Monday, August 26, 2019

Manhattan-sized horde of floating rocks travels across the ocean

Tonga Islands: new submarine volcanic eruption discovered near Fonualei Island

From Mashable by Mark Kaufman

Somewhere beneath the waters of the tropical Pacific Ocean, likely around the island of Tonga, a volcano recently erupted.

 Localization with the GeoGarage platform (Linz nautical chart)

The proof lies in a sprawling raft of extremely lightweight volcanic rock called pumice, which is so porous that it floats. NASA posted satellite images of the drifting mass on Aug. 23, though the geologic display was first spotted in mid-August.
"Many of the world’s volcanoes are shrouded by the waters of the oceans," wrote NASA.
"When they erupt, they can discolor the ocean surface with gases and debris. They also can spew masses of lava that are lighter than water."

NASA spotted a floating island, and a volcano is to blame

As of Aug. 13, the raft, in total, appeared larger than the island of Manhattan, which is about 23 square miles in size.
Pumice is created during explosive volcanic eruptions, wherein the gas trapped molten rock explodes out of the scorching material in a violent pressure release.

Adventuring sailors on a catamaran met the great pumice raft up close.
They encountered floating pumice ranging in size from marbles to basketballs, some of which jammed their rudders.
The team also noted the ominous smell of sulfur wafting through the air, and posted their experience on Facebook.

 On August 9, 2019 we sailed through a pumice field for 6-8 hours, much of the time there was no visible water.
It was like ploughing through a field.
We figured the pumice was at least 6” thick.

The oceans will incrementally disperse this fleeting geologic wonder, but it's common for some marine life to hitch a ride on the floating stones, and journey across the globe.

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