Recent research shows climate change is causing increased volcanic activity by enabling fault. Marion Jegen and colleagues at GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, continues to observe the amount of data that appears on a computer screen.
Computers make global warming scenarios related to the melting of polar ice caps and some mountains. German geophysicist also include the results of drilling the seabed at a subduction zone, the waters of Central and South America. "What we found was the opposite of the view of all people today," Jegen said to Livescience on Wednesday (January 2, 2013).
Jegen and geological research team found indications that climate change has increased the frequency of volcanic eruptions. This finding is the opposite of all this research that a volcanic eruption is dramatically changing the climate.
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| Rapid global warming has caused an increase in volcanic eruptions in the past, a new study finds less slippery. (Picture from: http://www.livescience.com/) |
For example, the mass extinction of living things at the end of the Permian period, millions of years ago. Experts believe it happened after the eruption of super-volcanoes that constantly and cool climate and poisoned the atmosphere and oceans.
Climate change is very rapid since a few million years ago. Today, we are entering the end era of of the Ice Age. These changes make the continental glaciers melt and raising sea levels. For example, Sundas began sinking since 10 thousand years so now the Java Sea.
From computer models, glaciers seen melting that reduce pressure on the continent. While sea level rise increases the pressure on the earth's crust on the seafloor. Pressure changes that trigger an increase in volcanic activity.
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| Ash layers in cores from the Pacific seafloor. (Picture from: http://www.gizmag.com/) |
The research team reviewed the results of deep-sea drilling South and Central America. Sediment obtained indicate, within a period of 1 million years there have been drastic changes in the climate.
Every time there is global warming, a layer of volcanic ash (tephra) in the sediments. "In some places, such as in Costa Rica, increased volcanic activity reaches 5-10 times after a period of glaciers melting," said Jegen.
This study did not assess whether modern climate change (referred to as a result of human activity) affect the increased frequency of volcanic eruptions. Although in theory, Jegen said, it's possible.
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| Worldwide volcanic activity increases 1875-1993. (Picture from: http://bibliotecapleyades.lege.net/) |
Jegen explained, will not necessarily climate change followed by a volcanic eruption. He predicts a lag of about 2,500 years. If we change the climate, he said, would not really be certain things happen in a few thousand years later.
Before Jegen and colleagues released the results of their study, the study by the Research Center of the University College London Hazard also concluded the same thing. In August 2007, Bill McGuire from the agency wrote in the Guardian Unlimited. According to McGuire, one of the features that can change the balance of power in the Earth's crust is a layer of ice, in the form of glaciers. This ice sheet covered most of the earth around the poles, plus mountains at all latitudes.
The mass of the ice crust that is pressing on the backfoot. When the ice melts, the crust was no longer have anything on it so it can clamp quickly enough. Rebound is actually happening now, as a result of the end of the last Ice Age.
Areas crust could change and rebound the stresses and enable the fault / fracture and volcanoes. McGuire pointed Iceland, which has a layer of ice in the mountains of the Eyjafjallajokull volcano. "Unloading effects could trigger an eruption," he said.
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| Average Earth Surface Temperature Changes from 1870 to 1899). (Picture from: https://www.meted.ucar.edu/) |
With the dynamics of changes in the earth's crust, faults become unstable. This brings other problems. "It's not just about volcanoes. If you load and unload an active faults, you are responsible for the actions of triggering earthquakes," McGuire said.
He showed some evidence in the event of climate change of the past. At the end of the Ice Age, he said, there was increse massive of seismicity along the edge of the Scandinavian ice sheet. This sparked a large underwater landslide that produced a tsunami.
Roland Burgmann, a geologist at the University of California, Berkeley, agreed that changes in ice cover can have a significant effect on the earth's crust. But he hopes there is more research to explain this phenomenon. And now Marion Jegen and his friends have been answering Burgmann's questions. *** [EKA | FROM VARIOUS SOURCES | GIZMAG | [LIVESCIENCE | UNTUNG WIDYANTO | KORAN TEMPO 4108]
Water Pressure
The melting ice raises additional consequences because of all the water eventually empties into the sea. Global warming causes rising sea surface temperatures and the water expands, so-called thermal expansion process.
Improved water mass puts stress on fault / fracture near the shoreline. Added weight of the water on the Earth's crust caused tensional and compression conditions. "Just like when you bend a plank of wood," said Bill McGuire of University College London Research Centre Hazard.
The compression power can push out any magma in the kitchen and triggered the eruption of the volcano. This mechanism is believed to be the cause of the eruption of Pavlof volcano seasonally in Alaska. This mountain erupts every winter when the sea level higher.
McGuire conducted a study published in the journal Nature in 1997. He attributed the relationship between sea level rise and volcanic activity in the Mediterranean over the last 80 thousand years. He found that, when the sea level rose quickly, volcanic eruptions has increased 300 percent.
Global warming is causing the melting of glaciers and sea levels rose so quickly. This geological catastrophe, he is comparable to an increase in sea surface quickly seeara we have seen in the past 15 thousand years. *** [EKA | FROM VARIOUS SOURCES | GIZMAG | [LIVESCIENCE | UWD | KORAN TEMPO 4108]
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