First Hand Accounts:
Keith stofell:
"Noticed land sliding of rock and ice debris in-ward into the crater... the south-facing wall of the north side of the main crater was especially active. Within a matter of seconds, perhaps 15 seconds, the whole north side of the summit crater began to
move instantaneously. ... The nature of movement was eerie.... The entire mass began to ripple and churn up, without moving laterally. Then the entire north side of the summit began sliding to the north along a deep-seated slide plane. I (Keith Stoffel)
was amazed and excited with the realization that we were watching this landslide of unbelievable proportions. ... We took pictures of this slide sequence occurring, but before we could snap off more than a few pictures, a huge explosion blasted
out of the detachment plane. We neither felt nor heard a thing, even though we were just east of the summit at this time."
What was the response to the eruption?
On May 21st president Jimmy Carter visited Mount St. Helens.
The president flew over mount St Helens, at 6:35pm the president arrived at Portland International Airport in Oregon. State and local officials and press greeted him.
He said to the press "The moon looks like a golf course compared to what’s up there; its the worst thing I’ve ever seen."
He went to the federal building in Vancouver with two governors; the president was briefed on the damage caused by the eruption. The president then went on a tour of the federal building that had been converted into a disaster relief command centre.
The president then went to his hotel.
Ash removal cost $2.2 million and took 10 weeks in Yakima. They used landfill sites and disused quarries for dumping. The total ash was estimated to weigh 900,000 tons.
On May 23rd The Federal Emergency Management Agency (FEMA) officially set up the disaster relief command centre in Vancouver. Which they would be using for the next eight months.
On July 2nd the U.S congress gave $951 million dollars in disaster relief funds of which the largest share went to the Small Business Administration, U.S. Army Corps of Engineers, and the Federal Emergency Management Agency.
The following is a log of Mount St. Helens Precursory Activity from the USGS from 20th March to 17th May
The following text is not my own, and is taken from the USGS website
Seismologists did not monitor earthquake activity at Mount St. Helens until seismometers were installed near the volcano in 1972. From January 1975 through early 1980 only 44 earthquakes were located within 35km of the volcano.
The most recent period of unrest began on March 15, 1980. From the 15th through the 21st over 100 earthquakes were recorded. It was a magnitude 4.1 earthquake recorded on March 20 that provided scientists with the first signal that Mount St.Helens might erupt for the first time since 1857.
March 20 - At approximately 3:45 PM a magnitude 4.1 earthquake occurred just northwest of the summit of Mount St. Helens at shallow depth. It was unlike any that had been previously detected in the area. Ground shaking from the earthquake triggered snow avalanches on some flanks of the volcano. Seismologists were uncertain as to whether or not these first earthquakes were related to volcanic activity. They decided to deploy additional seismometers in order to monitor future activity better.
March 21 - Earthquake activity increased. University of Washington seismologists warned the US Forest Service that continued ground shaking from large earthquakes could cause new avalanches. Although seismologists were suspicious the earthquakes might be related to volcanic activity, they did not say so publicly. Three new portable seismic recorder stations and one radio-telemetered seismic station were installed. These stations were needed to determine more precisely the location, and more importantly, the cause of the earthquakes. Seismologists also consulted with the US Geological Survey about the current earthquake activity. Over the next week, people were worried about earthquake-triggered avalanches would make the USFS to close the mountain above tree line.
March 22 - A second earthquake larger than magnitude 4.0 occurred beneath Mount St. Helens. UW seismologists concluded that this was not an earthquake-aftershock sequence, but rather a swarm of individual earthquakes. The danger from earthquake-triggered avalanches remained high.
March 23 - UW seismologists visited the three new portable seismic data recorder units to retrieve data today, but were frustrated as the stations were not functioning properly. Other telemetered data showed a sharp increase in activity, including 5 earthquakes larger than magnitude 3.0 and one larger than magnitude 4.0. UW seismologists determined that the current earthquake sequence could be precursory to volcanic activity.
March 24 - Earthquake activity continued to increase, with 10 earthquakes larger than magnitude 3.0 and 4 larger than magnitude 4.0 (including one of magnitude 4.7). The University of Washington seismology lab was being staffed 24 hours a day to handle the amount of incoming data.
March 25 - Five earthquakes larger than magnitude 4.0 occurred within a one hour period and as many as 22 occurred within one 8 hour period (the total number of earthquakes larger than magnitude 4.0 was 25). As of 1PM earthquakes occurred so frequently that the record for seismic station SHW became saturated. Individual earthquakes with a magnitude less than 3.5 were lost due to the continuous traces of larger ones. Donal Mullineaux, co-author of the USGS Bulletin "Future Eruptions of Mount St. Helens, Washington," left Denver for Vancouver to advise the USFS and local officials on the developing situation. USFS officials closed the Spirit Lake Information Centre, access to the mountain above tree line, and several forest roads leading to Mount St. Helens. Due to increased interest from the media, photographers and scientists, the FAA imposed special flight restrictions near the volcano. Bud Kimball, a commercial aerial photographer, reported to the USGS office in Tacoma that he had photographed a large crack in the snow across the top of the volcano.
March 26 - The University of Washington recorded the 100th earthquake larger than magnitude 3.5, as well as 7 larger than magnitude 4.0. Depths for most quakes were less than 3 miles. Additional recording equipment was installed at the UW Seismology Lab to handle the amount of incoming data. Seismologists were working around the clock to locate earthquakes. Federal, state, and county emergency services officials met in Vancouver to hear USGS scientists explain their interpretation of the recent seismic events and potential hazards.
March 27 - USGS officials issued a Hazards Watch to public officials. At 11:20AM an observer in an Army National Guard reconnaissance plane reported seeing a hole in the icecap near the summit and a grey streak extending southeast from the hole. At approximately 12:30 people near the volcano reported hearing a loud "boom," which probably marked the first sighted explosion. Mike Beard, a Portland radio reporter, was flying over the cloud-shrouded mountain and reported seeing "ash and smoke spewing out, a little like smoke out of a chimney." At 2:00PM UW seismologists recorded the second strongest earthquake to date (a magnitude 4.7). Following the earthquake a black plume was observed to rise about 7,000 feet above the volcano.
Earthquakes occurred so frequently that one University of Washington seismologist was quoted as saying the instruments had detected earthquakes so often that it "was difficult to tell where one ends and another begins."
Following the explosion a crater about 200 to 250 feet wide was reported near the summit. A series of cracks criss-crossed the summit from east to west and volcanic ash had darkened snow in a band across the crater and down the volcano's southeast slope.
Concerns over the increased potential for large rock avalanches (as a result of the cracks forming near the summit) and widespread flooding (due to heat from the volcano melting snow and ice) prompted the evacuation of hundreds within a 15-mile radius from the volcano. Among these were USFS employees and their families at the Pine Creek Ranger Station at the head of Swift Reservoir, 300 or so loggers from three Weyerhaeuser camps, and 20 employees from the state fish hatchery about 30 miles downstream on the North Fork Toutle River. Skamania County Sheriffs also evacuated about 45 people, mostly scientists and reporters, from the Spirit Lake area while Cowlitz County Sheriffs evacuated those further downstream on the North Fork Toutle River. Skamania County Sheriffs established a roadblock on State Route 504 approximately 7 miles from the volcano. By evening, however, USGS hydrologists had determined that there was no rise in streams draining the volcano.
Additional scientists arrived in the evening to study the continued seismic activity, measure possible ground deformation on the volcano, determine the chemical composition of volcanic ash and gases, and to monitor heat emissions, water levels and water quality.
Pacific Power and Light began drawing down all three reservoirs on the Lewis River on the south side of the volcano to accommodate flooding and mudflows from a possible eruption. Company representatives stated that the dams should withstand the most severe earthquakes expected in the area. The Oregon Museum of Science and Industry installed a seismograph exhibit with an expert on duty to field questions.
March 28 Another interval of frequent phreatic explosions began at 3AM and lasted nearly 2 hours. Observations were hampered by darkness and bad weather, but airborne observers saw a cloud of ash and steam that rose more than a mile above the volcano. By nightfall at least 12 additional explosions had occurred, with columns of steam and ash reaching to nearly 10,000 feet above the mountain. One that occurred just before sunset threw out rocks as large as 3 feet onto the flanks of the volcano and sent ash as far east as Trout Lake (35 miles). Several ash-darkened avalanches were visible on the east flank. Some reached the 6400-foot level near the Plains of Abraham. Some observers mistook these for lava or mudflows, further adding to concerns of flooding in valleys draining the mountain.
Scientists from the University of Washington Cloud Physics Group flew over the volcano to collect samples of escaping gases. They found that sulphur dioxide was the main species of sulphur present. This was the first indication that a high-temperature magmatic source was releasing gas during explosions from somewhere inside the volcano. Scientists flew to the 4,000 foot level despite bad weather to collect ash samples for analysis to determine whether the volcanic ash was from new magma or older, pulverized rock.
March 29 - A second crater formed to the west of the first and was visible on the morning of the 29th. Steam and ash mainly vented from this new crater. There were 86 earthquakes larger than magnitude 3.0 and 39 earthquakes between magnitude 3.5 and 4.4 recorded. USGS hydrologists have detected no unusual increase in stream flow, but noted a slight acidification of surface waters in areas contaminated with ash from earlier explosions. Throughout the night a blue flame was observed intermittently in the older crater or jumping between the old and new craters. According to USGS Geologist David Johnston, the flame was likely a result of the emission of a flammable gas, probably hydrogen sulphide.
March 30 - Ninety three explosions of steam and ash were observed. Ash from some of these reached the towns of Cougar and Stevenson to the southeast and was detected as far away as Mount Jefferson. Light ash fall in the Bull Run Watershed near Mount Hood prompted official concern at the Portland Water Bureau over possible acidification of the city's water supply. There were 58 earthquakes larger than magnitude 3.0, including 6 larger than magnitude 4.0. A group from Dartmouth College began remote measurements of sulphur dioxide (SO2). Early results showed the volcano emitted about 0.3 tons per day, which verified the identification of sulphur dioxide detected on the 28th. USGS scientists installed a tiltmeter near the volcano.
A carnival-like atmosphere prevailed around Mount St. Helens. By afternoon as many as 70 aircraft were reportedly flying around the volcano at the same time. At the Yale Reservoir boat launch over 300 cars were parked as sightseers sought a good view of the mountain. From Interstate 5 to the roadblock at mile 35 on State Route 504, vehicles lined both sides of the road at vantage points such as Silver Lake.
March 31 - Both craters enlarged as explosions continued. A change in wind direction brought ash to the Kelso-Longview area by noon. To date none of the ash from these explosions has come from new magma, but rather pulverized bits of older rocks that make up the summit. The frequency of earthquakes has decreased but the number of larger earthquakes has increased, so the total energy release remained about the same. Among these were two earthquakes of magnitude 4.6. Explosions and earthquakes triggered two avalanches of snow and rock near the Goat Rocks dome.
Cowlitz County Commissioners declared a state of emergency in an attempt to obtain assistance from the Washington National Guard in staffing roadblocks. According to a report in the Longview Daily News, Colonel Val E. McCreary (commander of the WA National Guard) announced that 300 troops, 50 trucks and 3 helicopters were on standby in case Governor Ray ordered evacuations. The Washington Department of Emergency Services (WADES) pressed the Clark County Amateur Radio Club into service as a backup communications network should the primary network maintained by the USFS fail.
Public response to the activity varied. The Vancouver Columbian reported that USFS personnel had fielded calls from frustrated citizens who could not access their cabins within closed areas while members of the press had been allowed in. Other calls ranged from gamblers requesting the number of explosions in the previous 24 hours to those blaming the volcano's restlessness on the desecration of Indian graves in the area.
Harry Truman began his climb to media folk-hero status due to extensive coverage in newspapers and television. He is the only person who has refused to leave his home on the south shore of Spirit Lake. A Longview Daily News article quoted Harry as saying, "I think the whole damn thing is over exaggerated...Spirit Lake and Mount St. Helens are my life...You couldn't pull me out with a mule team."
April 1 - Several plumes from explosions reached altitudes of 20,000 feet. Ash fall was reported south of the mountain in Cougar and as far away as the outskirts of Vancouver. Some observers claimed these were the strongest explosions to date. Ongoing explosive activity has caused the two craters to merge into one single crater over 600 feet across. A block of the summit bounded by two crack systems has sunk at least 200 feet. The settling has caused noticeable outward displacement, or bulging, of the rocks and ice north of the crater. Two earthquakes of magnitude 4.7 occurred, as well as the first weak harmonic tremor.
The occurrence of larger earthquakes accompanied by harmonic tremor, more vigorous explosions, and presence of sulphur dioxide led scientists to suggest that there is an increased possibility of an eruption involving magma. Attempts to obtain aerial photographs of the mountain were unsuccessful due to poor weather. Scientists would like photos to compare with similar ones taken in 1979 to help determine the physical changes that have occurred.
Cowlitz and Skamania County officials decided to ask the Washington National Guard for assistance. The two counties have been maintaining six roadblocks around the clock since March 27. They estimate that because of the extensive network of logging roads, they would need as many as 29 roadblocks and 175 officers to completely block off access. Nolan Lewis, Director of Cowlitz County Emergency Services, was quoted in the Tacoma News Tribune, “I just can't fathom it, people are swarming in from all over, putting their lives in danger... Sunday when the weather was clear, the road up to the mountain looked like downtown Seattle at rush hour."
Federal Aviation Administration (FAA) officials transferred control of air traffic operations around Mount St. Helens to their Seattle centre. In a Vancouver Columbian article, an FAA spokesman said that an estimated 100 planes were in the controlled area at times. Aircraft have maintained radio silence and illegally entered the restricted area from all directions and altitudes. According to a Longview Daily News article, one pilot reported, “It was like a dog fight over the crater last Thursday (March 27) before the Forest Service started its air control." About 300 loggers returned to work in areas northwest of the volcano.
April 2 - At least 12 plumes of steam and ash were observed above the mountain. One reached an altitude of 20,000 feet. Light ash fall was reported in Portland and Vancouver. At least one explosion threw out chunks of ice that fell to the west of Spirit Lake. There were 63 earthquakes larger than magnitude 3.0, including 5 larger than 4.0 (the largest was magnitude 4.8). A stronger burst of harmonic tremor was recorded between about 7:35 and 7:50 AM. The 2nd would turn out to be the most active day for earthquakes with magnitudes greater than 3.0 for the entire month of April.
Ash fall from the continuing explosions caused concern for US Fish and Wildlife Officials at the Wind River and Carson National Salmon Hatchery. According to an article in the Longview Daily News, water normally a pH of 6.8 had decreased to 6.1 in the river and to 5.8 in the hatchery water. Water with a pH of 5.5 would begin to cause extreme stress to the fish. Fish would begin to die in water with at a pH of 5. Operators said they plan to release the hatchlings if the water reaches a pH of 5.5.
Cowlitz County deputies abandoned roadblocks as the day ended. According to an article in The Oregonian, the State Department of Emergency Services (WADES) claimed the counties had not supplied all the information needed in order to offer assistance. Officials from both Cowlitz and Skamania County were critical of the state's response. The State Patrol took over manning the roadblock on State Route 504 while Skamania County continued to man roadblocks on State Route 503 and road N73 north of Carson.
The USFS sent 30 moving vans to the St. Helens Ranger District compound to remove the personal possessions of 37 Forest Service employees who had been evacuated March 27.
A Boston television producer was fired after airing an April Fool's Day story about a popular ski resort that had turned into a raging volcano. It included video footage of explosions from St. Helens.
April 3 - Explosions sent plumes upwards from the crater almost hourly. Ash was reported in and near Tacoma, 70 miles to the north. Some plumes reached altitudes of 16 to 17,000 feet. The crater is now approximately 1500 feet wide and 300 feet deep. Seismometers recorded 6 earthquakes equal to or larger than magnitude 4.0, including one of magnitude 4.6. Two bursts of harmonic tremor were also recorded.
Governor Dixie Lee Ray declared a State of Emergency and set up a "Mount St. Helens Watch Group." Local officials in Oregon and Washington issued pamphlets prepared by the Federal Emergency Management Agency on "What to do during a volcano ash fall."
Tourists continue to flock to Mount St. Helens. Milepost 33 on State Route 504 has turned into a popular area with volcano watchers. According to a report in The Oregonian, a Weyerhaeuser logging supervisor said his employees were just as curious as the tourists,"...our attendance record (on the job) has been better than ever since the mountain blew. They may be nervous, but this way they can come and gawk." According to later reports in several local newspapers, a Skykomish, WA, man apparently evaded roadblocks and reached the summit of St. Helens on foot. The FAA reported 109 planes inside the restricted zone.
April 4 - Explosions continued with some plumes reaching altitudes of 16,000 feet. Two more episodes of harmonic tremor and 5 earthquakes with magnitudes larger than 4.0 were recorded. Approximately two to three earthquakes of magnitude 3 or 4 were recorded each hour. USGS hydrologist David Frank set up a time-lapse camera at a location 8.4 miles northwest of the volcano. The site overlooks the North Fork Toutle River and has an unobstructed view of St. Helens. It is considered to be high enough to provide safety from even the largest expected mudflow. Additional instruments are slated to be installed over the next few days. The scientists refer to the observation post as "Coldwater" (later referred to as "Coldwater I," following the establishment of a second observation post 4 miles north of the crater called "Coldwater II"). Scientists considered the greatest hazards from an eruption to be flash floods or mudflows, particularly those that might cause Swift Reservoir to overflow.
Washington State Department of Transportation established a volcano viewing area near Ridgefield off of Interstate 5 and made plans to secure another viewing site near Centralia-Chehalis. State officials moved the roadblock on State Route 504 about 20 miles further from the volcano. The roadblock at milepost 34 remained in place, but was unmanned. Officials also considered changes to the roadblock on State Route 503 near Cougar. Governor Dixie Lee Ray called out the National Guard to assist deputies at roadblocks. According to articles in the Vancouver Columbian, overtime for Skamania County law enforcement maintenance of roadblocks ran $6,000 (out of an annual budget of $11,000) for the three days following the first explosions. Loggers met with scientists and public officials in Vancouver to push for more access to restricted areas. According to a Vancouver Columbian article, one company claimed that 50% of their workers have been laid off and operations reduced by 80% due to closures.
April 5 - At least three explosions sent ash to about 15,000 feet. Low concentrations of sulphur dioxide were detected in erupted plumes. Four earthquakes of magnitude 4.0 or larger were recorded. At 6:00 a.m. sixty Washington National Guard troops took up positions at roadblocks. Closures on State Routes 503 and 504 were moved further away from the mountain to provide better control and place the most congested viewing areas off limits. The roadblock on 503 east of Cougar was moved to the junction of the old Lewis River Road (near Jack's Sporting Goods), effectively cutting off tourist traffic to the town.
April 6 - A few insignificant explosions occurred under clouds and rain. Earthquake activity remained about the same as the past few days. There were 54 earthquakes with magnitudes greater than 3.0 recorded, including 6 with magnitudes greater than 4.0. No harmonic tremor was recorded.
April 7 - The crater's dimensions measured approximately 1700 feet long by 1200 feet wide and 500 feet deep. Scientists obtained their first clear view of the vent at the bottom of the deepest part of the crater. A single circular "throat" about 20 feet in diameter was visible. They also reported the first observations of substantial ponding of water. Two pools of muddy water large enough to float chunks of ice disappeared with each explosion then returned as more water accumulated after the explosion subsided. The overall seismicity remained about the same and harmonic tremor was recorded for the first time in two days. Earthquakes were centred beneath the North Slope at depths ranging from one half to three miles. USGS scientists installed a new tiltmeter at the Timberline Viewpoint.
April 8 - At 8:22 a.m. a series of explosions were sighted which lasted at least four hours. It was the longest uninterrupted sequence of explosions to date. During the explosions part of the upper Wishbone Glacier caved into the crater, widening the rim by more than 300 feet. There were 38 earthquakes with magnitudes greater than 3.0, including 4 with magnitudes larger than 4.0. Scientists were uncertain about what the volcano would do next. Most preferred to withhold judgement until more data were available. The National Oceanographic and Atmospheric Association (NOAA) began a weeklong study to compare the emissions from St. Helens to those of industrial sources. Officials moved the roadblock on State Route 503 from Jack's Store back to the Swift Canal east of Cougar after local merchants threatened to sue them over loss of business. The superintendent of the Toutle Lake School District announced evacuation plans for schools in the event of a large eruption of Mount St. Helens.
April 9 - Clouds obscured the mountain, but light ash falls accompanied by the odour of sulphur were reported near Timberline and Spirit Lake from at least three separate explosions. Seismometers recorded 37 earthquakes larger than magnitude 3.0, including 6 larger than magnitude 4.0. A new tiltmeter at Timberline began sending continuous data to Vancouver. The USFS officially designated Mount St. Helens a "geologic area," which protected the forest around the mountain from future land use changes. Geologists reported melting at the base of the Wishbone Glacier. They expressed concerns that continued melting could cause the glacier to slip down into the North Fork Toutle River. Business and traffic returned to Cougar following the relocation of the 503 roadblocks. Fire district officials renewed concerns that tourist traffic may create problems should an evacuation be needed.
April 10 - Weather cleared to permit aerial observations of continued explosions from a circular vent about 30 feet across in the western part of the crater. Harmonic tremor was detected for the first time in three days. Steve Malone of the University of Washington reported that there had been 101 earthquakes with magnitudes larger than 4.0 since March 27.
The Cost of an Eruption - Explosions and earthquakes had settled into a monotonous pattern with no end in site. Mounting expenses began to affect the level of monitoring and maintenance of roadblocks. Since March 20 the USFS estimated expenditures at $157,000. Skamania and Cowlitz Counties had spent $17,000 and $10,000, respectively, for their part in maintaining the roadblocks leading to the mountain. The National Guard estimated costs of $3,800 per day since April 5 for their part in staffing roadblocks. Washington State Patrol spent over $5,000 for their part of this effort. In order to reduce costs, the USFS grounded both observer planes, but kept one on standby in the event of an eruption. They also closed the press centre at the Shilo Inn, ending twice daily briefings. Days before the USGS had reduced the number of scientists monitoring the volcano from 30 to between 5 and 10.
April 11 - A moderate sized explosion was observed in the morning hours. Two new steam vents were noted on the northwest flank just below the crater rim. Ponded water was also visible on the crater floor. A magnitude 4.9 earthquake was recorded in the afternoon, and along with the one on March 28 is the strongest to date. Tiltmeters on the north and east flanks show swelling and subsidence over minutes to hours, but the net changes are inconclusive. Washington State Department of Transportation posted signs for four safe viewpoints along Interstate 5. They were located near exit 14 (Ridgefield Junction), exit 63 south of Toledo, exit 76 south of Chehalis, and the Yale boat launch.
April 12 - Instruments detected ground swelling near Goat Rocks. Scientists who worked in the area reported seeing new ground cracks. The progressive cracking and shifting of the ice on the north side below the crater caused increased concern that a large mass of ice and rock could avalanche into the North Fork Toutle River. A 27-minute episode of harmonic tremor recorded in the afternoon ended with a magnitude 4.5 earthquake. This would be the last episode of harmonic tremor recorded for nearly one month. Aerial photos were taken to compare with previous photos to document changes of the volcano. William Menard, director of the USGS, arrived in Vancouver to observe the volcano and inspect the instrument and data collection activities. Members of the Lower Columbia Amateur Radio Association set up stations on the Toutle River, the Yale School, state department of emergency services headquarters in Olympia, and at the emergency services offices in Kelso as the main line of communications for state emergency services.
April 13 - Eighteen explosions of steam and ash were documented during daylight hours. The number of earthquakes larger than magnitude 4.0 increased to 9, the highest number since March 29. A tiltmeter at Timberline showed small but consistent changes indicating subsidence of the central part of the volcano. USGS scientists installed an additional tiltmeter at East Dome at the foot of the Ape Glacier. Clear weather brought record numbers of sightseers. At 6:30 AM three climbers were spotted near the summit. According to an article in the Longview Daily News the trio climbed the peak in defiance of closure orders to film potential beer commercials. KING TV and KIRO TV from Seattle landed camera crews on the summit later in the day. Although FAA was aware of their entry into restricted airspace, the unauthorized landings were initially thought to have violated the USFS closure of the mountain above tree line. Because Burlington Northern owned the summit, however, the USFS had no jurisdiction over that part of the volcano.
April 14 - Cloudy weather prevented observations. No new ash fall was reported. Seismometers show continued sizeable earthquakes, but no explosions. The Timberline tiltmeter showed continued slight subsidence of the central part of the cone.
April 15 - Only one explosion was documented. The volcano became visible by midday. No changes in ground tilt were recorded. Washington Department of Fish and Game announced that Merrill Lake, Spirit Lake and Swift Reservoir would remain closed to fishing to reduce the temptation of the public to evade roadblocks. The FAA began investigating 7 aircraft that violated restricted airspace around Mount St. Helens. Pilots faced losing their license and fines up to $1000. Skamania County announced the removal of their manned roadblocks on the Lewis River Road and N73. According to a Daily News article, the county cited expense, public harassment, the stable pattern of explosions at the volcano, and the impracticality of keeping people out of the network of logging roads as snow melts. Many National Guard troops have also left. Ten continue to man the roadblock on State Route 504.
April 16 - Nine small steam explosions and some ash fall reported during the day. Seismic activity reached the lowest point for April, with 30 earthquakes of magnitude 3.0 or larger and 3 of magnitude 4.0 or larger. Tiltmeters continue to show no changes. A project to collect ash samples (started on April 14) in snow at 30 stations was completed. Burlington Northern asked the USFS to administer their property on the summit as closed. Television crews who had landed there days before were immune to prosecution because they landed on property that was outside of the closure enforced by the USFS.
April 17 - Twelve small plumes erupted from the crater between 7:00 AM and 1:30 PM. Earthquake activity remained low even though there were two of magnitudes 4.6 recorded. Scientists used the calm to conduct gravity surveys around the mountain, place-surveying targets near the summit, and to estimate the total amount of ash accumulated. Due to continued ground vibrations from earthquakes, fracturing of ice and rocks, subsidence of the summit graben, and accelerated melting of snow and ice, scientists concluded that there was an increased possibility of a large avalanche on the north flank.
April 18 - Steam plumes only rose to about 500 feet above the crater and seismicity remained moderate. As the volcano settled into a "holding pattern" the USGS went from daily information releases to twice weekly. The roadblock on State Route 504 was moved to milepost 19 near the State DOT Kid Valley Maintenance Shed and remained staffed by the Washington State Patrol.
April 19 - Local scientists familiar with the volcano recognized that the upper north flank of the volcano was moving outward, but disagreed on why. Some thought the summit graben subsidence was to blame, others magmatic inflation pushing from within the volcano. There were 37 earthquakes larger than magnitude 3.0 recorded, including 8 larger than magnitude 4.0. No harmonic tremor has been recorded during the last week. US Soil Conservation Service snow samplers found that snow melted faster where covered with a thin layer of ash. USGS hydrologists have not documented any unusual changes in stream levels.
April 20 - No explosions occurred, but seismicity reached the highest point in two weeks. The record showed 47 earthquakes larger than magnitude 3.0, including 7 larger than magnitude 4.0. Fishing season opened, doubtlessly contributing to the number of sightseers who jammed roads leading to the mountain.
April 21 - Poor visibility prevented direct observations of the volcano. The lull continued, with seismicity returning to levels similar to those of the previous week.
April 22 - Improved weather made aerial observations possible. New snow was dusted with ash in only one place. Small bursts of steam around noon were the only activity observed. Other steam vents were visible on the eastern part of the summit area. Tiltmeters continued to record changes that were inconclusive. Forty-two earthquakes larger than magnitude 3.0, including 5 larger than magnitude 4.0, were recorded. In a Columbian article, USGS scientist Dwight Crandell warned those using cabins in the Northwoods area south of the volcano to have an evacuation plan and route ready.
April 23 - No explosions were large enough to add to the light coating of ash seen on fresh snow on the 22nd. Two new steam vents were observed in the crater. There were 38 earthquakes larger than magnitude 3.0 recorded, including 11 larger than magnitude 4.0. Tiltmeters at Timberline and Spirit Lake showed a slight tilting downward to the northwest. Tilt on the south side was downward to the southwest. The overall pattern suggested the volcano might be inflating due to increased magma pressure from below. Gas samples were collected from the steaming areas near the summit. Analysed later, they would be found to contain high concentrations of sulphur dioxide. Data became available from a comparison of aerial photographs taken April 12 with those taken in 1979. From the comparison it appeared some places on the volcano 250 feet higher than 1979. Due to continued quiet, USFS officials scheduled discussions on opening some areas around the volcano to restricted use. USGS scientist Dwight Crandell warned, however, that avalanches from the unstable bulge could cause floods by suddenly raising the level of Spirit Lake or temporarily damming the North Fork Toutle River. In response to demands for more frequent information, USGS scientists resumed daily information releases.
April 24 - Fumaroles continued to steam near the summit crater, but no explosions were large enough to throw material outside of the crater walls. The number of earthquakes recorded has been about the same as in previous days, but average magnitudes are higher. There were 9 earthquakes larger than magnitude 4.0, including one of magnitude 4.7. A total of 38 earthquakes larger than magnitude 3.0 were recorded. USGS Volcano Hazards Project staff released a map showing the possible dangers presented by the bulge area and emphasized the potential for avalanches. The Longview Daily News quoted Dave Johnston on the bulge, " It would seem to indicate something is pushing up from beneath. The obvious speculation is that it might be magma. A major deformation like this is pretty extreme." In the same article they reported that the Red Cross took national disaster workers off standby alert and asked Cowlitz County to return all extra shelter equipment borrowed from division headquarters in Portland.
April 25 - Fumaroles continued to steam and seismic activity continued at about the same level as in previous days. There have been approximately 1560 earthquakes larger than magnitude 3.0, including more than 200 larger than magnitude 4.0, recorded since March 20. USGS scientists conducted an EDM survey to 5 targets on the upper slope of the volcano as well as two additional reference points. Additional survey targets were installed to help define the size, shape and growth of the bulge. At the daily press briefing USGS scientist Dwight Crandell described the Forsythe Glacier as "humped up into one big black rock mass" 300 feet higher than before March 27. A large earthquake or steam blast could send the 150 foot thick mass of ice rushing down the mountain at speeds up to 180 miles per hour. At that speed it would reach Spirit Lake in two minutes. "There will be no way to warn people. If they are in the path, they won't be able to get out of the way." The Spirit Lake highway (State Route 504) would be blocked by the avalanche debris.
April 26 - Steam and ash failed to rise above the crater rim. The tiltmeter at Timberline showed downward tilt to the north, but data from tiltmeters on the south and east flanks did not provide much useful information. The Gifford Pinchot National Forest announced plans to set up tourist information centres at sites with a view of the mountain. Weyerhaeuser considered blocking active logging roads to keep tourists out during the summer. They cited concerns over potential problems with congestion, fires, and accidents with logging trucks.
April 27 - The volcano remained quiet, but fumaroles continued to emit steam. The Timberline tiltmeter showed increased downward tilt to the north. EDM measurements to targets on Goat Rocks dome showed a northward displacement of 15 to 20 feet over the past four days and new cracks were visible in the area of the bulge.
April 28 - Poor visibility hampered visual observations. No signs of explosion debris were noticed beyond the crater. When visible, the crater continued to emit small puffs of steam and ash. The Timberline tiltmeter data suggested continued deformation of the north flank. According to a Longview Daily News article, USGS geologist Dave Johnston said the precise laser surveys revealed that the bulge is not confined to the Forsythe Glacier, but also included Goat Rocks dome. "It's very dramatic to see this much ground motion. It is unusual in a volcano and demands explanation. It can't be anything but some type of dramatic change going on inside the mountain." He added that even if the volcano quieted down, an extreme danger would persist until the north flank stabilized. The "only way it can stabilize is to come down."
April 29 - Further studies of aerial photographs revealed that the bulge was about one mile long and one half mile wide. Ground surveys confirmed that between April 27 and 29 Goat Rocks dome shifted about 9 feet to the northwest. The Timberline tiltmeter continued to show downward tilt to the north, suggesting the bulge extended that far north. Scientists believed the bulge represented the most serious potential hazard. The most serious concerns were about the likelihood of an avalanche into the North Fork Toutle River and Spirit Lake. An avalanche of snow, ice, and rock from the high part of the volcano could move down slope at more than 100 miles per hour.
Emergency services officials are frustrated because the public appeared to remain unaware of the danger. One official was quoted in the Seattle Post-Intelligencer as saying: "The mountain looks so serene, so people can't fathom 4,000 vertical feet of earth, rock and ice plunging into (Spirit Lake) in less than two minutes."
State officials asked the governor to close a large area around the volcano. The plan called for a Red Zone (no public access) and a Blue Zone (restricted access).
April 30 - The volcano remained quiet, but the bulge continued to expand northward. Only 15 earthquakes larger than magnitude 3.0 were recorded, including 6 larger than magnitude 4.0. During the quiet, USGS geologist Dave Johnston sampled water from a small pond that had formed in the crater bottom. Concerned with the increasing instability of the bulge, USGS scientists issued an updated Hazards Warning. Governor Ray and Forest Supervisor Robert Tokarczyk closed additional areas near the volcano based on this information. A Red Zone was established who’s boundary ranged from 3 to 7 miles out from the peak. Access in this zone was restricted to scientists, law enforcement, and other officials. A Blue Zone was established. Access into this area was restricted during daylight hours to loggers and property owners with special permits.
May 1 - The mountain continued to steam continuously without explosions. A small pool of water persisted in the crater. One survey target reportedly moved outward two feet in less than 12 hours. There were 26 earthquakes larger than magnitude 3.0, including 5 larger than 4.0. A new seismic station was installed on Dogs Head to help detect earthquakes that might trigger a major avalanche and to improve the accuracy of earthquake location. The USGS established a new observation post about 5 miles north of the summit. Dubbed "Coldwater II", the site housed time-lapse cameras and monitoring equipment from the previous site at Coldwater. A travel trailer has been placed on site to provide shelter for observers who are now located there around the clock.
According to the Longview Daily News two new gates were placed on State Route 504, one at Camp Baker and one at the Skamania County line. The paper also reported that although Cougar was inside the Blue Zone, residents had not yet been asked to evacuate. Also according to the same issue, at least three cabin owners in the Spirit Lake area refused to pay their annual property taxes because they were not allowed access to their property.
May 2 - No explosions were reported. There were 30 earthquakes larger than magnitude 3.0, including 8 larger than 4.0. Five of these occurred within a twenty-minute period, waking residents of Toutle. To date there have been 2,395 earthquakes larger than magnitude 3.0 recorded, including 258 larger than 4.0. Thermal infrared surveys made by personnel from the US Naval Air Station at Whidbey Island revealed a previously unknown area of warm rock in the middle of the bulge. Ice continued to break up in this area, which was about 100 feet long and 50 feet wide.
Skamania County Sheriff Bill Closner accused television newsmen of practicing "one-upsmanship" by continuing to fly helicopters into the Red Zone. USFS spokesman Jim Unterwegner expressed concern that people did not seem to take the danger seriously: “One of the problems we're having...is that people in the Northwest have never faced this kind of thing before...I feel the general public really doesn't understand the danger." He referred to a man who recently telephoned to request a permit to climb the mountain. The man wanted to lodge a complaint when the permit was denied. According to the Longview Daily News, Spirit Lake cabin owners became eligible for federally funded flood insurance. The insurance would not cover homes crushed by an avalanche, however.
May 3 - The mountain continued to steam without explosions and the bulge continued to grow. Only 26 earthquakes larger than 3.0 were recorded, including 5 larger than 3.9. The USGS took time from monitoring efforts to discuss funding for the increasingly expensive volcano watch.
May 4 - The volcano remained quiet. The bulge continued to move outwards by as much as 5 feet per day in places. USGS geologists were convinced that some bulging resulted from intrusion of magma in late March, but were uncertain if the current bulging is due to intrusion or settling of the already displaced part of the mountain. COSPEC measurements made from Timberline did not detect significant amounts of sulphur dioxide.
May 5 - Strong emissions of ash have been uncommon for the past three weeks. The Goat Rocks EDM target had moved outwards to the north between 40 and 50 feet over the previous 11 days. During an interview with the Tacoma News Tribune Jack Hyde, a Tacoma Community College geologist speculated that the instability of the bulge might result in a massive landslide. A spectacular explosion of lava, possibly without warning, could follow the landslide as vents on the northern slope are opened up. USGS geologist Bob Tilling was quoted in The Oregonian: "(The deformation) is continuing at a very high rate. Sometime it has to go. We just don't know how much longer this can last." In the meantime, smoke from slash burns prompted rumours of lava flows.
One of the reasons some people do not understand why scientists and officials have remained cautious may be their familiarity with famous Hawaiian volcanoes. Their frequent eruptions and familiar lava flows have contributed to the popular belief that all volcanoes have fluid, channelized lava flows. One logger was quoted: "We're logging 10 miles away from the peak...I don't see any hazard. I just came back from Hawaii, where they run tourist buses right up to the edge of a venting volcano."
May 6 - Clouds obscured the mountain. There were no documented explosions. Earthquake activity continued at about the same level as during previous weeks. The bulge continued to push outwards at 4 to 5 feet per day. For the past two weeks the mountain has done nothing to convince a non-scientist that a volcanic hazard exists. In a Vancouver Columbian article the Sierra Club was quoted as suggesting that Mount St. Helens be considered for national monument status.
May 7 - Explosions resumed after a two-week break. Steam and ash plumes reached 13,000 feet. The bulge continued to push outwards. Earthquake activity remained about the same. Since March 20 2550 earthquakes larger than magnitude 3.0 have been recorded, including 291 larger than 4.0. According to a USFS spokesman, “we’ve had more quakes above 4.0 here in the past few weeks than California has had in the past ten years." Due to renewed activity, USGS geologist Don Mullineaux cancelled a town meeting in Toutle. The meeting was planned to address concerns of local residents about the ongoing crisis.
May 8 - Muddy rain fell on Timberline as ash was carried to the north and east of the mountain. Steam was observed in the crater and near the head of Shoestring Glacier. At noon airborne observers noted many new avalanches up to 100 feet wide and 1000 feet long on the Wishbone Glacier. There were 25 earthquakes larger than magnitude 3.0 recorded, including 11 larger than 4.0. This was the highest number of large earthquakes since April 24. Harmonic tremor was also recorded, the first since April 12.
May 9 - Explosions continued. Continuous steaming in the crater and at the head of Shoestring Glacier was observed. There were 21 earthquakes larger than magnitude 3.0 recorded, including 9 larger than 4.0. The largest reached magnitude 4.9. The USGS ceased measurements at the Timberline Viewpoint due to the increased danger from sudden avalanches. USGS seismologist Craig Weaver said the new seismic station at Dogs Head may give notice of a massive landslide and will allow scientists to monitor steam and ash emissions 24 hours a day, regardless of weather. USGS geologist Don Mullineaux told at least 130 Toutle residents that the risks from Mount St. Helens were something they could live with. He pointed out that the school where the crowd had gathered was one of the safest places in the area at 135 feet above the valley floor.
May 10 - The volcano remained under clouds most of the day. Steam and ash emissions were visible once the weather cleared. Surveys of the bulge showed that the outward motion had slowed to less than 3 feet per day, about half the average rate for the previous two weeks. The low rate was later considered to be the result of an erroneous measurement. There were 20 earthquakes larger than magnitude 3.0 recorded, including 10 larger than 4.0.
Professor Al Eggers of the University of Puget Sound told reporters that tide-producing gravitational forces would be exceptionally strong on May 21. He warned that the extreme force might trigger an eruption if the volcano were already set to erupt. Although most USGS scientists did not totally discount the idea, many believed other factors such as magmatic pressure inside the mountain were likely more important.
May 11 - Small bursts of steam and ash were emitted. There were 24 earthquakes larger than magnitude 3.0 recorded, including 10 larger than 4.0. Increased steaming was observed at the upper Shoestring Glacier fumaroles. Most USGS and UW scientists believe any major eruption would be preceded by a change in the seismic activity or rate of bulging. If the patterns do not change before the onset of a major event - such as the expected massive avalanche - they may be unable to provide advance warning.
May 12 - Small explosions continued. Observers noted a cluster of fumaroles on the western rim of the crater. There were 28 earthquakes larger than magnitude 3.0 recorded, including 8 larger than 4.0. A magnitude 5.0 earthquake triggered an 800 foot wide avalanche down the north flank. Scientists believed this avalanche demonstrated the increased instability of the north flank and a sample of larger events to come. UW seismologists moved a portable seismic recorder from Spirit Lake to a ridgetop northeast of the volcano. The instrument could have been destroyed if an avalanche reached Spirit Lake.
May 13 - Steam and ash explosions decreased in frequency. Most ash fell near the crater. Steam emission increased from the Shoestring fumaroles. A false report that a large eruption had sent ash to 18,000 feet prompted FAA officials to issue a pilot's warning that an ash plume extended 20 miles to the north-northeast and was "of extreme hazard to aircraft."
May 14 - Poor weather obscured the volcano for half the day. A new steam vent was visible between the two small peaks on the northern crater rim. The north flank continued to bulge outwards at about 5 feet per day. Seismicity remained at about the same or slightly lower level than in previous days. Scientists from Dartmouth reported measurements of sulphur dioxide at 10 to 20 tons per day during explosions and about 1 ton per day between explosions. A crank phone call reporting flowing lava was placed to KING TV in Seattle. Within minutes rumours of the lava had reached Portland and Vancouver. According to USGS scientist Bob Decker, "it was a rumour spread by people trying to confirm a rumour."
May 15 - Explosions ceased, but new ash was visible on the south-western flank. Some summit vents appeared to be filled with fallen blocks of ice. The bulge continued to push outward at about 5 feet per day. Seismic activity included an earthquake of magnitude 4.8. Fifty days have passed since the first explosion (March 27), yet there has been no sign of fresh magma in the ash.
Continued activity has attracted tourists from around the world. Many congregated at roadblocks for picnicking, socializing, or waiting for the clouds to clear. Three workers were flown in to evacuate equipment from the YMCA and Boy Scout camps on Spirit Lake.
May 16 - No explosions were reported. There were 28 earthquakes larger than magnitude 3.0 recorded, including 10 larger than 4.0. There have been no records of harmonic tremor since May 8. Steam continued to emanate from the summit area. Portions of the upper reaches of the bulging north flank were also steaming. The shape of the volcano has changed considerably during the past 10 days. The north and northwest rims of the crater have abundant cracks that are partially filled with snow and ash. The area appears to be moving downward as a mass toward the crater. The bulge continued to appear highly broken and distorted.
Before dawn Department of Energy personnel made an aerial infrared survey. The data were not immediately available for interpretation. Glaciologists placed a time-lapse camera on Dogs Head aimed at the growing bulge.
Owners of private property in the Red Zone demanded access to homes and cabins they were forced to leave weeks ago. Some threatened to converge on the roadblocks in numbers and go through "come hell or high water." The National Weather Service predicted good weather for volcano watching for the coming weekend.
May 17 - The mountain remained quiet. Seismic activity reached the lowest level for May, with only 18 earthquakes larger than 3.0 recorded (including 6 larger than magnitude 4.0). In response to pressure from property owners and with the Governor's consent, law enforcement officials escorted about 50 carloads of property owners into the Red Zone to retrieve possessions. Those who entered were required to sign liability waivers at the roadblocks and to leave by nightfall. Authorities agreed to allow another caravan of property owners in at 10:00 a.m. the following morning.