Mount Pinatubo produced the 1991 eruption, one of the largest volcanic eruptions of the 20th century.
Before the eruption, Pinatubo was a relatively inconspicuous volcano on Luzon. A sequence of earthquakes and steam explosions in early 1991 signaled rising magma, allowing scientists and officials to issue warnings and evacuate many residents.
The climactic eruption on 15 June 1991 created a large caldera and injected enormous quantities of sulfur dioxide into the stratosphere. The resulting sulfate aerosols reflected sunlight and temporarily cooled global average temperatures. Typhoon Yunya arrived at the same time, worsening ash-related hazards.
Pinatubo’s eruption is sometimes confused with Mayon’s famous eruptions, but the two volcanoes have different shapes and histories. Mayon is known for its symmetrical cone, while Pinatubo’s 1991 event is especially important for its global atmospheric effects.