undermantles

Undermantles are geological layers located beneath the Earth's crust and above the Earth's core. This region is generally considered to be the uppermost part of the mantle. The boundary between the crust and the mantle is known as the Mohorovičić discontinuity, or Moho. The undermantle is primarily composed of silicate rocks, rich in magnesium and iron. Its temperature increases with depth, and while largely solid, it exhibits plastic behavior over geological timescales, allowing for convection currents. These currents are a fundamental driving force behind plate tectonics, influencing phenomena such as earthquakes and volcanic activity. The composition and physical state of the undermantle vary considerably across different regions of the Earth. Research into the undermantle is often conducted through the study of seismic waves, which travel through the Earth and reveal information about its internal structure. Direct sampling of the undermantle is not currently feasible due to its depth and extreme conditions. Understanding the undermantle is crucial for comprehending the dynamic processes that shape our planet's surface.