Cascadia's Fault - Jerry Thompson [70]
“When we started coming up with dates,” he recalled, “a few of the trees had rings up until the early 1690s.” The most precise date he could be sure of was 1691, meaning the trees had lived at least until then—maybe longer. It was impossible to nail the precise year of death because even the durable old cedars had taken a beating after three centuries of harsh coastal storms, bugs, fire, and rot. The outer bark and final ring of growth were simply not there any more. “The earthquake had happened sometime shortly after 1691,” Yamaguchi figured, “but I didn’t know how many years afterward.”
Atwater and others at the University of Washington managed to narrow the timeline a bit more. He returned to the old quake-killed spruce stumps on the Copalis River and at Willapa Bay, where he chainsawed some samples that—unlike the cedar—still had intact bark. At the university, a team of radiocarbon analysts then used the spruce slices to limit the time of death to some time between 1680 and 1720—with a high degree of accuracy. Not an exact date, but at least it was progress.
In October 1987 Gary Carver, Bud Burke, and several of the graduate students at Humboldt State University were putting the final touches on a paper they intended to release in Phoenix at the annual meeting of the Geological Society of America. Their research on the tectonics of northwest California was finally ready for publication. Nothing splashy was planned, just another incremental step along the road to resolution of the Cascadia Subduction Zone mystery.
Bill Israel, a local journalist in Eureka, however, had been paying close attention to the news of this emerging Humboldt County seismic threat and recognized the implications of what the HSU team had found. He knew about Carver and Burke, he had read Heaton and Hartzell’s comparison of Cascadia to Chile and Alaska, and he was aware of Brian Atwater’s sunken coastline data. In the weeks leading up to the big convention in Phoenix, Israel had been hanging around the geology department at Humboldt State while the Carver and Burke paper was being polished.
Ever since the Ferndale earthquake in June 1975, when cracks had appeared in the concrete roadway leading up to the nuclear power station, Israel had kept tabs on the seismic risk analysis that PG&E was conducting. He knew about the Little Salmon fault and had learned of Gary Carver’s growing list of other active fractures. When Tom Collins of the U.S. Forest Service recognized the distinctive rhombohedral fracture pattern in the sandpit across the road from the reactor and filed a report with the Nuclear Regulatory Commission, Bill Israel knew he was on to an important story.
He was also aware that Carver and Burke could not release their results to the media until the paper had been peer reviewed and published or presented formally at a gathering like the GSA meeting in Phoenix. So Israel collected bits and pieces of information, dug up background material about Heaton and Hartzell, Atwater, and others, then bided his time, tacitly agreeing to embargo his story until the morning of the big convention when it would all become official.
“Somehow he got the idea we were predicting a giant magnitude 9 earthquake for Cascadia,” Carver told me. If you read the fine print of the document that was released in Phoenix that morning, neither Carver nor Burke said anything about a monster shockwave. But on Wednesday, October 28, 1987, the Sacramento Bee carried Bill Israel’s story under a headline that proclaimed, “Giant Northwest quake feared.” The subhead made it even more ominous: “Researchers say 9.5 temblor possible.”
The opening sentence told a story of paradigm shift, another confirmation of the heretical