GEOLOGY

Detailed explanation-1: -Because it is more difficult for dissolved gas to escape from more viscous magma, higher silica magmas generally erupt more explosively.

Detailed explanation-2: -As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions. Magmas with high silica content tend to erupt violently, because they are viscious.

Detailed explanation-3: -Silica-rich magma is highly explosive because the gases within the magma build up within the highly viscous magma and burst when pressure is too great. Viscosity is defined as the stickiness or thickness of a liquid when flowing, and silica can create this stickiness within magma.

Detailed explanation-4: -Volcanoes with silica-rich and highly viscous magma tend to produce violent explosive eruptions that result in disasters in local communities and that strongly affect the global environment.