What caused the eruption of Mount Vesuvius in 79 A.D.?
The eruption was triggered by a foreboding of a series of violent earthquakes. It also erupted violently because in the 63A.D. eruption,rising lava got hardened in the vent of the volcano which caused all the pressure to build up and then finally explode in a deadly violent eruption of smoke, pumice(a spongy looking rock), and volcanic ash.