In the third stage, Vulcanian eruptions took place at Huaynaputina and deposited another ash layer; it is thinner than the layer produced by the first stage eruption and appears to be partly of phreatomagmatic origin. During this stage the volcano also emitted lava bombs; the total volume of erupted tephra is about . This third stage destroyed the lava dome and formed the third vent, which then began to settle along the faults as the underlying magma was exhausted. The fourth vent formed late during the eruption, outside of the amphitheatre.