In 1971, a young geologist named Mike Voorhies came across a perfectly preserved.skull of a young rhinocerous in eastern Nebraska. It turned out that he had just dicovered the most extraordinary fossil beds of North America, which is known today as the Ashfall Fossil Beds State Park. It was a dried up water hole around which was a mass grave for many animals. All had died due to a sudden event which occured two million years ago in the Miocene period. The animals were found to be buried under volcanic ash 3 meters deep. It was intriguing that there were no volcanos nor have there been any volcanoes in Nebraska. At first they thought that the animals were buried alive, but soon realized that the animals hadnt died suddenly. They were all found to be suffering from hypertrophic pulmonary osteodystrophy, which you contract when you breathe a lot of abrasive ash.. Such ash is found for hundreds of miles around this area. The ash at that time would have buried the grass and turned the water in the watering hole into an undrinkable sludge. The million dollar question was where did all this ash come from? Voorhies sent ash samples to colleagues in the western United States asking if anybody could help. Bill Bonnichsen from Idaho Geological Survey informed him that the ash samples matched a volcanic deposit from a place called Bruneau-Jarbidge in southwest Idaho, which is located 1600 kms. away. It is a known fact that there is a huge cauldron of magma under the western United States, which erupted cataclysmically every 6,00,000 years. The last eruption in this region also occured six hundred thousand years ago! The hotspot is still there in what is known today as the Yellowstone National Park.
In 1960, Bob Christiansen of the United States Geological Survey tried looking for the Yellowstone volcano, but strangely enough, couldnt find it. He was particularly looking for a caldera (Latin for cauldron), which is a vast subsided pit which occurs after a single mighty rupture. Christiansen happened to accidentally glance at some high altitude pictures taken by NASA of the Yellowstone park. It suddenly dawned on him that the whole park 9000 square kilometers of it was the caldera. The explosion had left a crater 65 kilometers wide. That is why he couldnt spot it from the ground. At some point in the past Yellowstone must have blown up with a violence, the magnitude of which cannot just be imagined. Prof Bill McGuire of University College, London says that when it erupted one wouldn't be able to get within one thousand kilometers of it!
Yellowstone sits on top of an enormous hotspot. Beneath the surface lies a magma chamber which is about 72 kms. across. The pressure from the magma chamber on its crust is what has lifted the park and sorrounding areas half a kilometer higher. The heat from the hotspot is what powers all the park's geysers, vents and hotsprings. Since its first eruption 16.5 million years ago, it has blown up about a hundred times. The last eruption was atleast a thousand tiimes bigger than St. Helens, and the one before that was atleast 2500 times bigger. The yellowstone eruption which occured 2 million years ago, threw up enough ash to bury New York state to a depth of 20 meters and California to a debth of 6 meters. The ashfall from the last eruption coverd all or parts of 19 western states.
The last supervolcano erupted in Toba, Northern Sumatra 74000 years ago. Greenland ice cores reveal that the Toba eruption was followed by 6 years of volcanic winter. The event might have carried humans to the brink of extinction, reducing the global population to a few thousand individuals. For the next 20.000 years the population remained at the few thousand level. That is a long time to recover from a single blast. A supervolcanic eruption like Yellowstone could wipe out mankind from the face of this earth.
If the Samalas volcano which occured in 13th century was the mother of volcanoes, the yellow stone volcano will easily qualify to be the great great grand mother of volcanoes. All the experts agree on one thing, the yellowstone volcano is certain to erupt, and if and when it does heaven help us. The worst part is that it is due anytime now.
Source:
Bill Bryson: A short history of nearly everything
In 1960, Bob Christiansen of the United States Geological Survey tried looking for the Yellowstone volcano, but strangely enough, couldnt find it. He was particularly looking for a caldera (Latin for cauldron), which is a vast subsided pit which occurs after a single mighty rupture. Christiansen happened to accidentally glance at some high altitude pictures taken by NASA of the Yellowstone park. It suddenly dawned on him that the whole park 9000 square kilometers of it was the caldera. The explosion had left a crater 65 kilometers wide. That is why he couldnt spot it from the ground. At some point in the past Yellowstone must have blown up with a violence, the magnitude of which cannot just be imagined. Prof Bill McGuire of University College, London says that when it erupted one wouldn't be able to get within one thousand kilometers of it!
Yellowstone sits on top of an enormous hotspot. Beneath the surface lies a magma chamber which is about 72 kms. across. The pressure from the magma chamber on its crust is what has lifted the park and sorrounding areas half a kilometer higher. The heat from the hotspot is what powers all the park's geysers, vents and hotsprings. Since its first eruption 16.5 million years ago, it has blown up about a hundred times. The last eruption was atleast a thousand tiimes bigger than St. Helens, and the one before that was atleast 2500 times bigger. The yellowstone eruption which occured 2 million years ago, threw up enough ash to bury New York state to a depth of 20 meters and California to a debth of 6 meters. The ashfall from the last eruption coverd all or parts of 19 western states.
The last supervolcano erupted in Toba, Northern Sumatra 74000 years ago. Greenland ice cores reveal that the Toba eruption was followed by 6 years of volcanic winter. The event might have carried humans to the brink of extinction, reducing the global population to a few thousand individuals. For the next 20.000 years the population remained at the few thousand level. That is a long time to recover from a single blast. A supervolcanic eruption like Yellowstone could wipe out mankind from the face of this earth.
If the Samalas volcano which occured in 13th century was the mother of volcanoes, the yellow stone volcano will easily qualify to be the great great grand mother of volcanoes. All the experts agree on one thing, the yellowstone volcano is certain to erupt, and if and when it does heaven help us. The worst part is that it is due anytime now.
Source:
Bill Bryson: A short history of nearly everything
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