EXPLAINER: Why Tonga eruption was so big and what’s next

By NICK PERRY
Associated Press

WELLINGTON, New Zealand (AP) — The eruption of the undersea volcano near Tonga over the weekend was incredibly explosive but also relatively brief. The plume rose into the air more than 19 miles but the eruption lasted only about 10 minutes, unlike some big eruptions that can continue for hours. New Zealand scientists Shane Cronin says the power of the eruption of the Hunga Tonga Hunga Ha’apai volcano ranks among the world’s biggest over the past 30 years, and the height of the plume of ash, steam and gas was comparable with the huge 1991 eruption of Mount Pinatubo in the Philippines, which killed several hundred people. Many scientists were surprised that an eruption could produce a Pacific-wide tsunami that smashed boats in New Zealand, caused an oil spill and two drownings in Peru.