become active and spew forth lava and rocks; "Vesuvius erupts once in a while"

geology: cause molten material, such as lava, to pour forth

To force or let out of the proper vessels or arteries, as blood.

To pass by infiltration or effusion from the normal channel, such as a blood vessel or a lymphatic, into the surrounding tissue; -- said of blood, lymph, etc.

To leak outside of a blood vessel