By February of 1979 Karen McNally was back in her Pasadena office, seismograms happily draped over a desk which in turn held various strata of books, papers, notes, information, lesson plans, and copies of professional journals. There would be years of study of the reams of information from Mexico, and many more field trips to the Mexican coast to work on other seismic gap areas. But things did seem, in a somewhat disjointed way, to be falling together.
There was an excitement in the air among the seismologists, geologists, geophysicists, and even volcanologists—an excitement which went beyond the natural exhilaration of advancing the science. In part it was a continuation of the rush of enthusiasm that followed the acceptance of the plate tectonic model, and in part it was a result of additional funding and support through the 1977 Earthquake Hazard Reduction Act. For those like McNally, whose insatiable curiosity was channeled by the happy and heretical faith that each individual researcher could make a difference, the renewed chance to keep looking for the answers and clues—the hope of finding ways of predicting earthquakes—meant a limitless horizon.
But another aspect of that excitement was the general impression that having been handed the prodigious task of finding methods and constructing the systems within ten years for effective earthquake forecasting (one of the stated goals of the hazard reduction act), the geophysical community was actually meeting the challenge.
For one thing, the definition of what really constituted an earthquake prediction had already begun to change. The Chinese were responsible for starting that alteration, recognizing on reexamination that while predicting a great quake within hours could obviously save hundreds of thousands of lives, there was equal value in knowing where a great quake (or even a lesser quake) would strike sometime in the future, or in knowing that (as with seismic gaps) a quake was due within months to a few years. There were different things that a society could do when faced with different levels of predictions. Obviously a short-term warning that a major seismic calamity was due within a few hours to a few weeks would not provide sufficient time for reconstructing buildings or dams, enacting new standards of land use planning, or encouraging resettlement away from high-risk areas. A long-term prediction, however, would permit just such activity, and if the recommendations were carried out faithfully as the years passed, the value of such a prediction and the hazard-reducing actions it sparked could save thousands of lives and untold billions of dollars of property.
By the same token, an intermediate-term prediction within a few weeks to a few years would provide valuable time for rechecking existing structures and preparing emergency response agencies and functions for the inevitable.
When a particular area is identified as subject to a damaging earthquake, that fact alone is a prediction, and each stage of refinement in terms of probable time of occurrence can be of immense value to a nation. Therefore, a failure to predict precisely time, magnitude, and location within days or hours, may not be a failure at all. But that attitude had not yet been accepted in America.
The startling element, as Karen McNally would write in a professional paper a few years later, was the fact that “The locations of most large earthquakes likely to occur in the future are rather well known based on the seismic gap method, which integrates the history of previous large earthquakes, the rates of plate motion, and geologic slip rates. Similarly, the size of a future large earthquake can be estimated from the dimensions of a seismic gap.”6
In other words, within a few years of the passage of the hazard reduction act, long-term prediction was already within the realm of possibility, and in some cases, effectively operational (for major quakes).7
As a result of the work of scientists like Karen McNally and Kerry Sieh, and so many others, intermediate-term forecasts were also showing great promise.8 In the same paper (“Variations in Seismicity as a Fundamental Tool in Earthquake Prediction,” published a few years later), Karen McNally characterized the progress by pointing out that: “The current stage of research is comparable to that existing prior to the understanding of plate tectonic theory. A number of systematic patterns are observed which are suggestive of underlying processes, other patterns appear random, and no unifying model has yet been found with which earthquakes can be predicted.”
But as she and her colleagues knew, there would need to be a substantial revision in the understanding of just what it was that seismology was supposed to accomplish within the ten-year period foreseen by the 1977 hazard reduction act. There was growing pessimism that the problem was far more difficult than originally thought, and that pessimism was beginning to retard progress—and recognition of what had already been accomplished.
“Being perfect scientists,” she explained, “we want the perfect solution. When we can’t find it as readily as we want, we get frustrated, and get to thinking that perhaps we can’t find a perfect solution, so the entire thrust of the research project is a failure.”
The Russian-discovered, American-refined dilatancy theory was a prime example. The 1977 bill washed in on a wave of optimism created in part by dilatancy—but by 1979 the bright hope that P wave slowdown and speedup could provide a unified key had been dashed by the reality that some earthquakes exhibited no changes in wave speed, and in others the behavior patterns were not predictable. Instead of scientists’ using what aspects of dilatancy might be helpful in looking for a multifaceted array of indicators that a quake was coming and when it would occur, dilatancy as a theory had been largely discredited and in too many cases discarded. There was still some value to it, though. P waves did, in fact, slow down and speed up in certain cases, and some successful predictions had been made solely on the basis of the phenomenon.
Nevertheless, by early 1979 there had been at least one stunningly successful intermediate-term prediction that had nothing to do with dilatancy—the Oaxaca quake. What’s more, by January 1979 another intermediate-term forecast had been made with a degree of courage which gave real hope to the scientific community that perhaps—despite the highly restrictive definition of what a prediction was supposed to be—real progress was being made.
Specifically a pattern of small tremors (anomalous seismicity, they were called) had occurred six months prior to a pair of large earthquakes (magnitude Ms 7.1 and 6.9) in the High Sierras of California in 1954. The seismic murmurings had begun after a lengthy period of seismic quiescence, and the record of the ensuing flurry of activity had been preserved on older seismograph tracings.
Suddenly, in late 1978, after another period of quiet, the same pattern began again. Several seismologists who had paid close attention to Karen McNally’s success in Oaxaca concluded that what they had was a pattern preceding an earthquake, and taking a deep breath, they forecast what they thought was coming: a large quake in the vicinity of the beautiful resort community of Mammoth Lakes, California, nestled in the High Sierras to the east of Yosemite, at the north end of the Owens Valley, and in a fascinating formation ringed by ridgelike volcanic cliffs known as Long Valley.
The prediction, it seemed, was only the beginning.
Chapter 18
Vancouver, Washington—Thursday, May 22, 1980
As Rob Wesson looked up, the President of the United States came through the door.
Sweeping in suddenly past two typically dour Secret Service men and accompanied by Dr. Frank Press, his science advisor, Jimmy Carter looked around the crowded second-story office as a half dozen USGS scientists looked back in stunned silence.
They knew the President was due to visit the ground-floor level of the U.S. Forest Service headquarters in Vancouver, but they had intended to stay out of the way. Now, without warning, he was in their midst.
The smoking hulk that had been the beautiful snowcapped Mount St. Helens had drawn the constant attention of the survey’s volcanologists for the previous two months, as a growing cadre of scientists edged ever closer to an open prediction of the cataclysmic explosion that, in fact, occurred on Sunday morning, May 18, at 8:
27 A.M. Now, four days later, deeply shocked by the volcanic eruption which had killed sixty-one people (including USGS volcanologist Dr. David Johnston), spread ash over a quarter of the nation, halted the economy of Washington State for several days, and grabbed the attention of the world, the President had come to see for himself. U.S. Forest Service headquarters in Vancouver—the building being used as a temporary headquarters by the USGS “mission”—was the first stop. Carter would fly around the mountain by helicopter later in the day.
“Hello, Frank.” Dr. Robert Wesson, still stunned, extended his hand to the familiar form of Frank Press, who was standing slightly in front of President Carter. It seemed the appropriate thing to do. No one else had moved.
The President was searching for something to say, and someone to say it to, amidst a rather awkward situation. The roomful of scientists were still frozen in awed silence, all staring at the commander in chief and waiting for someone to break the ice.
“Rob! How are you?” Dr. Press responded.
Carter turned toward Wesson and Press.
“You two know each other?” The familiar Georgian accent broke the silence as Dr. Press began introductions, starting with Wesson, who had been sent out hours after the explosion as the personal representative of the USGS director, Bill Menard.
“Certainly. Mr. President, meet Dr. Robert Wesson of the USGS.”
Rob Wesson had not wanted to come to Vancouver, but the relationship between the USGS director and the field detachment monitoring the explosive situation at St. Helens had been choked by poor communication through the intermediate bureaucratic layers, and Menard wanted a personal representative on the scene. Wesson tried, unsuccessfully, to talk him out of it, then caught a red-eye flight on Sunday to Portland, Oregon, arriving at the USGS outpost in Vancouver in time to watch the awful expression on the face of the USGS team leader as he got the news of Dr. David Johnston’s last radioed words:
“Vancouver … Vancouver, this is it!”
“This mountain is a powder keg, and the fuse is lit,” Johnston had told the press a month earlier, “… but we don’t know how long the fuse is.” The thirty-year-old Ph.D. in geology from the University of Washington had made several helicopter-borne dashes into the new crater of the reawakening volcano after it cleared its throat with ash plume eruptions in late March. On Sunday morning, May 18, 1980, Johnston awoke from his first night on the ridge south of Coldwater Creek, dubbed Coldwater II, and began checking the array of monitoring instruments trained on the deadly mountain, which stood a mere six miles away. At dawn he had radioed that all was quiet and beautiful, the sun just breaking over the verdant forest to the east, a wisp of steam and ash curling from the conical top of the peak.
Suddenly, at 8:27 A.M., an earthquake of 5.0 magnitude shook the mountain, the epicenter from somewhere beneath, the seismic waves radiating upward to shake the north face of the volcano, which had been bulging—swelling—at the rate of five feet per day during the last few weeks, a bulge now some three hundred feet displaced from normal. With the episodic earthquakes that had rocked the area before the first ash plume of March (announcing the movement of magma beneath and the reactivation of the volatile mountain) and the more recent harmonic tremors, indicating larger amounts of liquid rock flowing somewhere below, the precursors of a possible major eruption were obvious. Johnston and many others fully expected the mountain to erupt in a major, vertical explosion so typical of subduction zone volcanoes with magma rich in silica.1
It was these worries that had prompted Washington Governor Dixy Lee Ray—herself an accomplished scientist and former head of the Nuclear Regulatory Commission—to establish a “red zone” around the mountain, giving state officials and county officials monstrous headaches in controlling the entries and exits of citizens and residents who couldn’t believe the threat was real.
At 8:27 A.M. David Johnston felt the tremors. He watched the mountain for the next few minutes, the possibility of further quakes or some activity triggered by the quake now very high. No volcanologist at that point would have been surprised to see a monstrous plume of ash and steam and pyroclastic material (molten and partially cooled rock in a mixture of searing, glowing gases) shoot straight up from the peak, perhaps taking much of the top cone with it.
Instead, at 8:32:37, five minutes after the seismic waves had unhinged the critical structure of the north face—the lid of the pressure cooker—a landslide began on the north flank, a debris flow descending down in a mammoth movement of material at the very spot that Johnston and others had documented the worrisome bulge, and at the very point where an ancient magma flow had formed a massive plug, bottling up the incredible forces of the volcanic bomb which had pressurized behind the wall of rock on St. Helens’ flank.
In mere seconds the falling curtain of rock was replaced by the plume of ash and steam which came shooting out laterally, to the north, toward Johnston’s position, followed by a vertical plume and then a lateral blast. In the seconds after the blast had started, Johnston grabbed the microphone of his VHF radio with excitement tinging his voice, beginning the unfinished message to Vancouver: “… this is it!”
Fourteen seconds after the start of the landslide, a cataclysmic surge of pyroclastic material carried on a deadly two-hundred-mileper-hour wave of superheated gases shot out to the north, taking approximately one minute and forty-nine seconds to reach Coldwater II, blowing the young geologist off the ridge as it seared him and his equipment with unsurvivable temperatures cloaked in a fog of unbreathable ash.
President Carter was shocked by the destruction he saw below as the presidential party flew back and forth around the smoking remnants of what had been the crown jewel in the stunning array of the Cascadia volcanoes. It looked like a moonscape, he remarked, as several officials, including Governor Ray, pointed out various areas and discussed the differing problems and needs. Without question this segment of Washington was a disaster area, and without question federal assistance would be needed in significant amounts. Most of the budget of the state for emergency services had already been exhausted.
The governor had been faced with an agonizing two months of controversy. Would St. Helens blow up or not? That was the central question. How much responsibility should the state take to prevent people from putting themselves in harm’s way? Where was the dividing line between our hallowed freedoms to determine our own individual levels of acceptable risk, and the state’s responsibility for preserving life and property? As property owners in the region griped and worried, resisting evacuation efforts while listening attentively to the opinions of the uneasy scientists and government leaders, the agony of predicting a major and deadly geologic event became all too clear.
The USGS team members kept monitoring Mount St. Helens with the increasing belief that an explosion was coming, but with a corresponding reluctance to make that a blanket prediction. Though they were besieged for conclusions and opinions, it was all too obvious that the social and economic consequences of making the wrong call could be severe, and no one really knew what the mountain was going to do. Volcanology was shrouded in more mystery and uncertainty than was seismology.
As the first week of May passed, it was puzzling to realize that even with a smoking hole in the top of the mountain spouting ash, and a cadre of scientists monitoring earth tremors and saying worried, cautious things, there were still scores of people in the area refusing to believe that the mountain was dangerous. The Mount St. Helens they knew—the Spirit Lake they loved—had never been blown away before in their lifetimes. Why should they expect such a result now? Even with eruptions as recent as mid-April 1857 to validate its status as an active and dangerous volcano, Washington state and county officials faced a constant battle enforcing the evacuation of the red zone around the mountain.
One of those battles had been lost from the first, as Spirit Lake resident Harry Truman (no relation to the former president) refused to leave the mountain and his commercial lodge no matter how ser
ious the threat. Truman’s constant interviews on radio and TV in the weeks before the explosion (at the behest of a fascinated media) made him an overnight celebrity, but on May 18 he paid the ultimate price: He and his lodge were swept away and buried by the first wave of firey, pyroclastic materials down the north slope.
And with the explosion of May 18th came the typical finger pointing and recriminations over those who were in the zone, and who did not come out. People such as Dr. David Johnston were there for a valid purpose—many more were not. Despite the hundreds (if not thousands) of lives saved by the forthright actions of the state, the dark worry of what would have become of the evacuation effort if it had been Mount Rainier and the populated regions of Pierce County (which contains the city of Tacoma, among others) that had been threatened weighed heavily on the minds of the officials involved. There were serious lessons there. In fact, St. Helens, as bad as it was, was merely a warning. Someday, undoubtedly, Mount Rainier could reawaken as well.
Air Force One had reached cruising altitude as President Carter and Dr. Frank Press talked about the amazing things they had seen.
“I just can’t believe the destruction down there,” the President remarked at one point.
Dr. Press, long an advocate of hazard mitigation for geologic threats, especially those of earthquakes, and knowledgeable of the latest research, including Dr. Kerry Sieh’s breakthrough findings on the southern San Andreas, looked Jimmy Carter in the eye.
“That, Mr. President, is nothing compared to the scope of the disaster we’re going to have in Los Angeles when the great quake that’s coming finally occurs.”
The President was astounded. As Press filled him in on the scope of the human loss which would inevitably occur, the deaths and injuries, the loss of property in the tens of billions, and the danger to American defense installations up and down the southern coastline, Carter made the decision to form an immediate ad hoc committee within the National Security Council to look into the matter and what the country needed to do to prepare.
On Shaky Ground Page 26