Catastrophe of an super eruption | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Consequences of an super eruption | Automatic translation | Updated April 20, 2013 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
These are supervolcanoes that cause super eruptions, they are a thousand times more powerful than the largest volcanic eruptions which mankind has witnessed in recent decades. The consequences of a super eruption is unimaginable so they are catastrophic. They can cause considerable damage to the scale of a continent and have cataclysmic effects for life on Earth. One of the most puzzling is that the island of Santorini with some volcanologists believe it is the cause of the disappearance of the Minoan civilization in the Aegean Sea, 3,600 years ago. It is likely that the legend of Atlantis as told by Plato in the 4th century BC, derived from the Aegean disaster. The islands of the Cyclades in the Aegean Sea are located along a micro plate boundary between the African plate and the Eurasian plate. The pressure of the large plates of the Aegean arc created these islands by the accumulation of lava and projections first submarine then aerial. The first phase of the disaster is characterized by many small earthquakes that will last for days and days with at times of strong shaking. Then the ashes and gases escape from the volcanic chimney, soil cracks and covers several decimeters ash. It is the harbinger of the great eruption disaster. | The upper part of the volcano collapses and falls into the magma chamber, it is the collapse of the caldera and huge boulders the size of a car spring as missiles. The power is enormous it is equivalent to tens of thousands of times the Hiroshima bomb. In the vast plume covering the volcano burst of lightning that fully illuminate the sky. The magma chamber is partially empty, the volcano spews tens of billions of tons of magma which are buried for a long time, the land under a hundred meters high ash, pumice and blocks. Pumice floating on the water covers a part of the sea a layer so thick (1 meter) that can be walked on. Large islands of pumice drift away by the waves, even by boat, you can not escape from this hell and the worst is to come. | Image: The beautiful Greek island Santorini is a volcanic island redesigned at the end of the sixteenth century BC (between 1650 and 1598 BC), a terrific explosion that engulfed the center of the island and disintegrated Santorini into several islets around the caldera. Its cliffs are of exceptional beauty that makes this place one of the most beautiful scenery in the world. Satellite image of the islands of Santorini, with the island of Santorini, to the right. This incomplete ring of 8 km in diameter and 85 km2, circumscribed islands of Thera and Therasia, which are the remains of the ancient island Kallistē before the volcanic collapse created the caldera. The supervolcano Santorini is stratovolcano Plinian. Index VEI = 6, in 1600 BC (see table below). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
Are we threatened by supervolcanoes? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The supervolcanoes have a flat structure and is difficult to detect. It is only after to have exploded when underground magma chamber collapses, we see the famous caldera supervolcano in the ground. These calderas of several tens of kilometers, are so great that we can not detect that from an aerial view. | Yes a super eruption threatens us but we do not know which. Image: Index classification of volcanic eruptions, by volume ejected material. The index of Explosivity or scale VEI (Volcanic Explosivity Index), was invented in 1982 by Chris Newhall of the U.S. Geological Survey and Steve Self at the University of Hawaii.
| Image: Nestled in the heart of the rainforest of Sumatra, the giant caldera supervolcano Toba, has impressive dimensions. It measures ≈ 30 km wide and ≈ 100 km long. The ancient caldera is now filled by a lake in the middle of which the tourist island of Samosir, embodying the old dome of the volcano. Lake Toba is the largest lake in Southeast Asia, its landscape is spectacular, with its high mountains and houses Batak. This oasis of tranquility is actually a supervolcano crater where live more than 20 000 inhabitants. The explosion took place, there are about 74 000 years. VEI index supervolcano Toba = 8. |