On the mechanisms of volcanic super-eruptions

The new model of volcanic super-eruptions suggests that these titanic disaster occurring about every 100,000 years, may be the result of some combination of geometry and temperature of magma chambers.

For tens of thousands of years, the viscosity of the rock surrounding the cell, causing the growth of deep pressure, and raises the ceiling camera up until the line voltage in the rock, finally, do not make a volcanic caldera explode.

"You can compare it to cracks that formed in the crust of bread when baking," said lead author of the article, Patricia Gregg of the University of Oregon. "As soon as the magma chamber is compressed in the depth of the rock in the surface cracks, which are designed to remove the increasing tension of the dome."

"Sooner or later, the cracks grow, and spread down to the core of the magma chamber. When we are dealing with very large volcanoes and cracks penetrate deep enough into them, they can destroy the wall of the chamber, causing the collapse of its dome, and an extensive eruption. "

Eruptions of supervolcanoes can affect even the global climate on a global, leading, for example, to ice ages.

Volcanic eruption in Huckleberry Ridge in Yellowstone Park about 2 million years ago — one of the largest eruptions of supervolcanoes in history — was 2000 times more powerful than the volcanic eruption of St. Helena in 1980. There are also traces of other super-eruptions — in Japan, New Zealand, the Andes, and Lake Toba in Sumatra.

"After the collision with a meteorite, these super-eruption — the worst natural disasters that may face our planet," said Patricia Gregg. "Huge amounts of rock thrown into the air, destroying the environment, and creating a gas cloud that can cover the planet for many years."

Earlier models were based on the internal trigger pulse camera, but no visible evidence to support this theory suggests that the trigger is on the camera.

"Instead of having to deal with these super-eruptions" as is ", most of the models simply took small historic eruptions and tried to scale them to the size of a super-volcano," says co-author Shanaka de Silva.

"Those of us who really studied these phenomena have long known that such a super-eruption — is not just a proportional increase in incidents like the eruption of Krakatoa or Mount Mazamas, the relationship is not linear. And this is confirmed by observation. "

For the appearance of such a colossal structure magmatic need specific conditions, and this explains why natural disasters occur so infrequently.

Eruptions can fuel giant lava reservoirs of 10-15 thousand cubic kilometers, with regular breaks of magma of underlying layers, which lead to a softening of the surrounding rock, and allow the chamber to expand, writes MIXEDNEWS citing theepochtimes.com

In contrast, the smaller chamber volume can emit lava more frequently, up to the maximum pressure.

In Yellowstone volcanic activity takes place constantly, but super-eruption in the near future is expected.

"Raising the surface at Yellowstone right now is on the order of a few millimeters," says Patricia Gregg. "At the time of the eruption in the Huckleberry Ridge, elevation of Yellowstone region was hundreds of meters, and probably about a kilometer."

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