GEOLOGY

Detailed explanation-1: -Magmas that have a high silica content will therefore exhibit greater degrees of polymerization, and have higher viscosities, than those with low-silica contents. The amount of dissolved gases in the magma can also affect it’s viscosity, but in a more ambiguous way than temperature and silica content.

Detailed explanation-2: -A magma’s silica content will not only control the rock type that forms, it also controls the relative viscosity of the magma. Differences in a magma’s viscosity will determine the shape a volcano takes. High-silica (basalt) magma has a much lower viscosity. It flows much easier and over longer distances.

Detailed explanation-3: -The composition of magma determines its viscosity, which affects how a lava flows and what kind of volcano forms from the lava.

Detailed explanation-4: -Rhyolitic magmas tend to have even higher viscosity, ranging between 1 million and 100 million times more viscous than water.

Detailed explanation-5: -How does the composition of magma determine an eruption’s characteristics? Silica content determines viscosity, and the amount of dissolved gases help determine explosivity. How is the viscosity of magma related to its explosivity? The more viscous the magma, the more explosive the eruption.