1.what triggers the small earthquakes that occur before a volcanic eruption a. upward movement of a magma
b. pyroclastic flow
c. cooling magma inside the crush
d. plate movements
2.what causes magma to erupt towards the earths surface
a. the density in the magma
b. dissolved gasses trapped in the magma
c. gravity of the lithosphere
d. the silica in the magma
3.this happens when temperature of lava increased
a. the viscosity increases
b. the viscosity decreases
c. can flow on short distances
d. begins to harden