Tsunamis in 1980

May 18, 1980 Tsunami: Washington, United States

May 18, 1980 · 250 m · 61 deaths · Definite tsunami

A tsunami caused by a volcano and a landslide began at Washington, United States on May 18, 1980. The water rose as high as 250 meters. Its effects were recorded at 2 places. It killed 61 people, counting the earthquake or eruption that caused it.

Where the waves reached

The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.

  • Under 1 m
  • 1 to 3 m
  • 3 to 10 m
  • 10 to 30 m
  • 30 m and more
  • Height not recorded

Tsunami warnings in force

The tsunami

Date
May 18, 1980
Source
Washington, United States
Cause
Volcano and landslide
Earthquake
The earthquake
Maximum water height
250 m (820.2 ft)
Runups recorded
2
Waters
A lake or river, not the ocean
How certain
Definite tsunami
Source location
46.200° N, 122.180° W

The toll

Deaths
61 with the earthquake or eruption that caused it

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

What the record says

NCEI’s account, from the sources it cites.

On 18 May 1980 the upper 1500 ft (460 m) including the former summit of Mount St. Helens suddenly detached as a gigantic landslide (debris avalanche). The great avalanche slipped off the volcano and slammed into Spirit Lake, raising the lake surface by 63 m (207 ft) and sending a cataclysmic tsunami surging around the lake basin as high as 250 m (820 ft) above the old lake level.

(above from reference #2596)

Every runup

Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.

WhereCountryKm from sourceWater height, mInland, mMeasured byFirst wave, UTCDeaths
Spirit Lake West, WA, WAUnited States9250Eyewitness observation of water height
Spirit Lake East, WA, WAUnited States10225Eyewitness observation of water height

Photos

From the NCEI/WDS Natural Hazards Image Database (doi:10.7289/V5154F01). Only photos by the USGS and NOAA, which are public domain, are shown.

Steam Eruption at Mount Saint Helens, WA, Prior to May 18, 1980 Eruption
Steam Eruption at Mount Saint Helens, WA, Prior to May 18, 1980 Eruption A typical phreatic (steam) eruption in early May. Note the increased size of the vent. Eruptive activity increased greatly about May 7, following a two week quiet period. Steam and ash eruptions reached elevations of 13,000 feet during this period. There were also steam eruptions at several sites on the north flank. Photo: D. Wellman, NOAA.
Ash Cloud from Distance of Three Miles, Mount Saint Helens, WA
Ash Cloud from Distance of Three Miles, Mount Saint Helens, WA View of the south face from less than three miles, during the height of the May 18, 1980, eruption. Note that steam as well as ash is billowing from the crater and that larger fragments are beginning to fall from the cloud. Rock fragments and pumice that were carried upward along with the ash rained down in an area that extended 25 to 30 miles to the north… Photo: D. Wellman, NOAA.
Eruption Cloud from Yakima, Washington
Eruption Cloud from Yakima, Washington The eruption cloud as it approaches the Yakima, Washington, airport on May 18, 1980. The ash cloud moved at an average speed of about 60 miles an hour and reached the airport by 9:45 A.M., 75 minutes after the start of the eruption. The cloud became so dense that little sunlight penetrated it. Photo: D. Wellman, NOAA.
Ash Fall at Sand Point, Idaho
Ash Fall at Sand Point, Idaho The ash fall at Sand Point, Idaho, more than 300 miles northeast of Mount Saint Helens. At the height of the ash fall, even at this distance there was not enough daylight to properly expose film. The car has been covered to protect it from the abrasive ash. Ash continued to fall several days after the eruption had subsided. It damaged or destroyed many… Photo: David Schoolcraft, NOAA National Geophysical Data Center.
Snow Plow Removes Volcanic Ash near Coeur D'Alene, ID
Snow Plow Removes Volcanic Ash near Coeur D'Alene, ID Snow plow removing ash from highway near Coeur d'Alene, in northwestern Idaho. More than 185 miles of highways and roads and 15 miles of railways were destroyed or extensively damaged. Many highways and roads were closed to traffic. Driving was discouraged during the ash fall because the ash was harmful to the internal combustion engines. Photo: David Schoolcraft, NOAA National Geophysical Data Center.

More

Every tsunami in 1980The 1900sTsunamis of United StatesThe earthquakeThe eruptionThis day in weather historyAlerts in force

Sources

Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 3018.