There may be a zone of silicon “snow” between the Earth’s core and the mantle. In this respect informs Arizona State University press office.
Deep under the Earth’s surface is the outer core, which consists of a 2,000 km thick layer of liquid metal alloy. Although the outer core is located at a depth of 3000 km from the surface, it affects life on the surface because it is associated with the formation of magnetic fields. Therefore, scientists are interested in how the contact zone between the silicate mantle and the metal core is regulated, including explaining a number of anomalies identified during seismic studies.
American geologists conducted a series of laboratory experiments in which they recreated conditions at this boundary. An iron-silicon alloy loaded with hydrogen and argon impurities was placed between the diamond anvils. With their help, the material was compressed to pressures specific to thousands of kilometers (1.23 million atmospheres) and heated with a laser to 3.2 thousand degrees. It turned out that under these conditions, iron-silicon crystals were formed, which gradually settled in the core.
“If there is enough hydrogen and silicon in the outer layers of the Earth’s core, strange particles of silicon “snow” can appear inside. Our calculations show that such exotic silicon “snows” begin to fall at the boundary between the core and the mantle, and may also play an important role in cooling the Earth’s interior at great depths,” the authors explain.
Scientists believe that the presence of this type of snow can explain many of the anomalies that slow the propagation of seismic waves.