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Possible extinction by supervolcanoes

To those who have watched The Day After Tomorrow would find this title very familiar to them. In fact this was told by a geographer, Jack Hall, in a meeting that aimed to come out with a solution to the world’s climatic shift in the movie.

Information below obtained from the Discovery Channel.

WARNING: The article has been summarized, but it might still be very wordy to my readers. If you do not like to read wordy stuff, please move on to other posts below this post.

The world’s first national park, the Yellowstone National Park sits atop one of the largest active volcano on earth. Yellowstone National Park sits atop a subterranean chamber of molten rock and gases so vast that the region, known for its geysers and grizzles, is arguably one of the largest active volcanoes in the world.

Click for larger image. Supervolcanoes, such as the one at Yellowstone, experience a violent birth when a vast reservoir of magma rises from the hot spot and creates intense pressure beneath the earth’s crust. As pressure from the magma chamber builds, the ground above bulldozes upwards.

Then, at its breaking point, the ground and rupture in an explosion powerful enough to spew magma, ashes and gases far into the atmosphere in volumes so large that debris can rain down for thousands of square miles.

Click for larger image. During the period that the Yellowstone region has been aligned above the hot spot, three major eruptions had occurred.

While many visitors to Yellowstone National Park may be oblivious to the science at work, geologists and volcano experts have long known about the region’s explosive prehistoric past.

The image above shows the projected area of ash fall of different volcanic eruptions. We can look to past eruptions to see what kind of damage a future supervolcano would bring.

Mt St Helens, 1980 (white) – Ejected about one quarter cubic mile of ash and lava. 57 killed. Ash fell over an area of 22,000 square miles. Particles of ash circled the globe for 2 weeks. Volcanic Eruption Index (VEI) – 1.

Yellowstone, 640,000 yrs ago (red) – Ejected about 240 cubic miles of ash and lava. Dropped several feet thick of ash at most parts of Western US. Volcanic Eruption Index (VEI) – 8.

Yellowstone, 2.1 million yrs ago (cyan) – Ejected about 600 cubic miles of ash and lava. Dropped several feet thick of ash at most parts of Western US. Volcanic Eruption Index (VEI) – 8.

A full-scale eruption of the Yellowstone hot spot would result in a major disaster of global proportions. It would obliterate the entire Yellowstone National Park and nearby communities, spread ground-glass-like volcanic ash from the Pacific coast to the Midwest, and cause worldwide weather changes from the airborne dust and gases, according to Smith, who described the potential effects in detail in his book Windows Into the Earth, published in 2000.

The 1,080-square-mile Toba caldera is the only supervolcano in existence that can be described as Yellowstone’s “big” sister.

About 74,000 years ago, Toba erupted and ejected almost three times as much volcanic ash as the most recent major Yellowstone eruption (Lava Creek, 630,000 years ago) and about 12 percent more than Yellowstone’s largest eruption (Huckleberry Ridge, 1.8 million years ago). That comes to several thousand times more material than erupted from Mount St. Helens in 1980.

New Zealand’s Taupo caldera has been filled by water, creating what many describe as one of the world’s most beautiful landscapes.

Lake Taupo itself was created by a massive eruption 26,500 years ago. The caldera — the collapsed and subsided basin left after the huge eruption — became today’s lake.

But Taupo did not die. The 485-square-mile caldera let loose again in the year A.D. 181, with estimates of ash and magma reaching as high as 22 cubic miles. That’s on the order of a hundred times more than Mount St. Helens.

One of the most recently troubling calderas in the world is the 150-square-mile Aira caldera in southern Japan, on the edge of which sits the city of Kagoshima.

After a century of peace, the Sakura-jima volcano, which forms part of the Aira caldera, awoke on Jan. 10, 1914, and gave local residents two days’ notice of its intentions by letting loose hundreds of earthquakes.

On Jan. 12, after 23,000 people and their farm animals living on its flanks were evacuated, Sakura-jima erupted with ash, steam and lava. It was not really a super eruption, but it taught people a lot about how volcanoes erupt.

There was another eruption in 1946, and since 1955 Sakura-jima has had hundreds of small eruptions every year. The biggest eruptions, however, took place 22,000 years ago when 14 cubic miles of material burped out of the ground and formed the Aira caldera, which is now largely Kagoshima Bay. That is equal to about 50 Mount St. Helens eruptions.

While a worst-case-scenario supervolcano eruption sometime in the future would be catastrophic for large parts of the world, that destruction would be minor compared with what scientists believe could be the largest lava flow in Earth’s history: the Siberian Traps of 251 million years ago.

The gigantic lava flow in Siberia lasted upward of a million years and flooded an area about the size of the lower 48 United States with layer upon layer of dark basalt lava — thousands of feet thick.

Some geologists suspect the eruption was caused by an extra-large plume of hot material welling up from the edge of the Earth’s core. But what makes it especially important is that the Siberian Traps is the prime suspect in wiping out 90 percent of all living species 251 million years ago — the most severe extinction event in Earth’s history.

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