Viscosity of magma, the resistance to flow depends on composition of the magma and temperature. Higher silica content means higher viscosity. But lower temperatures and low gas content mean higher viscosity. Hence, lower viscosity and low gas content mean higher temperature of magma.

Different minerals within a rock melt at different temperatures. The amount of partial melting and the composition of the original rock determine the composition of the magma. The higher the amount of silica in the magma, the higher is its viscosity. Viscosity is a liquid’s resistance to flow.

Both the temperature and mineral content of magma affect how easily it flows. The viscosity (thickness) of the magma that erupts from a volcano affects the shape of the volcano. Volcanoes with steep slopes tend to form from very viscous magma, while flatter volcanoes form from magma that flows easily.

Viscosity depends on primarily on the composition of the magma, and temperature. This property is increased by crystallization of magma while temperature decreases. Finally, the composition of a magma highly affects its viscosity. A higher concentration in silica leads to a more acid/more viscous magma.

The chemical composition of magma can vary depending on the rock that initially melts (the source rock), and process that occur during partial melting and transport. The initial composition of the magma is dictated by the composition of the source rock and the degree of partial melting.

Main Vent: A volcano’s main vent is the weak point in the Earth’s crust where hot magma has been able to rise from the magma chamber and reach the surface.

80 percent

The temperature of the inner core is far above the melting point of iron. However, unlike the outer core, the inner core is not liquid or even molten. The inner core’s intense pressure—the entire rest of the planet and its atmosphere—prevents the iron from melting.