Researchers from the Carnegie Institute and the Institute of Earth Sciences at academia Sinica have discovered the mechanism by which the presence of light elements in the iron core can affect the Genesis and stability of geodynamo. The study is published in the journal Nature Communications.
Life on Earth could not be formed as we know it, without a magnetic field produced by geodynamo – the phenomenon of permanent migration and convection of molten iron in the outer core.
Our planet was formed from a disk of dust and gas that surrounded the Sun at an early stage of development. Ultimately, the most dense material sank into the depths of the forming planet, creating layers that exist today — the core, mantle and crust. Although the core consists mainly of iron, seismic measurements show that it also dissolved some of the lighter elements such as oxygen, silicon, sulfur, carbon and hydrogen.
Over time the inner core crystallized and since then continuously cooled. However, until now the researchers do not know the answer to the question of whether the warmth spreading from the core into the mantle, itself manage or geodynamo this process requires the presence of light elements, which helps the heat to rise upwards. Understanding of the chemical composition of the nucleus can help to answer this question.
Silicates are the most common compounds in the Earth’s mantle. After oxygen silicon and iron is the third concentration in the earth’s crust element. That is why he is a likely candidate for a light element located in the iron core. The authors of the new study used laboratory model that simulates the conditions deep under the earth’s surface. Its use has enabled scientists to predict how the presence of the silicon will affect the heat transfer from the iron core of a planet into the mantle.
As a result, the researchers found that the concentration to about 8% silicon in the inner core can affect geodynamo so that the model accurately describes the experimental data. Now scientists plan to expand their study to understand how the presence of oxygen, sulfur and carbon in the core will affect the process of convection.
