what does magma's viscosity depend on?
The viscosity of magma depends upon its silica content and its what? The viscosity is also dependent on temperature. Higher Temperature results in lower viscosities typically, i.e more runny.
Viscosity is the resistance to flow (opposite of fluidity). Viscosity depends on primarily on the composition of the magma, and temperature. Higher SiO2 (silica) content magmas have higher viscosity than lower SiO2 content magmas (viscosity increases with increasing SiO2 concentration in the magma). Lower temperature magmas have higher viscosity than higher temperature magmas (viscosity decreases with increasing temperature of the magma).