MOUNT ST HELENS

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 thevolcano. 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)