Tonga's Hunga Tonga volcano just had one of the most violent volcano eruptions ever captured on satellite. pic.twitter.com/M2D2j52gNn
— US StormWatch (@US_Stormwatch) January 15, 2022
Hunga #Tonga-Hunga Ha'apai #eruption at 04:00 UTC on Jan 15.
— Seán Doran (@_TheSeaning) January 15, 2022
images courtesy #Himawari8 pic.twitter.com/Zk8uepybuX
JUST IN: The National Tsunami Warning Center has issued a tsunami advisory is in effect for the entire West Coast and Alaska in the wake of an undersea volcanic eruption near Tonga. https://t.co/6QAUay90w7
— ABC News (@ABC) January 15, 2022
Ninety percent of the population of Tonga, a little over a hundred thousand people, lives on the island of Tongatapu, a low island with a central lagoon. The highest elevation is 92 feet above sea level, but the vast majority of the land is less than 10 feet above sea level. The island is fringed by a a circle of reef that varies from a few hundred feet to up to a mile or more from the shoreline. The soil is quite fertile and underlain by a thick layer of porous limestone. There are no rivers or streams on the island. Water drains into the ocean by percolating through the limestone. A freshwater lens floats underground on top of saline groundwater so wells into the lens supply drinking water, augmented by cisterns replenished by rainwater runoff. It's like the island was designed for weathering tsunami events. But there is no high ground to which to evacuate without taking a boat to the neighboring high island of Eua where the highest elevation is over a thousand feet above sea level.
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