Mount+St.+Helens,+Washington,+1980+(302)

Materials produced in eruption//** ||= **//Human response (before and after)//** ||= **//No. of casualties/ Main cause of casualty//** ||= **//Terms that might need explanation//** || The rock responded by exploding a hot mix of [|lava] and pulverized older rock A [|volcanic ash] column [|Groundwater] -derived [|steam] [|Sulfur dioxide] emission, [|Explosions] burst through the trailing part of the landslide, blasting rock debris northward. The resulting blast laterally directed the [|pyroclastic flow] of very hot volcanic gases, ash, and [|pumice] formed from new lava, while pulverized old rock hugged the ground  || [|Unemployment] in the immediate region of Mount St. Helens rose tenfold in the weeks immediately following the eruption. Few residents reported suffering [|stress] and [|emotional] problems, even though they had coped successfully during the crisis. Counties in the region requested funding for mental health programs to assist such people || Fifty-seven people were killed and 200 homes, 27 bridges, 15 miles (24 km) of railways and 185 miles (300 km) of highway were destroyed Hundreds of square miles were reduced to wasteland, causing over a billion [|U.S. dollars] in damage Most of the 57 people known to have died in that day's eruption succumbed to [|asphyxiation] while several died from burns More than 4 billion [|board feet] (14.6 km³) of [|timber] was damaged or destroyed, 0. Downwind of the volcano, in areas of thick ash accumulation, many agricultural crops, such as wheat, apples, potatoes, and [|alfalfa], were destroyed. As many as 1,500 [|elk] and 5,000 [|deer] were killed, and an estimated 12 million Chinook and [|Coho] [|salmon] fingerlings died when their hatcheries were destroyed. Another estimated 40,000 young [|salmon] were lost The ash fall created some temporary but major problems with [|transportation], [|sewage] disposal, and [|water treatment] systems. Visibility was greatly decreased during the ash fall, closing many highways and roads. || ** Pyroclastic Flow: ** A **//pyroclastic flow//** is a fluidized mixture of solid to semi-solid fragments and hot, expanding gases that flows down the flank of a volcanic edifice. These awesome features are heavier-than-air emulsions that move much like a snow avalanche, except that they are fiercely hot, contain toxic gases, and move at phenomenal, hurricane-force speeds, often over 100 km/hour. They are the most deadly of all volcanic phenomena.
 * = **//Nature of eruption/
 * The partly molten, gas- and [|steam] -rich [|rock].
 * Avalanche: ** An **avalanche** is a rapid flow of snow down a slope, from either natural triggers or human activity. Typically occurring in mountainous terrain, an avalanche can mix air and water with the descending snow.
 * Landslide: ** A **landslide** (or landslip) is a [|geological phenomenon] which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of [|gravity] is ||