Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows
Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 degrees hotter than in a previous experiment run 20 years ago. These measurements confirm geophysical models that the temperature difference between the solid core and the mantle above, must be at least 1500 degrees to explain why the Earth has a magnetic field.
For more information about this study, see the press release from the European Synchrotron Radiation Facility.
Ocean Volcanic Rocks Contain Samples of Recycled Crust
Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials from the early Earth’s crust. But decisive evidence for this phenomenon has proven elusive. New research from a team including Carnegie’s Erik Hauri demonstrates that oceanic volcanic rocks contain samples of recycled crust dating back to the Archean era 2.5 billion years ago. Their work is published in Nature.
Oceanic crust sinks into the Earth’s mantle at so-called subduction zones, where two plates come together. Much of what happens to the crust during this journey is unknown. Model-dependent studies for how long subducted material can exist in the mantle are uncertain and evidence of very old crust returning to Earth’s surface via upwellings of magma has not been found until now.
For more information about these results, see the press release from the Carnegie Institution.
March 11, 2011 - 9.0 Magnitude Earthquake and Tsunami Hits Japan
On March 11, 2011, a 9.0 magnitude earthquake hit at 02:46:23 pm in the afternoon near the east coast of Honshu, Japan. The quake was 24.4 km deep at its epicenter, and occurred as a result of thrust faulting on or near the subducting plate boundary between the Pacific and the North American tectonic plates. The earthquake was preceded by numerous large foreshocks over the two preceding days, beginning on March 9, with a M 7.2 event approximately 40 km from the March 11 epicenter.
Following the major shock, which was the largest in Japan for 140 years (and one of the largest in the world for the past 100 years), a massive tsunami, reaching 10 meters high, hit the coast of Japan and caused widespread devastation and loss of life across the region. As of March 14, several thousand have been found dead, with more thousands missing. The tsunami continued to propagate across the Pacific Ocean, causing damage in Hawaii, as well as in California. There have been hundreds of aftershocks following the major earthquake, with more than two dozen at a magnitude of 6 or greater. The region is continuing to deal with tsunami warnings, which are complicating recovery efforts.
An additional complication is that the tsunami damaged reactors at the Daiichi nuclear plant in Fukushima. To date, there have been at least three explosions at the plant, which officials believe were due to explosive release of steam. Officials are still working to cool the reactors, and determine their condition. In the meantime, as a result of the devastating earthquake, tsunami, and nuclear reactor damage, hundreds of thousands of people have been displaced, many having lost their homes to the tsunami.
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