Mount St Helens is located in the Cascade mountain range in the state of Washington in the United States and is famous for its devastating 1980 eruption, which killed 57 people. Among the dead were a geologist and others who were monitoring the volcano. The victims closest to the eruption were killed almost instantly when an earthquake triggered a huge landslide that unleashed a sideways blast that sent clouds of hot gas, ash and rock speeding away from the volcano.
The eruption of Mount St Helens and another volcano in Mexico called El Chichon two years later were the first times that pyroclastic flows – clouds of very hot gas, ash and rock that move at hundreds of miles per hour – were studied using modern scientific techniques.
Mount St Helens remains active and has erupted periodically since 1980.
Image: Mount St Helens erupts in July 1980 (credit: Science Source/USGS/Science Photo Library)
Mount St Helens helped scientists understand these powerful events.
The 1980 eruption of Mount St Helens and El Chichon two years later were the first times that pyroclastic flows were studied using modern scientific methods, as volcanologist Haraldur Sigurdsson explains in this clip. These devastating flows of hot ash and rock speed down the slopes of volcanoes destroying everything in their path.
Iain Stewart tells the story of Mount St Helens' 1980 eruption.
Professor Iain Stewart tells the story of Mount St Helens' 1980 eruption. An earthquake-triggered landslide unleashed a sideways blast of hot gas and ash from this famous stratovolcano volcano (also known as a composite volcano) in the state of Washington, USA.
In 2004 earthquakes suggest an eruption is imminent.
In this 2004 report, the BBC's Ian Pannell spoke to experts who warned that Mount St Helens was showing the warning signs of an eruption. After a period of volcanic activity that lasted until 2008, the volcano quietened down and no major eruption occurred.