastal cities along there as well—all at the same time.”
Goldfinger agreed that knowing what Cascadia’s fault is capable of had utterly changed his perspective about living on the edge of a continent. “It’s a little hard to go to the beach and just hang out there and enjoy it.”
Garry Rogers at the Geological Survey of Canada told me that what happened in Sumatra should have come as no surprise—and yet it did. “To all the scientists it was obvious that that’s the kind of thing that happens,” Rogers said, matter-of-factly. “It was perhaps more severe in terms of death toll