Aestus Ajith

Does dark magma lurk in deep Earth? A key to understanding Earth's evolution is to look deep into the lower mantle—a region some 400 to 1,800 miles (660 to 2,900 kilometers) below the surface, just above the core. Data have suggested that deep, hot, fluid magma oceans of melted silicates, a major Earth material, may reside above the core-mantle boundary. Researchers including Carnegie's Alex Goncharov have found, using high-pressure experiments with a proxy material, that the deep Earth materials conduct far less heat under increasing pressure than previously thought. The finding suggests that pressure is more important than current thinking and it is in direct contrast to what is found with the most abundant heat-conducting substance in the vicinity. The results indicate the presence of dense, dark magma heat traps that could affect the flow of heat across the core-mantle boundary revealing a different model of heat transport in this region. The research is ...

Missing link in metal physics explains Earth's magnetic field Conception of Earth's core overlaid by the electronic structure of iron; the width (fuzziness) of the lines results from the electron-electron scattering. Image courtesy of Ronald Cohen. Credit: Ronald Cohen Earth's magnetic field is crucial for our existence, as it shields the life on our planet's surface from deadly cosmic rays. It is generated by turbulent motions of liquid iron in Earth's core. Iron is a metal, which means it can easily conduct a flow of electrons that makes up an electric current. New findings from a team including Carnegie's Ronald Cohen and Peng Zhang shows that a missing piece of the traditional theory explaining why metals become less conductive when they are heated was needed to complete the puzzle that explains this field-generating process. Their work is published in  Nature . The center of the Earth is very hot, and the flow of heat from the planet's center to...

New theory suggests magnesium could be the key to understanding Earth's magnetic field Two types of chemical convection in Earth's core. Precipitating a thin layer of magnesium-rich minerals at the top of the core provides as much energy for the magnetic field as forcing silicon and oxygen out of the entire inner core. Credit: Joseph O'Rourke A pair of planetary scientists has come up with a new theory to help explain the mechanism behind the generation of the Earth's magnetic field. In their paper published in the journal  Nature , Joseph O'Rourke and David Stevenson, both with the California Institute of Technology, suggest that magnesium that made its way to the core of the planet during its early history could be the key to understanding how the magnetic field was generated in the past and what drives it in the present. Bruce Buffett with the University of California offers a  News & Views  piece on the work done by the team in the same jour...

Credit: Wikimedia Commons There are several things that people often bring up when discussing obvious facts, such as the sum of two and two equaling four, the Earth traversing around the sun once a year ( not everyone  understands this, actually), or perhaps the shape of the Earth. However, commonly held scientific facts are not always as self evident as they appear to be.  Knowledge that we take for granted in the twenty-first century, may have been mind boggling in centuries past….or was it? For example, we take the fact that the Earth is a “sphere” for granted (or almost a perfect spherical, it bulges at the equator). But how do you know the shape of the Earth is curved?  What piece of knowledge convinced you of this fact? The likely answer is that we have pictures of the Earth from outer space, showing its curvature.  But this was a fact that was known long before we had any cameras in space. In fact, without this knowledge, we would have never made it ...