The upper mantle is the layer of Earth's interior located directly beneath the Earth's crust, extending from about 410 to 660 kilometers deep. It is primarily composed of solid rock material and plays a key role in the movement of tectonic plates and the overall dynamics of the Earth's lithosphere. Researchers study the upper mantle to better understand processes such as mantle convection, plate tectonics, seismic activity, and the formation of geological features such as mountains and ocean basins. By studying the upper mantle, scientists can gain insights into the structure and dynamics of the Earth's interior and how it influences the surface processes that shape our planet.