GEOLOGY

Detailed explanation-1: -Phreatic and Phreatomagmatic Eruptions When this happens, the water is instantly turned to steam in a reaction known as “flashing.” The steam explodes from the ground, shattering the rock surrounding it and throwing those rocks around, but none of the magma gets out.

Detailed explanation-2: -Magmas can vary widely in composition, but in general they are made up of only eight elements; in order of importance: oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, and potassium (Figure 3.2.

Detailed explanation-3: -Magma compositions vary, but will have eight main elements in different proportions. The most abundant elements are oxygen and silicon, followed by aluminum, iron, calcium, sodium, magnesium, and potassium. These eight elements are also the most abundant in Earth’s crust (Figure 7.2).

Detailed explanation-4: -The distinction between magma and lava is all about location. When geologists refer to magma, they’re talking about molten rock that’s still trapped underground. If this molten rock makes it to the surface and keeps flowing like a liquid, it’s called lava.