Operation Fiery Vigil

Operation Fiery Vigil
United States military dependents board USS Abraham Lincoln (CVN-72) in the aftermath of the eruption
Location	Philippines
Objective	Evacuation of American military and civilian personnel from Clark Air Base and U.S. Naval Base Subic Bay
Date	June 1991
Executed by	United States
Outcome	Successful operation

Operation Fiery Vigil was the emergency evacuation of all non-essential military and United States Department of Defense civilian personnel and their dependents from Clark Air Base and U.S. Naval Base Subic Bay during the June 1991 volcanic eruption of Mount Pinatubo in the Philippines. This noncombatant evacuation operation (NEO) resulted in the transfer of roughly 20,000 people from Clark Air Base and U.S. Naval Base Subic Bay back to CONUS, by way of Cebu, Philippines. The Commanding General, 13th USAF, was in command of the Joint Task Force.

The 1991 Plinian/Ultra-Plinian eruption of Mount Pinatubo was the second largest terrestrial eruption of the 20th century (surpassed only by the 1912 eruption of Novarupta), and the largest eruption in living memory. The eruption produced high-speed pyroclastic flows, giant lahars, and a cloud of volcanic ash hundreds of miles across. 20 million tons of sulfur dioxide and roughly 11 cubic kilometers (2.6 cu mi) of tephra are estimated to have been ejected in total, which corresponds to a Volcanic Explosivity Index (VEI) of 6. By contrast, roughly 4 km³ of material was ejected in the 1980 eruption of Mount St. Helens; this corresponds to a VEI of 5.

Very few of the estimated 20,000 who left the base ever returned. The vast majority were evacuated to Andersen Air Force Base, Guam and processed for return to the continental United States. This figure includes approximately 5,000 who were evacuated to Cebu City on the USS Midway (CV-41), USS Abraham Lincoln (CVN-72), USS Peleliu (LHA-5), USS Arkansas (CGN-41), USS Gary (FFG-51) and eighteen other U.S. Navy ships of the task force.