GEOLOGY

Detailed explanation-1: -A phreatic eruption is made up of steam-driven explosions that occur when water beneath the ground or on the surface is heated by volcanic activity. The water, once heated, begins to boil or can even flash straight to steam, causing an explosion.

Detailed explanation-2: -Phreatomagmatic Eruptions. Phreatomagmatic eruptions are eruptions that arise from interactions between water and magma. They are driven from thermal contraction (as opposed to magmatic eruptions, which are driven by thermal expansion) of magma when it comes in contact with water.

Detailed explanation-3: -A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water.

Detailed explanation-4: -Phreatic eruption at the summit of Mount St. Helens, Washington. Hundreds of these steam-driven explosive eruptions occurred as magma steadily rose into the cone and boiled groundwater.