GEOLOGY

Detailed explanation-1: -Magma contains dissolved gases, which provide the driving force that causes most volcanic eruptions. As magma rises towards the surface and pressure decreases, gases are released from the liquid portion of the magma (melt) and continue to travel upward and are eventually released into the atmosphere.

Detailed explanation-2: -A volcano’s explosiveness depends on the composition of the magma (molten rock) and how readily gas can escape from it. As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions.

Detailed explanation-3: -Gas gives magmas their explosive character, because volume of gas expands as pressure is reduced. The composition of the gases in magma are: Mostly H2O (water vapor) & some CO2 (carbon dioxide) Minor amounts of Sulfur, Chlorine, and Fluorine gases.

Detailed explanation-4: -While heat is what causes magma to rise to the surface, escaping gases provide the driving force for volcanic eruptions. The most common volcanic gas is steam. This is formed when water from within the Earth or rainwater soaking into the ground is absorbed by magma and then heated.

Detailed explanation-5: -The more viscous a fluid, the less easily it flows but the more gas it can trap in solution, making high-silica magma more explosive. In any magma chamber, silica is the primary ingredient, and the amount of silica determines how an eruption will behave.