May 18, 1980 Earthquake: Mt St Helens, Washington, United States

Name: May 18, 1980 Earthquake: Mt St Helens, Washington, United States
Start: 1980-05-18
Location: Mt St Helens, Washington, United States

May 18, 1980 · M5.2 · 61 deaths · $2 billion

A magnitude 5.2 earthquake struck Mt St Helens, Washington, United States on May 18, 1980 at 15:32:11 UTC, 4 km below the surface. It killed 61 people, counting the tsunami it caused.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date: May 18, 1980
Time: 15:32:11 UTC
Place: Mt St Helens, Washington, United States
Magnitude: 5.2 (Ms)
Focal depth: 4 km (2 mi)
Intensity: 5 on the Modified Mercalli scale
Tsunami: Yes: the tsunami it caused
Volcano: The eruption it came with
Epicenter: 46.214° N, 122.194° W
Country: United States

The toll

Deaths: 61 with its tsunami and other effects
Damage: $2 billion with its tsunami and other effects

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.

An earthquake occurred at 15 32 UT, only seconds before the explosion that began the eruption of Mount St. Helens volcano. This eruption and blast blew off the top of the volcano, reducing its elevation by 396 m, killed 31 people and caused an estimated property damage of between $0.5 billion and $2 billion. About 53 earthquakes having magnitude larger than 4.5 were located near Mount St. Helens before the main event and eruption. No earthquakes having magnitudes higher than 4.5 were located following the eruption. (reference #542)

Reference #1066 lists $2000 million damage, 31 deaths.

Reference #1053 lists 32 deaths.

Reference #1412 lists 57 deaths.

Other significant earthquakes nearby

Within 200 km, the deadliest first.

Significant earthquakes of 1980 The 1900s Every quake the USGS located in 1980 Recent earthquakes near here This day in weather history

Sources

Significant earthquakes 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 earthquake 4876.