Privileged Planet: continental subduction allows life (Introduction)

by David Turell , Tuesday, March 02, 2021, 20:07 (1362 days ago) @ David Turell

And it also creates massive Earth movements as earthquakes and sudden volcanic activity:

https://www.sciencedaily.com/releases/2021/03/210302075346.htm

"Hours before the 2018 eruption of Sierra Negra, the Galápagos Islands' largest volcano, an earthquake rumbled and raised the ground more than 6 feet in an instant. The event, which triggered the eruption, was captured in rare detail by an international team of scientists, who said it offers new insights into one of the world's most active volcanoes.

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"For nearly two months in 2018, lava erupted from the volcano, covering about 19 square miles of Isabela Island, the largest island in the Galápagos and home to about 2,000 people and endangered animal species like the Galápagos giant tortoise.

"'The 2018 eruption of Sierra Negra was a really spectacular volcanic event, occurring in the 'living laboratory' of the Galápagos Islands," said Andrew Bell, a volcanologist at the University of Edinburgh."

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"The scientists captured data over 13 years as the volcano's magma chamber gradually refilled following the 2005 eruption, stressing the surrounding crust and creating earthquakes. This continued until June 2018, when an earthquake occurred on the calderas fault system and triggered the subsequent eruption, the scientists said.

"'We have this story of magma coming in and stressing the system to the point of failure and the whole system draining again through the eruption of lava flows," La Femina said. "This is the first time anyone's seen that in the Galápagos to this detail. This is the first time we've had the data to say, 'okay, this is what happened here.'"

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"Inside the Sierra Negra caldera is a "trap-door fault," which is hinged at one end while the other can be uplifted by rising magma. The scientists found the fault caused hills inside of the six-mile-wide caldera to lift vertically by more than 6 feet during the earthquake that triggered the eruption.

"Caldera resurgence, important to better understanding eruptions, had not been previously observed in such detail, the scientists reported in the journal Nature Communications.

"'Resurgence is typical of explosive calderas at volcanoes like Yellowstone, not the kind of shield volcanoes we see in the Galápagos or Hawaii," La Femina said. "This gives us the ability to look at other volcanoes in the Galápagos and say, 'well that's what could have happened to form that caldera or that resurgent ridge.''"

Comment: In order for us to live on Earth, we must put up with this dangerous process. We need all the knowledge we can use. It is all part of a pattern that our right to life comes with good and bad issues.