On May 18th, 1980, thirty years ago today, at 8:32 a.m., the ground shook beneath Mount St. Helens in Washington state as a magnitude 5.1 earthquake struck, setting off one of the largest landslides in recorded history – the entire north slope of the volcano slid away. As the land moved, it exposed the superheated core of the volcano setting off gigantic explosions and eruptions of steam, ash and rock debris. The blast was heard hundreds of miles away, the pressure wave flattened entire forests, the heat melted glaciers and set off destructive mudflows, and 57 people lost their lives. The erupting ash column shot up 80,000 feet into the atmosphere for over 10 hours, depositing ash across Eastern Washington and 10 other states. Collected here are photos of the volcano and its fateful 1980 eruption. [Editor's note: I lived in Eastern Washington at the time, and have strong memories of this event, the dark skies, the strangeness of it all. I can't believe it's been 30 years. -Alan]

source: Boston.com

Ash billows from the crater where the summit of Mount St. Helens had been only hours earlier during a huge eruption on May 18th, 1980. (USGS/Robert Krimmel)

Mount St. Helens in eruption on May 18, 1980 showing the violence of the eruption in contrast with the apparently quiet countryside, Mount Adams in background, right. (USGS photo) #

Ash and steam billow from the crater of Mount St. Helens on May 18, 1980. (USGS photo) #

Mount St. Helens sends a plume of ash, smoke and debris skyward in this May 18, 1980 photo. The ash plume is being carried eastward by prevailing winds, depositing ash across several states. (AP Photo/US Geological Survey) #

A satellite image shows the eastward spread of the ash plume across Washington state from the May 18th, 1980 eruption of Mount St. Helens, approximately one hour after the initial eruption. (NOAA) #

Ashen clouds from the Mount St. Helens volcano move over Ephrata airport in Washington on Monday, May 19, 1980. (AP Photo/Mike Cash) #

A car is shown submerged in ash in this May 20, 1980 photo from Mount St. Helens eruption in Washington State. (AP Photo) #

For weeks volcanic ash covered the landscape around the volcano and for several hundred miles downwind to the east. In this photograph, a helicopter stirs up ash while trying to land in the devastated area on August 22nd, 1980. (USGS/Lyn Topinka) #

A mudflow deposit covers Washington State Highway 504 near the town of Toutle, northwest of Mount St. Helens, to a depth of 2m (6 ft). Geologist for scale. (USGS/R.L. Schuster) #

On the slopes of Mount St. Helens, colorful ponds dot the debris avalanche, their chemical composition varying wildly and affecting the color of the water. Photo taken on August 8, 1981. (USGS/Lyn Topinka) #

In this May 7, 2010 photo, a timed exposure brings out Mount St. Helens against a backdrop of stars and the risen moon at left, in Washington state. (AP Photo/Ted S. Warren) #

source: Boston.com