Earth hotter than Sun

London 29 Sep 99 Britisch scientists used quantum physics and two powerful Cray 3TE supercomputers to devise a method to determine the melting point of iron under the extreme pressures, that constitues the Earth's core. Their results, published in the science magazine Nature, calculated that the iron melting temperature is 6500 Celsius, about as hot as the Sun's surface. Considering the 10 percent of impurities in the Earth's core, the researchers reduced the figure to 5500 Celsius.

The researchers at the University College London said that the novel approach they used in the study, as well as the results, which is believed the most accurate yet achieved, may have major implications for understanding the dynamics of the Earth.

"It's crucial to know the temperature of the Earth's core," explained Professor David Price, one of the researchers to Nature, "There's tremendous heat energy stored down there. The heat flowing out of the core causes earthquakes, volcanoes and the drift of continents."

According to Professor Price and his colleagues, the key to the calculation is to find out the melting temperature of iron at the stupendous pressure in the core.

The team reasoned that the core, consisting mainly of iron, turns from solid to liquid form near the Earth's center.

"The idea that we are sitting on top of a seething mass of molten iron as hot as the Sun may be pretty scary", commented Professor Mike Gillan, one of the co-author of the Nature paper.

"But scientifically the core temperature is important because it is a crucial in understanding how the Earth changes over time," he said.

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