Saturday, September 19, 2015

another piece on the Cascade subduction zone, this article shifts some emphasis to reliance on folklore as actual history

Two observations on this for the weekend before you read the excerpt:

1) even in science intuition and hunches have a role.  The ideological insistence that all science is only ever guided by "the scientific method" forgets that there are a lot of methods for testing a hypothesis for the confirmation or rejection of the applicability of a hypothesis.

2) consulting folklore from American Indian tribes along the Pacific Northwest coast played a crucial role in the formulation of the idea of the Cascade subduction zone.  If all the white settlers and 19th century thinkers who believed the forward progress of the American manifest destiny who wanted to kill off all the Indians had gotten their way there'd have been no folkloric legacy from which the scientists could have formulated their theory.
Then in the early 1980s, the U.S. Nuclear Regulatory Commission was considering whether to locate nuclear power plants in Washington and Oregon, and just to be sure, asked the U.S. Geological Survey whether the Cascadia subduction zone was safe from earthquakes. Heaton, then at the USGS, knew about subduction zones because he’d consulted for Exxon on oil platforms in earthquake-prone Alaska. He compared the Cascadia zone with known earthquake areas and told the NRC, “Well, maybe it is aseismic, but another interpretation is, it looks like Chile—which is also aseismic, except for the big ones.” Perhaps, Heaton suggested, the Cascadia zone had escaped earthquakes only because it was currently locked.

Heaton published his surmise in 1984, and within a few years, Brian Atwater, also at the USGS, and other geologists found evidence of moving ground and great floods. But building geological evidence into a credible theory can take decades, and in the meantime, a colleague of Atwater and Heaton’s named Parke Snavely had been reading stories from the Makah people in Washington that described what sounded like floods. One Makah story in particular resembled the 1700 tsunami. “A long time ago but not at a very remote period,” the story began, the ocean receded quickly, then rose again until it submerged Cape Flattery; canoes were stranded in trees and many people died.

Snavely told Heaton about the stories, and the two of them did something un-geoscientific: They decided to take the Makah story not as myth, but as history. That is, they assumed the Makah were describing a geologically recent tsunami, compared the Makah narrative with their understanding of Cape Flattery’s geology, found the similarity between story and geology “noteworthy,” and published their findings in the scientific literature. After that, other scientists also went looking in the stories for history. A team of anthropologists, geologists, and indigenous scholars led by geologist Ruth Ludwin of the University of Washington took 40 stories collected from native groups along the entire Cascadia subduction zone. They compared the narratives to what was known of the 1700 earthquake and tsunami and found in effect that the whole coast had been telling stories about it.


Many scientific papers say that the indigenous stories are reasonable records, covering an unknowable amount of time, of earthquakes and tsunamis along the entire Cascadia subduction zone. They also add that so much destruction repeated for so long must have had a terrific impact on the indigenous groups’ worlds—that given their history, the indigenous people of the Pacific Northwest would have taken catastrophe to heart. You might expect that they’d arranged their culture and lives around disaster. And further, you might hope that the impact on them would have some message, some advice, for us in the 21st century, waiting for our own disaster. But here’s where this storyline goes cold. Any such impact ought to show up in archaeological and anthropological evidence, and it just doesn’t.
The people must have lost their houses and villages and livelihoods—they must have been ruined; but afterward they went back to living in the ruined places. McMillan went looking in the archaeological record for evidence of habitation and abandonment over the past 3,000 years in 30 excavated villages along the Washington and Vancouver Island coasts. “The seismic events were catastrophic but short term,” McMillan says. “The evidence is all that the sites were reoccupied afterward.”

These last two quoted paragraphs seem to reflect an assumption that the local tribes had cities and civilizations of the sort that foster stuff like Seattle, which doesn't even allow for its own public transit and foists that on to King County infrastructure. :) How hard is it to re-occupy where you used to live if you live in tents compared to if you live in multi-story condos?

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