Cascadia's Fault

by Jerry Thompson

  Each day after the loggers went home, Yamaguchi cut radial slices from the stumps they had left behind. Back at the lab, he drew diagrams with paper and pencil to confirm that they all shared a similar “bar code” of wide and narrow rings. Then he looked at the samples from the various ghost forests. “A number of them had more than two hundred rings in a series,” said Yamaguchi, “and it seemed like, at least theoretically, that would be enough for me to match against the living trees.” With a magnifying glass, a sharp pencil poised over his lab notebook, and an apparently infinite supply of patience, he began counting and cross-matching the rings of dead cedars against the baseline of cedars from the recent clearcut.

  “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 new science: “New geological findings being released today support a growing body of scientific evidence that Northern California and much of the Pacific Northwest may erupt in a giant earthquake, potentially endangering thousands of lives and hundreds of critical structures.” The specifics of what Carver and Burke had found were buried seven paragraphs below and on the next page: “According to Carver and Burke, evidence from the Little Salmon fault suggests that the Cascadia subduction zone comes on land at Cape Mendocino, and that earthquakes of 8.5 or greater have occurred on the fault, perhaps over very large areas.”

  It didn’t take long for the Bee story to hit the wire services. Before the morning’s coffee was cold, it had become a national news item. When Carver and Burke walked in to the convention hall in Phoenix they didn’t see the ton of bricks that was about to land on their heads. “I was met by GSA officials and hustled off for interviews with the national press,” Carver recalled. “I had no idea what was happening. Bud and I had said nothing about magnitude 9 earthquakes in our talks or abstracts and knew nothing of Israel’s article.”

  Carver was not amused. “The meeting officials put a beeper on me so they could track me down,” he said. Through the blur of the next several hours he did “a bunch of interviews” trying to explain the giant temblor story and trying even harder to dispel “the erroneous prediction” that Bill Israel had reported. “It was a trying day,” complained Carver. “When I got up to the podium that afternoon to give my talk, my beeper went off. The lecture room was standing room only and there were cameras and lights everywhere. I ignored the beep and got through the talk okay, but my nerves were shattered.”

  Was the prediction erroneous? Or simply unattributed? A closer reading of the Bee story shows that the magnitude 9 line had come from Heaton and Hartzell’s paper published back in April. The headline did not specify exactly who “feared” the giant shock, nor which of several groups of researchers mentioned in the story thought a 9.5 temblor was possible. Headlines seldom do. The new data from Carver and Burke were nowhere near as spectacular or unsettling as Heaton and Hartzell’s cautionary tale, so the Bee’s headline writer simply pulled zingers from the old story to sell a less dramatic new one.

  Israel had been hanging around the geology department at HSU long enough to collect the personal quotes he needed to show where Carver and Burke were coming from. “The potential power represented by the magnitude of such earthquakes, Carver said, is ‘awesome, incomprehensible,’” Israel wrote. He quoted Bud Burke as saying, “We’re living in a major earthquake zone . . . [The fault] is going to go in the next few generations—and it’s going to be big. I don’t think there’s any question about it.”

  Israel remembers it well. “I may have gotten them in a little trouble, but I don’t think they felt badly about what happened at all. In fact, I think it helped propel them,” he said. “Gary had done a lot of work in Alaska himself, after the great Alaska earthquake. It was clear at the time that what he was seeing in Alaska was related to what was going on here. So it was a very good time to be a geologist of the new faith. And these guys were all a part of that wave.”

  Looking back on it today, even Gary Carver sees some irony in the episode at Phoenix. “Interestingly, years later and based on the work of a number of researchers, evidence for great subduction earthquakes has become widely accepted,” he told me in an email. Despite the scary headline, Bill Israel’s story turned out to be accurate. Scientific opinion eventually caught up with Carver and Burke—even though they never really needed vindication. They had convinced Bill Israel that Cascadia’s fault was capable of monster quakes, and Israel did what he had to do as a journalist to relay that dismal news to the rest of the world.

  Once scientists had run through all the alternative explanations, eliminating the wrong answers and convinci
ng themselves the new geology was right, then like it or not the next job had to be getting the word out. After OSU’s Bob Yeats himself became “a convert,” he groaned about how difficult it was to get his wife, his neighbors, and state legislators in Oregon to take the coming quake seriously.

  “At first, it was the excitement of a scientific discovery” that kept Yeats motivated. Unfortunately, telling people about a catastrophic seismic threat was a lot like telling them that a lack of exercise and a bad diet and would make them fat. “The reaction was, ‘Yes, I know, but I don’t want to think about it, let alone do anything about it,’” Yeats wrote in his survival guide to earthquakes in the Pacific Northwest.

  After a while, though, public lethargy became a real drag. “Suddenly, earthquake science stopped being fun, and as a scientist, I began to feel like a watchman on the castle walls warning about barbarians at the gate, begging people to take me seriously,” he lamented. Despite recurring images in the news of death and destruction from previous subduction disasters, people seemingly didn’t have the will to respond. Perhaps burying one’s head in the sand is a type of survival mechanism, a way of coping.

  CHAPTER 13

  Cascadia’s Segmented Past: Apocalypse or Decades of Terror?

  For Stephanie Fritts, moving to a small town seemed like a logical way to escape the chaos and frenzy of the modern world. When she arrived in her chosen paradise on the western edge of Washington State, nobody said anything about megathrust earthquakes or tsunamis. Ilwaco was an idyllic resort community with a mild climate, white sandy shores, and tall green forests.

  She had lived the jet-set life of a fashion buyer for the May Company department store chain, and in the early days it seemed like a great job. Based in Portland, she spent half her life in New York hotels, missing her husband and children way too much. She began to question her “contribution to society” and decided that “clothing people just wasn’t doing it.”

  Then one day her father told her he could use some help running his department store—an old-fashioned local landmark that carried everything from ladies’ wear to oakum—in the fishing town of Ilwaco, just across the Oregon line in the lower left-hand corner of Washington State. Here the turbulent outflow of the Columbia River creates Cape Disappointment and the Long Beach Peninsula, a narrow, sandy spit that forms the outer boundary of Willapa Bay. A necklace of quiet little hideaways like Seaview, Long Beach, and Ocean Park were being transformed into retirement and tourist destinations famous for clam digs, sandcastles, kite festivals, and the scenic splendor of the Pacific.

  So Stephanie decided to make a lifestyle change. She went to work in her dad’s store and not long after settling in started volunteering as an emergency medical technician for the Pacific County ambulance service. She really liked the feel of public service, of doing something positive for society. She had no idea how much bigger that job would eventually become.

  Willapa Bay is the main place where Brian Atwater was quietly digging into tide marshes and stream banks in the spring and summer of 1986, finding evidence of huge prehistoric earthquakes and tsunamis. Few local residents were aware at the time that he was in the neighborhood or what he was up to, and it’s probably just as well because the news when it finally came out was most unwelcome. Like ships in the fog, he may even have crossed paths with Stephanie Fritts, unaware they would later join forces on a much-needed public safety campaign.

  Stephanie’s own introduction to plate tectonics and tsunami waves came on May 7 that year, when a distant rupture triggered a chain of events that would rattle nerves and change the lives of people living in Pacific County. On the Wednesday in question her husband, David, who worked in the lumber industry, had driven to Portland on business when a magnitude 8 quake sent shockwaves through the U.S. Naval Air Station on Adak Island, at the far end of the Aleutian archipelago 1,200 miles (1,900 km) southwest of Anchorage.

  It was the largest seismic event in Alaska since the Good Friday disaster of 1964. The ground shook and rolled for almost two minutes. Even though the event would be classified as a “great” earthquake (magnitude 8 or higher), it caused only moderate local damage—cracked masonry and concrete walls, collapsed ceilings and partition walls, spalling on concrete beams and piers—all of which was described by the Anchorage Daily News as “one of many temblors that rattle the chain every year.” Two things, however, made this one different.

  The first was that it had been forecast a year earlier by a team of scientists at the University of Colorado. The researchers were looking for precursors, things that change in the earth just before large main shocks. This being one of the most seismically active regions on the planet and the same big subduction zone that had caused the disaster of 1964, a whole slew of new instruments had been installed by 1974—the Central Aleutians Seismic Network—providing a flow of data with enough details to spot even subtle changes.

  One of those changes was a sudden drop-off of seismic activity. When all the normal rumble and grind along a big subduction zone mysteriously goes quiet, watch out—something’s bound to happen. Or at least that was the theory at the time. When this quiescence was noticed in a segment of the plate boundary near Adak Island, the researchers in Colorado decided to go out on a limb. They said a major earthquake would occur near Adak before the end of October 1985.

  When October came and went and the only big rupture was down in Mexico City, the scientists gracefully admitted their mistake and chalked it up to experience as a “failed prediction.” Six months later, on May 7, 1986, a quake roughly a hundred miles (160 km) southeast of Adak Island did occur at precisely the location they had thought it would. By then a new computer system had been installed at the Alaska Tsunami Warning Center in Palmer, just north of Anchorage. It was designed to record and locate the focal point of earthquakes quickly, analyze the data, and predict whether or not a tsunami had been generated at the same time.

  This was the second thing that made the May 7 shockwave different. It was the first test of the new software. The alarm system was tripped and a team of geophysicists on duty at Palmer had to decide whether to believe the computer. They knew this segment of the Pacific plate had failed before in a magnitude 8.6 temblor in 1957, generating a tsunami that did extensive damage in Hawaii. They confirmed very quickly that the current rupture was definitely located along the sea floor and was therefore certainly capable of generating waves. Whether it actually had or not was another question.

  Sometimes a slab of sea floor will move more horizontally than it does vertically, so these kinds of jolts don’t always lift a wall of water that becomes a tsunami. In the end it was a judgment call. With the odds apparently in favor, the team at Palmer did the cautious thing and notified emergency officials, who sounded the alarm all around the Pacific Rim that a wave had probably been triggered.

  From the moment of rupture until the alarm went out only eight minutes elapsed, less than half the time it used to take when the work was done by hand with calculators, rulers, and maps. The new system developed by Palmer station chief Thomas Sokolowski made this the fastest tsunami warning ever issued.

  The trouble was that the computer system was still based primarily on seismic data—instrument readings of the earthquake’s ground motion—with no quick way of directly measuring waves in the ocean. This was back in the days before deep-ocean detection buoys that could register a change in sea level and provide accurate data about how big the waves were and what to expect in places like Hawaii, Japan, Vancouver Island, or Willapa Bay—where a tsunami might be headed. Without the buoys, the new warning system was still an educated guess based on tide gauges and eyewitness reports from coastal communities when and if a wave made landfall.

  School was out and the kids had already made it home when the madness began. Up to her arms in soapy water, Stephanie Fritts stood in her driveway and stared at the spectacle for several minutes, not quite sure what was happening. By late afternoon that Wednesday the sun had come out and warm
ed the day enough to make washing the car a tolerable task, which is what Stephanie was doing when she noticed traffic—lots of it—heading southbound down the Long Beach Peninsula at high speed.

  She immediately switched on the radio and heard a cursory news story about a big wave possibly en route from Alaska and wasn’t sure what to do next. She tried phoning her husband in Portland. Again and again and again she tried, with no luck. The lines were jammed. She did eventually get through to her parents across town and told them she was on the way to pick them up. She wrangled four children—ages three to fifteen—into the car and decided not to worry for the moment about David because in Portland he should be far enough inland to be beyond the danger zone.

  But David was worried about her and the kids. After hearing the same vaguely ominous, fact-free news item on the car radio, he too made a dash for the nearest phone. He called the home number and called and called, unable to get through. So he decided to make a beeline for the family, driving west and north from Portland toward Astoria, where the big bridge crosses the Columbia just below Ilwaco. These were the days before most people had cell phones, so nobody in or near the danger zone could find out what was really happening. For David Fritts it was a shot in the dark.

  As the first wave, a 5.8-foot (1.8 m) swell, came ashore on Adak Island, emergency bulletins echoed down the west coast of North America from Alaska to British Columbia and on to Washington, Oregon, California, and Hawaii. The quake had indeed generated a tsunami. In Kodiak a siren started wailing shortly after 5:00 p.m. Alaska time to warn people that a wave could strike there within the hour. Over in Valdez, it was only the luck of the draw that no ships were docked at the Trans-Alaska Pipeline terminal. The captain of an inbound tanker decided to slow his vessel to twelve knots in order to stay in deep water until the danger passed.