An eight-point scale called the "volcanic explosivity index" (VEI) allows you to compare eruptions and volcanoes.
你可以通过“火山爆发指数”(VEI)来比较喷发和火山，它把火山爆发分为8个等级。
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Kikai weighed in at 7 on the standard volcanic explosivity index (VEI), which runs from 1 to 8, VEI 8 being reserved for the sort of mega-eruptions that cause ice ages and mass extinctions.
Reasons to worry: Santa María's last big blast was one of the four largest volcaniceruptions in the 20th century, registering a VEI magnitude of 6 and leaving a 700-by-1,000 meter craterbehind.