The Minoan eruption of Thera, also referred to as the Thera eruption or Santorini eruption, was a major catastrophic volcanic eruption with a Volcanic Explosivity Index (VEI) of 6 or 7 and a dense-rock equivalent (DRE) of 60 km³ (14 cu mi), which is estimated to have occurred in the mid-second millennium BCE. The eruption was one of the largest volcanic events on Earth in recorded history.