The 1991 eruption of Mt. Pinatubo
Picture supplied by the EOS IDS Volcanology Team
Mt. Pinatubo, the Phillipines, erupted in June 1991 with global effects on weather and climate. It discharged 5 billion cubic meters of ash and pyroclastic debris (including 20 to 30 megatons of sulphur dioxide and aerosols) into the atmosphere via eruption columns which were 18km wide at the base and had heights of up to 30km. The volcanic cloud circled the Earth in just three weeks and covered about 42% of the planet's surface in just two months. It was the second largest eruption this century (after the 1912 Mt. Katmai eruption) and managed to lower the world temperatures by an average of 1oC.
Click on the thumbnail for T.O.M.S. satelite images of the movement of the volcanic cloud around the Earth (91K link).
The Pinatubo volcanic cloud was particularly rich in Sulphur Dioxide, a key element in the formation of aerosols (other volcanic eruptions sometimes contain greater proportions of other minerals). Global cooling took place on the scale it did because the aerosols were smaller than 2µm in diameter, so increasing the planetary albedo.
This site was created by Chris Garrett (cg6145@bris.ac.uk)
Last updated 26th April 1997