A team of researchers at Princeton University in US and the Institute of Geodesy and Geophysics in China has discovered massive mountains in the earth’s mantle. Experts believe that this new discovery could change the understanding of the creation of this planet.Most school children learn that the Earth has three layers: a crust, mantle and core, which is subdivided into an inner and outer core. While that is not wrong, it does leave out several other layers that scientists have identified within the Earth.They have now discovered that the boundary between these layers can be very rough, resembling the mountain ranges and smooth plateaus of the Earth’s surface. The discovery could reveal lost continents’ final resting places. The deeper layers of the mantle are far beyond humanity’s capacity to study directly. However, we can understand the composition of the Earth’s inner and outer core in indirect ways, such as from seismic waves triggered by large earthquakes that bounce off the planet’s internal boundaries, just as light waves can be partially reflected by transitions between different densities of glass. Dr Jessica Irving of Princeton University applied the same idea to look at the more subtle differences in composition within the mantle.
Scientist discovered these mountains, as well as other topography on a layer located 660 kilometres straight down that separates the upper and lower mantle, during the study on an enormous earthquake that happened in Bolivia in the year 1994. It was one of the biggest earthquakes ever recordedand it measured 8.2 on the Richter scale.During the research, scientists used powerful computers and simulated the complicated behaviour of scattering waves in the deep earth.Further analysis revealed that the waves of earthquake often pass through straight when it encounters homogeneous rocks, while it gets reflect or refracts as it encounters any kind of boundaries or roughness. Researchers also noted that the roughness in this inner mantle is much more than the earth’s surface.
Lacking a formal name for this layer, the researchers simply call it “the 660-km boundary.”The researchers also examined a layer 410 km down, at the top of the mid-mantle “transition zone,” and they did not find similar roughness. The presence of roughness on the 660-km boundary has significant implications for understanding how our planet formed and evolved.