Scientists have spotted a thick layer of melted rock beneath the Earth’s crust that could be part of a fluid band of hot magma circling the globe. The magma ring has until now remained a theory. The molten-rock layer is 10 miles thick and can’t be seen, felt or smelt from the surface. Researchers Daniel Toffelmier and James Tyburczy of Arizona State University found the layer using a relatively new technique that measures changes in weak electrical currents flowing through the Earth’s mantle rock. The current is created when the solar wind, a continuous flow of charged atomic particles emitted by the sun, interact with Earth’s magnetic field, called the magnetosphere. The chemical make-up of the rocks affects their conductivity. By measuring changes in the current at different depths, the scientists were able to detect distinct rock layers, including the ‘invisible’ magma layer. ‘Rocks are semiconductors,’ Tyburczy said. ‘And rocks with more hydrogen embedded in their structure conduct better, as do rocks that are partially molten.’ The discovery, detailed in the June 21 issue of the journal Nature, partially confirms a recent hypothesis by two Yale University geoscientists, which states that a band of molten […]