The Great Quake: How the Biggest Earthquake in North America Changed Our Understanding of the Planet

by Henry Fountain

George Plafker at a spike camp in Alaska in the 1960s. Courtesy of George Plafker

  The Don J. Miller, the barge that George Plafker and others used for their work in the summer of 1964. US Geological Survey

  One of George Plafker’s assistants holding a rod next to barnacles to measure elevation changes from the earthquake. US Geological Survey

  The damage on Fourth Avenue in Anchorage, where half the street dropped about ten feet. US Geological Survey

  The tire that was pierced by a plank in Whittier during the earthquake. US Geological Survey

  Destroyed houses in the Turnagain Heights neighborhood in Anchorage. US Geological Survey

  Debris covered Sherman Glacier after a landslide that occurred when the peak of a nearby mountain broke off during the earthquake. US Geological Survey

  An area of the seafloor at Montague Island that rose up during the quake. The white color is from marine organisms that died when they were exposed to the air. US Geological Survey

  The village of Chenega, including the schoolhouse on the hill. Alaska State Library

  Village life in Chenega centered around the Russian Orthodox church. Courtesy of Kris Van Winkle

  Kris Madsen and her students put on a Christmas pageant in 1963, with the help of the lay priest Steve Vlasoff. Courtesy of Kris Van Winkle

  Survivors gathered on the hill above the schoolhouse after the quake. Courtesy of Kris Van Winkle

  Valdez from the air, looking toward the town docks, in 1962. Bob and Marie Logan slides, Archives and Special Collections, Consortium Library, University of Alaska Anchorage

  Little was left of the village homes and the church after the earthquake. Courtesy of Kris Van Winkle

  Valdez several days after the earthquake. At the bottom, the town docks are gone. National Oceanic and Atmospheric Administration/Department of Commerce

  George Plafker on Montague Island in Prince William Sound in 2015.

  Courtesy of the author

  The tire is about three feet in diameter and is mounted on a steel rim. It’s a heavy-duty one, built of ten rubberized layers, off a forklift truck. In the photograph, taken a few days after the earthquake at what remained of Two Brothers Lumber Company, a sawmill on the waterfront in Whittier, an unidentified man is standing behind it. With his left hand he is keeping the tire balanced upright. With his right he is gesturing, showing what happened to it. There’s no need for that, really, because what happened to the tire is plain to see, if scarcely believable. A two-inch-by-eight-inch plank is sticking through it, the lumber having gone clear into one sidewall and out the other. It’s as if the tire had been pierced by a giant, and very blunt, arrow.

  In the hours after the earthquake, dazed Alaskans tried to take stock of what had hit them. One thing was obvious: this was an earthquake with a power far greater than anyone in the state had experienced before. They would eventually learn that the Good Friday quake, as everyone took to calling it, had a power far greater than just about anyone anywhere had experienced before. No, an atomic bomb hadn’t hit the state, as some had initially thought, but by one quick calculation that was published in the newspapers in the days following the quake, the energy released was equivalent to thousands of A-bombs.

  The speared tire was just one of many artifacts that testified to the forces that had been unleashed—in this case, in the form of a thirty-foot wave that had struck the Whittier waterfront and sent a barge loaded with lumber careening into the sawmill. There were so many others: hemlocks that had been snapped in half at midtrunk height; spruces that were split vertically as the ground cracked beneath them; heavy equipment that had been moved hundreds of feet; hillsides that had been stripped bare of vegetation by the scouring action of water; one-ton boulders found halfway up slopes; roads split down the middle and sunk ten feet or more on one side; rail lines in tangles; brick building facades in jumbled heaps; cars upside down; homes upside down; boats littering streets. Some of the “artifacts” were enormous. Near Sherman Glacier, about twenty miles east of Cordova, the top 500 feet of a 4,300-foot-high mountain (later named Shattered Peak) broke away during the quake. In the ensuing landslide, an estimated twenty-five million cubic yards of rock hurtled down the mountain. With a thin cushion of air trapped beneath it that reduced friction, the rock debris reached speeds of two hundred miles an hour and traveled more than three miles. It eventually spread out over about five square miles of the glacier in a layer four feet thick, like the frosting on a cake, where it sits to this day.

  Stopped clocks showed that the quake had begun at 5:36 p.m. By most accounts, it had had a beginning, a middle and an end—starting slowly, quickly going into overdrive with violent rolling and jarring and then mercifully fading out. Estimates of the duration varied widely. A fisherman in Prince William Sound thought it lasted only a minute or two, while to at least one person, trapped inside an Anchorage store, it seemed that the nightmare had gone on for ten minutes or longer. The consensus, however, was that the shaking had lasted four to five minutes. Most agreed that, no matter the exact amount of time, it felt like forever. The earthquake had been unbearable.

  Scientists immediately tried to quantify the quake’s power, to put a number on what had scared Alaskans out of their wits. Initial reports were that it registered 8.2 to 8.7 on the Richter scale, putting it on a par with or stronger than the 1906 San Francisco earthquake, at least in terms of the energy released. The lowest number came from the seismological laboratory at the California Institute of Technology in Pasadena, from none other than Charles F. Richter himself, who with Beno Gutenberg had developed the scale that bore his name in the 1930s as a way of expressing the relative power of earthquakes. (In the 1950s, Richter had done some backward reasoning on the San Francisco quake and come up with 8.25 as its magnitude.)

  The Alaska earthquake had been centered, seismologists said, at a spot fifteen miles below the Chugach Mountains, near a long finger of Prince William Sound called Unakwik Inlet. Anchorage was seventy-five miles to the west and Valdez fifty-five to the east.

  It had made the earth ring like a bell, as one scientist later put it. Another likened the planet’s response to that of a struck tuning fork. The quake was picked up by seismographs all over the world, including about one hundred that had been installed since 1960 at government agencies and universities as part of what was called the World-Wide Standardized Seismograph Network. The network was funded by the US military’s research wing, DARPA, and its main purpose was to detect nuclear weapons tests, which produce seismic signals that are different from those of earthquakes. (Not surprisingly, the Soviet Union and its satellite states were not involved.) But the program had many benefits for peaceful science as well. The one working seismograph in Alaska at the time, in Fairbanks, was part of the network but had been overwhelmed by the power and proximity of the quake.

  Other instruments detected the event as well. As the shock waves traveled through the earth they caused groundwater levels to fluctuate. In the United States, gauges at more than seven hundred wells—including some as far away as Georgia, Florida and Puerto Rico—recorded changes. At an astounding twenty-three feet, a well in Belle Fourche, South Dakota, near the Wyoming line, had the biggest fluctuation of all. Outside of the United States, wells were affected in England, Belgium, Libya, Israel, South-West Africa (now Namibia) and Australia, among other countries. Rivers, streams, reservoirs and lakes showed temporary changes in level, too, at more than 750 surface-water gauging stations around the United States. Even the Gulf of Mexico was affected: the seismic waves caused seiches, oscillations in the water level, like water sloshing around in a bathtub. Some of the resulting waves were six feet high and caused minor damage to boats and docks.

  The earthquake was like a nuclear explosion in one respect: it had an effect on the atmosphere. The rapid land movement over such a huge area compressed the air above Alaska for a moment, causing a brief spike in air pressure that spread out in waves, like the ripples on a pond. Sensitive baromet
ers at the Scripps Institution of Oceanography near San Diego, nearly 2,500 miles from Anchorage, measured the slight pressure changes about three hours after the quake.

  Earthquakes are always followed by aftershocks, and this one was no exception. In the first twenty-four hours, seismographs recorded twenty-eight of them, including ten that at magnitude 6.0 or greater would qualify as strong earthquakes in their own right. By two months after Good Friday, some twelve thousand aftershocks greater than magnitude 3.5—meaning, generally, those that can be felt—had occurred. Aftershocks become less frequent and weaker over time, and that was the case with this quake. Still, over the next year and a half, there were thousands more small tremors before the region finally calmed down.

  In the first days after the quake, Alaskan officials began to tally the cost, both in lives and in property. Civil defense, Red Cross and Salvation Army representatives came up with initial estimates of one hundred or more dead and more than 450 injured. Federal emergency planning officials made an equally quick estimate of the cost to clean up and rebuild: up to half a billion dollars.

  If those figures seem low, remember that Alaska’s population at the time was only a quarter of a million and that its yearly gross state product—the value of all the goods and services produced—was only about $1 billion. If the quake had struck a more thickly settled region, or a more prosperous one, the toll in lives and property would have been vastly higher. Likewise, if it had struck earlier on a busy weekday instead of late on a holiday—when more people would have been out and about, at work or school or shopping—and at high tide rather than low tide, no doubt there would have been more death and destruction. In some ways, Alaska was lucky.

  While the quake was felt over a wide arc, major damage was confined to a lesser one, from Kodiak Island in the southwest up through Anchorage and southeast through Cordova, encompassing much of the Gulf of Alaska and all of Prince William Sound. This area included most of what would be considered “developed” Alaska. Most of the state’s infrastructure was here, and much of it was now in tatters. Valdez was not the only port to be effectively destroyed. At Seward, where cargo from the Lower 48 was unloaded (and where the Chena had stopped before Valdez), docks and warehouses were wiped out and oil tanks were in flames. At Whittier, Two Brothers Lumber was only one of many businesses that were gone, and the town’s oil tanks, too, had caught fire. The state’s fishing industry had been hit hard, with canneries and dock facilities heavily damaged or obliterated by high water around the sound and the Gulf of Alaska. The fishing port of Kodiak had also been swamped by tidal waves, and much of its fleet was now in its streets. Cordova suffered little direct damage, but a Coast Guard ship that arrived a day after the quake found changes: suddenly the harbor was not nearly as deep as before, and dredging would be needed before the town’s fishing fleet could operate efficiently there.

  Roads throughout the region were impassable, including the vital two-lane highway linking Seward and Anchorage. As George Plafker had seen in that first reconnaissance flight, it was blocked by landslides and avalanches, and many bridges had collapsed. The spur road from Portage to Whittier was in bad shape, too, although the 2.5-mile-long tunnel just on the landward side of Whittier, burrowed through Maynard Mountain by the army in the 1940s, appeared to have suffered no ill effects from the shaking.

  Even more devastating than the damaged roads, however, was the condition of the Alaska Railroad. South of Anchorage, the 470-mile-long line, the spine that tied the state together economically by bringing goods as far north as Fairbanks, was wrecked. Early estimates were that repairs would take months.

  Other links were cut. A section of the Million Dollar Bridge in the Copper River delta, which had been built for the railroad in the early 1900s to reach rich copper deposits (at the then unheard-of cost of nearly $1.5 million) but now served motorists, had been shaken off its foundations. Repairing it would be a gargantuan task. Anchorage’s international airport was out of commission. Other airfields had cracked runways.

  The military had its own problems. There were concerns about the Cold War communications infrastructure—that was one of the reasons the officers had been happy to see Plafker and the other geologists arrive the day after the quake. But commanders kept quiet about a more immediate and serious worry. Some of the army’s Nike Hercules missile batteries, which were designed to shoot Russian bombers out of the sky in the event of World War III, were damaged. There were three batteries around Anchorage, manned by crews from Fort Richardson, and two of them had suffered from the earthquake shocks. At one, at Fort Richardson itself, a large radar dish had shifted off its pedestal, and the army was looking at repairs that might take months.

  But far more ominous was what happened at a battery just off the end of the main runway of the Anchorage airport. Some of the forty-foot-long missiles, stored in aboveground bunkers, had toppled during the quake, cracking open and spilling highly flammable solid rocket fuel. The danger of an explosion and fire was high, and adding to the risk was a characteristic of the missiles that the army didn’t talk about: they carried nuclear warheads.

  Although the warhead on each missile was about one-third more powerful than the bomb that had destroyed Hiroshima, there wasn’t much danger of Anchorage going up in a nuclear fireball. But the risk of radioactive contamination—of a conventional explosion that could send some of the warhead’s radioactive plutonium into the air, to eventually settle across the city and elsewhere—was very real. The military immediately took care of the problem, sending in a crew of soldiers who worked virtually nonstop over three days and amid the occasional aftershock to delicately clean up the mess.

  But civilian Alaska needed help, too, and fast. The army and air force were mobilized. Personnel and supplies were flown in from bases in the Lower 48, and relief flights fanned out to the areas where damage had been reported.

  In Anchorage, where power was out, troops roamed a thirty-square-block area as rescue and recovery efforts got under way. Fire department and other rescue units started a house-by-house search in Turnagain Heights, with victims being taken away in ambulances and private cars. Military helicopters swooped overhead, trying to spot survivors amid the jumbled blocks of earth. Downtown was a disaster, with the devastation on Fourth Avenue and the rubble of the facade of the J. C. Penney store littering Fifth Avenue. Search-and-rescue teams went through every building, but the Penney store was so big, and its damage so severe, that it required a dedicated team of searchers.

  One elementary school was a total loss, and a hospital for the native population narrowly escaped destruction when land nearby gave way. In addition to the unfinished apartment building that collapsed, two identical, and occupied, fourteen-story residential towers were damaged. A large hotel, the Westward, just a few blocks from Fourth Avenue, seemed fine from the exterior, but the internal structure was severely damaged. In all three buildings, amazingly, no one was injured.

  Amid the devastation there was the occasional odd, calming sight, like the small clothing store where the display windows had shattered and a group of mannequins now leaned out onto the street, or the florist’s shop with the fresh flowers still sitting in their vases. The Denali movie theater, despite having dropped about ten feet when Fourth Avenue cracked and slid, had not suffered a single broken lightbulb on its marquee.

  In the slide at Turnagain Heights—the one Bob Atwood lived through—about seventy-five of the neighborhood’s homes were destroyed. The scale of the slide was enormous: two hundred acres of land had moved as much as two thousand feet toward the water. Even some land under the water had moved. But Turnagain was only the largest of several slides in Anchorage. The damage on Fourth Avenue downtown was due to a smaller one, and the school that was destroyed had been brought down, literally, by a slide on Government Hill, on the other side of Ship Creek. The school had split in two, and one half had dropped a dozen feet below the other.

  Most of the damage from the quake, in Anchorage and el
sewhere, was caused, not directly by shaking, but rather indirectly by the effects the shaking had on soil and sediments. The destruction of the waterfront at Valdez was the most obvious example, as the sediments that the dock sat on turned to jelly and slumped during the quake. Seward appeared to suffer roughly the same fate, with a big chunk of the waterfront sloughing into the water. The Anchorage slides were evidence of movement as well, but the action was a little different. The sliding occurred in a layer of fine and slick sediments known as Bootlegger Cove Clay. The soil above was carried along by this sliding clay layer, which is why at Turnagain Heights it broke into large blocks that moved about crazily and nearly killed Atwood.

  No one was certain yet, but the waves that had hit Chenega appeared to have been caused by an underwater landslide of nearby sediments deposited by glaciers. That would explain why the first wave arrived while the ground was still shaking. Whittier appeared to have been hit by such a locally generated tidal wave as well.

  But there were other, much farther-reaching tidal waves spawned not by landslides but by the ground movement along the fault—in other words, by the earthquake itself. (In their circular published a month after the earthquake, Plafker and his colleagues referred to these as “seismic sea waves.”) These traveled far across the Pacific at hundreds of miles an hour, even reaching the Antarctic Peninsula, ten thousand miles away.

  When a tidal wave is out in the deep ocean, it has little or no effect on the surface. Such a wave can pass under ships without their crews realizing it. But when it approaches land, local conditions—the topography of an inlet, say, or the contours of the bottom of a bay—can have an enormous impact, focusing the wave energy. Waves can grow taller and can slow to a tenth of their initial speed or slower.