David A. Johnston

Johnston going into the Mount St. Helens crater to sample the lake. Photographed on April 30, 1980.

Johnston sampling the lake.

Since its last eruptive activity in 1857, Mount St. Helens had been largely dormant. Seismographs were not installed until 1972. This period of 123 years of inactivity ended in early 1980. On March 15, a cluster of tiny earthquakes rocked the area around the mountain. For six days, more than 100 earthquakes clustered around Mount St. Helens, an indication that magma was moving. There was initially some doubt as to whether the earthquakes were precursors to an eruption.[11] By March 20, a magnitude 4.2 earthquake shook the wilderness around the volcano. The next day, seismologists installed three seismic recorder stations.[12] By March 24, volcanologists at the USGS—including Johnston—became more confident that the seismic activity was a sign of an impending eruption. After March 25, seismic activity drastically increased. By March 26, more than seven earthquakes over magnitude 4.0 had been recorded, and the next day, hazard warnings were publicly issued.[11] On March 27, a phreatic eruption took place, ejecting a plume of ash nearly 7,000 feet (2,100 m) into the air.[11]

Similar activity continued at the volcano over the following weeks, excavating the crater, forming an adjacent caldera, and erupting small amounts of steam, ash, and tephra. With each new eruption, the plumes of steam and ash from the volcano rose, eventually climbing to 20,000 feet (6,000 m). By late March, the volcano was erupting up to 100 times per day.[13] Spectators congregated in the vicinity of the mountain, hoping for a chance to see its eruptions. They were joined by reporters in helicopters, as well as mountain climbers.[13]

On April 17, a bulge (or "cryptodome") was discovered on the mountain's north flank, suggesting that Mount St. Helens could produce a lateral blast.[14] Rising magma under Mount St. Helens had veered off to the north flank, creating a growing bulge on the surface.[14]

Given the increasing seismic and volcanic activity, Johnston and the other volcanologists working for the USGS in its Vancouver branch prepared to observe any impending eruption. Geologist Don Swanson and others placed reflectors on and around the growing domes,[15] and established the Coldwater I 46°17′55.8″N 122°17′22.9″W and II 46°16′37.5″N 122°13′28.0″W observation posts to use laser ranging to measure how the distances to these reflectors changed over time as the domes deformed. Coldwater II, where Johnston died, was located just 6 miles (10 km) north of the mountain. To the astonishment of the USGS geologists, the bulge was growing at a rate of 5 to 8 feet (1.5 to 2.4 meters) per day.[16]

Johnston (center) climbing into the summit crater of Mount St. Helens to sample gases. For the scale, see this picture.

Tiltmeters installed on the volcano's north side displayed a northwest trending tilt for that side of the mountain, and a southwest trending tilt was observed on the south side. Worried that the amount of pressure on the magma underground was increasing, scientists analyzed gases by the crater, and found high traces of sulfur dioxide. After this discovery, they began to regularly check the fumarolic activity and monitor the volcano for dramatic changes, but none were observed. Disheartened, they instead opted to study the growing bulge and the threat an avalanche could have for humans relatively near the volcano.[17] An evaluation of the threat was carried out, concluding that a landslide or avalanche in the Toutle River could spawn lahars, or mudflows, downstream.[14]

At that point, the previously consistent phreatic activity had become intermittent. Between May 10 and 17, the only change occurred on the volcano's north flank, as the bulge increased in size. On May 16 and 17, the mountain stopped its phreatic eruptions completely.[17]

Mount St. Helens one day before the eruption, photographed by Harry Glicken from the ridge where the Coldwater II observation post occupied by Johnston was located.

Mount St. Helens four months after the eruption, photographed by Harry Glicken from approximately the same location as the earlier picture. In the intervening period, the volcano had erupted, killing Johnston and approximately 60 others, devastating the landscape.

The active Mount St. Helens was radically different from its dormant form, now featuring an enormous bulge and several craters. In the week preceding the eruption, cracks formed in the north sector of the volcano's summit, indicating a movement of magma.[17]

At 8:32 a.m. local time the next day (May 18), an earthquake measuring magnitude 5.1 rocked the area, triggering the landslide that started the main eruption. In a matter of seconds, vibrations from the earthquake loosened 2.7 cubic kilometers (0.6 cu mi) of rock on the mountain's north face and summit, creating a massive landslide.[18] It was the largest subaerial (on land) landslide in Earth's recorded history.[19] With the loss of the confining pressure of the overlying rock, Mount St. Helens began to rapidly emit steam and other volcanic gases. A few seconds later, it erupted laterally, sending swift pyroclastic flows down its flanks at near supersonic speeds. These flows were later joined by lahars.[20] Before being struck by a series of flows that, at their fastest, would have taken less than a minute to reach his position 46°17′37″N 122°13′27.1″W, Johnston attempted to radio his USGS co-workers with the message: "Vancouver! Vancouver! This is it! Vancouver, is the transmitter on?" The cloud of the eruption blocked the transmission of his message to Vancouver; his final words were recorded by a HAM radio operator. Seconds later, the signal from the radio went silent, and all contact with the geologist was lost.[21] Initially, there was some debate as to whether Johnston had survived; records soon showed a radio message from fellow eruption victim and amateur radio operator Gerry Martin, located near the Coldwater peak 46°17′59.7″N 122°12′55″W and farther north of Johnston's position, reporting his sighting of the eruption enveloping the Coldwater II observation post. As the blast overwhelmed Johnston's post, Martin declared solemnly: "Gentlemen, the camper and car that’s sitting over to the south of me is covered. It’s going to hit me, too." before his radio too went silent.[22][23]

The extent, speed and direction of the avalanche and pyroclastic flows that overwhelmed Johnston, Martin, and others were later described in detail in a paper titled 'Chronology and Character of the May 18, 1980 Explosive Eruptions of Mount St. Helens', published in 1984 in a collection published by the National Research Council's Geophysics Study Committee.[24] In this paper, the authors examined photographs and satellite images of the eruption to construct a chronology and description of the first few minutes. Included in the paper is figure 10.3, a series of timed photographs taken from Mount Adams, 33 miles (53 km) east of Mount St. Helens. These six photographs, taken sideways on to the lateral blast, vividly show the extent and size of the avalanche and flows as they reached northwards over and beyond Johnston's position. Figure 10.7 from the same paper is an overhead diagram showing the position of the pyroclastic surge front at half-minute intervals, with the positions of Johnston (Coldwater II) and Martin included.[24]

The eruption was heard hundreds of miles away,[25] but some of those who survived the eruption declared that the landslide and pyroclastic flows were silent as they raced down the mountain. Kran Kilpatrick, an employee of the United States Forest Service, recalled, "There was no sound to it, not a sound. It was like a silent movie and we were all in it."[26] The reason for this discrepancy is a "quiet zone", created as a result of the motion and temperature of air and, to a lesser extent, upon local topography.[25]

Famous for telling reporters that being on the mountain was like "standing next to a dynamite keg and the fuse is lit",[27] Johnston had been among the first volcanologists at the volcano when eruptive signs appeared, and shortly after was named the head of volcanic gas monitoring. He and several other volcanologists prevented people from being near the volcano during the few months of pre-eruptive activity, and successfully fought pressure to re-open the area.[9] Their work kept the death toll at a few tens of individuals, instead of the thousands who possibly could have been killed had the region not been sealed off.

Johnston's Coldwater II observation post was in the path of the blast when the north side of Mount St. Helens collapsed.

Many USGS scientists worked on the team monitoring the volcano, but it was graduate student Harry Glicken who had been manning the Coldwater II observation post for the two and a half weeks immediately preceding the eruption.[28] The evening before the eruption he was scheduled to be relieved by USGS geologist Don Swanson, but something came up, and Swanson asked Johnston to take his place. Johnston agreed. That Saturday, the day before the eruption took place, Johnston ascended the mountain and went on a patrol of the volcano with geologist Carolyn Driedger. Tremors shook the mountain. Driedger was supposed to camp on one of the ridges overlooking the volcano that night, but Johnston told her to head home and said that he would stay on the volcano alone.[29] While at Coldwater II, Johnston was to observe the volcano for any further signs of an eruption.[30] Just prior to his departure, at 7 p.m. on the evening of May 17, 13½ hours before the eruption, Glicken took the famous photograph of Johnston sitting by the observation-post trailer with a notebook on his lap, smiling.[17]

The following morning, May 18, at 8:32 a.m.,[31] the volcano erupted. Immediately, rescue workers were dispatched to the area. The official USGS pilot, Lon Stickney, who had been flying the scientists to the mountain, conducted the first rescue attempt. He flew his helicopter over the scarred remains of trees, valleys, and the Coldwater II observation post ridge, where he saw bare rock and uprooted trees. Because he saw no sign of Johnston's trailer, Stickney began to panic, becoming "emotionally distraught".[32]

Frantic and guilt-stricken, Harry Glicken convinced three separate helicopter pilots to take him up on flights over the devastated area in a rescue attempt, but the eruption had so changed the landscape that they were unable to locate any sign of the Coldwater II observation post. In 1993, while building a 9-mile (14 km) extension of Washington State Route 504 (also called "Spirit Lake Memorial Highway") to lead to the Johnston Ridge Observatory, construction workers discovered pieces of Johnston's trailer.[33] His body, however, has never been recovered.[34]

The public was shocked by the extent of the eruption, which had lowered the elevation of the summit by 1,313 feet (400 m), destroyed 230 square miles (600 km²) of woodland, and spread ash into other states and Canada.[35] The lateral blast that killed Johnston started at a speed of 220 miles per hour (350 km/h) and accelerated to 670 miles per hour (1,080 km/h).[25] Even USGS scientists were awed. With a Volcanic Explosivity Index value of 5, the eruption was catastrophic. More than 50 people were killed or missing, including Johnston, mountain resident Harry R. Truman, photographer Robert Landsburg, and National Geographic photographer Reid Blackburn.[35]

The disaster was the deadliest and most destructive volcanic eruption in the history of the United States of America. A total of 57 people are known to have died, and more were left homeless when the ash falls and pyroclastic flows destroyed or buried 200 houses. In addition to the human fatalities, thousands of animals perished. The official estimate from the USGS was 7,000 game animals, 12 million salmon fingerlings, and 40,000 salmon.[35]

Two years after the eruption, the United States government set aside 110,000 acres (450 km²) of land for the Mount St. Helens National Volcanic Monument. This protected area, which includes the Johnston Ridge Observatory and several other research and visitor centers, serves as an area for scientific research, tourism, and education.[36]

Johnston Ridge from the Johnston Ridge Observatory in July 2005, showing new plant growth among dead trees from the eruption 25 years earlier

Johnston Ridge from a proximate location in July 2016, showing continued plant growth in the region

Johnston was commemorated by both his fellow scientists and by the government. Known for his diligent and particular nature, he was called "an exemplary scientist" by a USGS dedication paper, which also described him as "unaffectedly genuine, with an infectious curiosity and enthusiasm".[9] He was quick to "dissipate cynicism" and believed that "careful evaluation and interpretation" was the best approach to his work.[9] An obituary notice for Johnston stated that at the time of his death he had been "among the leading young volcanologists in the world" and that his "enthusiasm and warmth" would be "missed at least as much as his scientific strength".[37] Following the eruption, Harry Glicken and other geologists at the USGS dedicated their work to Johnston.[38]

Because Johnston was believed to be safe at the Coldwater II observation post, the fact that he died shocked his friends and co-workers alike. However, most of his colleagues and family asserted that Johnston died "doing what he wanted to do."[4] His mother stated in an interview shortly after the eruption, "Not many people get to do what they really want to do in this world, but our son did. ... He would tell us he may never get rich but he was doing what he wanted. He wanted to be near if the eruption came. In a phone call on Mother's Day, he told us it's a sight very few geologists get to see."[4] Dr. Stephen Malone agreed that Johnston died doing what he loved, and stated that he "was very good at his work".[10]

Johnston's role in the study of the volcano in the weeks leading up to the eruption was acknowledged in 1981 in a chronology of the eruption, published as part of the USGS report titled 'The 1980 Eruptions of Mount St. Helens, Washington':

Among the many contributors of data, none was more essential to the systematic reconstruction of the events of 1980 at Mount St. Helens than David Johnston, to whose memory this report is dedicated. Dave, who was present through all of the activity up to the climactic eruption and who lost his life in that eruption, provided far more than data. His insights and his thoroughly scientific attitude were crucial to the entire effort; they still serve as a model for us all.

— R. L. Christiansen and D. W. Peterson, Chronology of the 1980 Eruptive Activity[39]

Johnston Ridge Observatory (JRO) in December 2005

Since Johnston's death, his field of volcanic eruption prediction has advanced significantly, and volcanologists are now able to predict eruptions based on a number of precursors that become apparent between days and months in advance.[40] Geologists can now identify characteristic patterns in seismic waves that indicate particular magmatic activity.[41] In particular, volcanologists have used deep, long-period earthquakes that indicate that magma is rising through the crust. They can also use carbon dioxide emission as a proxy for magma supply rate. Measurements of surface deformation due to magmatic intrusions, like those that were conducted by Johnston and the other USGS scientists at the Coldwater I and II outposts, have advanced in scale and precision. Ground deformation monitoring networks around volcanoes now consist of InSAR (interferometry), surveys of networks of GPS monuments, microgravity surveys in which scientists measure the change in gravitational potential or acceleration because of the intruding magma and resulting deformation, strain meters, and tiltmeters. Though there is still work to be done, this combination of approaches has greatly improved scientists' abilities to forecast volcanic eruptions.[40]

In addition to his work, Johnston himself has become part of the history of volcanic eruptions. With Harry Glicken, he is one of two volcanologists from the United States to die in a volcanic eruption.[42] Glicken was being mentored by Johnston, who relieved Glicken of his watch at the Coldwater II observation post 13 hours before Mount St. Helens erupted.[28] Glicken died in 1991, eleven years later, when a pyroclastic flow overran him and several others at Mount Unzen in Japan.[42][43]

Sign showing the full and official name of the David A. Johnston Cascades Volcano Observatory (CVO)

Early acts of commemoration included two trees that were planted in Tel Aviv, Israel,[8] and the renaming of a community center in Johnston's hometown as the "Johnston Center". These actions were reported in newspapers during the first anniversary of the eruption in May 1981.[8][44]

On the second anniversary of the eruption, the USGS office in Vancouver (which had been permanently established following the 1980 eruption) was renamed the David A. Johnston Cascades Volcano Observatory (CVO) in his memory.[45] This volcano observatory is the one most responsible for monitoring Mount St. Helens, and helped to predict all of the volcano's eruptions between 1980 and 1985.[46] In a 2005 open day, the lobby area of the CVO included a display and painting commemorating Johnston.[47]

Johnston's connections with the University of Washington (where he had carried out his masters and doctoral research) are remembered by a memorial fund that established an endowed graduate-level fellowship within what is now the department of Earth and Space Sciences. By the time of the first anniversary of his death, the fund had exceeded $30,000. Known as the 'David A. Johnston Memorial Fellowship for Research Excellence', a number of awards of this fellowship have been made over the years since it was launched.[8][48]

Following the eruption, the area where the Coldwater II observation post had been was sectioned off. Eventually, an observatory was built in the area in Johnston's name, and opened in 1997.[49] Located just over 5 miles (8 km) from the north flank of Mount St. Helens, the Johnston Ridge Observatory (JRO) allows the public to admire the open crater, new activity, and the creations of the 1980 eruption, including an extensive basalt field. Part of the Mount St. Helens National Volcanic Monument, the JRO was constructed for $10.5 million, equipped with monitoring equipment. Visited by thousands of tourists annually, it also includes tours, a theater, and an exhibit hall.[50]

There are several public memorials where Johnston's name is inscribed in a list of those known to have died in the eruption. These memorials include a large curved granite monument at an outside viewing area at the Johnston Ridge Observatory, which opened in 1997, and a plaque at the Hoffstadt Bluffs Visitor Center, which was unveiled in a memorial grove in May 2000.[51]

A granite memorial inscribed with the names of the victims of the May 18, 1980, eruption, photographed on the 27th anniversary of the blast. David Johnston's name can be seen beneath the rose, slightly to the left.

There have been several tellings of Johnston's story in documentaries, films and docudramas about the eruption.

In the 1981 HBO television film St. Helens, actor David Huffman starred as David Jackson, a fictional character supposedly based on Johnston, but with almost no representation of his actions in 1980. Johnston's parents objected to the production of the film, arguing that it possessed not "an ounce of David in it" and portrayed "him as a daredevil rather than a careful scientist".[21] Johnston's mother stated that the film had changed many true aspects of the eruption, and depicted her son as "a rebel" with "a history of disciplinary trouble".[21] Prior to the film's premiere on May 18, 1981, the first anniversary of the eruption, 36 scientists who knew Johnston signed a letter of protest. They wrote that, "Dave's life was too meritorious to require fictional embellishments," and that, "Dave was a superbly conscientious and creative scientist."[52]  

Several documentaries and docudramas have covered the history of the eruption, including archive footage and dramatisations of Johnston's story. These include Up From the Ashes (1990) by KOMO-TV, an episode of the 2005 second series of Seconds From Disaster broadcast by the National Geographic Channel,[53] an episode of the 2006 series Surviving Disaster made by the BBC,[54] and the episode "Rescued From Mount St. Helens" from the 2017 series We'll Meet Again with Ann Curry on PBS.[55]