Mount Pinatubo

Mount Pinatubo is a stratovolcano on the island of Luzon in the Philippines, at the border of Zambales, Tarlac and Pampanga provinces, standing about 1,486 meters after having lost roughly 260 meters of its former summit height in its own catastrophic 1991 eruption. Before that eruption Pinatubo had been dormant for around 500 years and was barely recognized as a volcano at all by nearby communities; its June 15, 1991 eruption proved to be the second-largest volcanic eruption of the 20th century, ejecting an enormous volume of ash and sulfur dioxide that formed a stratospheric aerosol veil measurably cooling global average temperatures by roughly half a degree Celsius for about a year afterward, while pyroclastic flows and, compounded by the coincident arrival of Typhoon Yunya, lahars (volcanic mudflows) devastated surrounding areas and forced the permanent closure of the nearby U.S. Clark Air Base. The eruption's toll was sharply reduced from what it might otherwise have been because scientists successfully forecast the event days in advance, prompting large-scale evacuations credited with saving thousands of lives. The volcano's collapsed summit today holds Lake Pinatubo, a crater lake that formed in the aftermath. This entity documents Mount Pinatubo specifically as a geological formation, a Luzon stratovolcano whose 1991 eruption was the century's second-largest and measurably cooled global temperatures.