A volcanic explosion great enough to score six on the index happens, on average, about every century - Pinatubo in the Philippines hosted the last in 1991, while a thousand years or more may separate the colossal eruptions deserving of a VEI7.
Eruptions much smaller than Pinatubo didn't seem powerful enough to put a lot of debris into the stratosphere, but atmospheric scientist Susan Solomon of the University of Colorado, Boulder, and her colleagues report online today in Science that less-than-colossal eruptions did just that in recent years.
The author barely mentions the greatest tragedy in Icelandic history, the colossal volcanic eruption of 1783 which cut the island's population by a fifth, to just 40,000 people.
After the colossal 1980 eruption that killed 57 people and devastated 230 square miles of land, the volcano continued to explode for six years, falling into a brief slumber before roaring back in 2004, shooting ash and steam thousands of feet skyward.
This image shows the Earth to scale with a colossal solar filament eruption from the sun on Aug. 31, 2012 as seen by NASA's Solar Dynamics Observatory spacecraft.
Geologists were at last free to suggest that calamitous but infrequent events — powerful deluges, colossal landslides, gargantuan volcanic eruptions, supersonic impacts from extraterrestrial objects — did in fact play a role in shaping our world.
The researchers suggest that perhaps in both extinctions, a plume of lava may have already risen close to the surface, but the meteor impacts turned small eruptions into colossal ones.
The Day the World Exploded: August 27, 1883 April 2020) reports the astonishing scale of Krakatoa's eruption and the colossal destruction that followed.
The Volcanic Explosivity Index (VEI) devised by Newhall and Self (1982) describes the size of explosive eruptions; values range from 0 (gentle) to 8 (colossal).
