Earth's inner core is 1000C hotter than previously thought, will affect many earth measurements including earthquakes, Science study-BBC

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4/26/13, "Earth's core far hotter than thought," BBC, J. Palmer

"New measurements suggest the Earth's inner core is far hotter than prior experiments suggested, putting it at 6,000C - as hot as the Sun's surface....

Experiments outlined in Science used X-rays to probe tiny samples of iron at extraordinary pressures to examine how the iron crystals form and melt....

Measurements in the early 1990s of iron's "melting curves" - from which the core's temperature can be deduced - suggested a core temperature of about 5,000C.

"It was just the beginning of these kinds of measurements so they made a first estimate... to constrain the temperature inside the Earth," said Agnes Dewaele of the French research agency CEA and a co-author of the new research.

"Other people made other measurements and calculations with computers and nothing was in agreement. It was not good for our field that we didn't agree with each other," she told BBC News.

The core temperature is crucial to a number of disciplines that study regions of our planet's interior that will never be accessed directly - guiding our understanding of everything from earthquakes to the Earth's magnetic field. 

"We have to give answers to geophysicists, seismologists, geodynamicists - they need some data to feed their computer models," Dr Dewaele said.

The team has now revisited those 20-year-old measurements, making use of the European Synchrotron Radiation Facility - one of the world's most intense sources of X-rays."...


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