GEOLOGY

Detailed explanation-1: -It is known for having phreatomagmatic eruptions in which the interaction of magma and water cause explosive eruptions that eject steam, ash, volcanic rock fragments, and incandescent bombs.

Detailed explanation-2: -A good example is the eruption of Washington’s Mount St. Helens. In this type of eruption, the magma blasts into the air and breaks apart into pieces called tephra. Tephra can range in size from tiny particles of ash to house-size boulders.

Detailed explanation-3: -There are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra. Effusive eruptions, meanwhile, are characterized by the outpouring of lava without significant explosive eruption.

Detailed explanation-4: -This style of eruption is named for the eruption of Vesuvius in 79 CE which was witnessed by Pliny the Elder. The May 18, 1980 eruption of Mount St. Helens was Plinian. The 1912 eruption of Novarupta in Katmai National Park and Preserve also was Plinian.

Detailed explanation-5: -There are four types of eruptions with properties determined mostly by the silica content of magma, and the amount of gas it contains. In order of increasing explosiveness, these are Hawai’ian, Strombolian, Vulcanian, and Plinian eruptions.