Geosféry

Geosféry refers to the layered structure of the Earth, composed of concentric spherical shells with distinct chemical and physical properties. This model describes the internal composition of the planet, divided primarily into the crust, mantle, outer core, and inner core. Each layer plays a critical role in defining Earth’s geophysical behavior, including tectonic activity, magnetic fields, and heat distribution.

The outermost layer, the crust, is solid and varies in thickness, ranging from about 5–70 kilometers beneath the oceans and continents, respectively. Beneath the crust lies the mantle, a thick, semi-rigid layer extending to roughly 2,900 kilometers deep. The mantle is composed of silicate minerals rich in iron and magnesium, and it conveys heat through convection currents, driving plate tectonics. The transition zone between the upper and lower mantle occurs at approximately 410–660 kilometers depth, where mineral phases change due to pressure variations.

Below the mantle is the outer core, a fluid layer of molten iron and nickel spanning from 2,900 to 5,150 kilometers deep. Its dynamic movement generates Earth’s magnetic field through the geodynamo effect, a process involving the motion of conductive fluids. The innermost layer, the inner core, is solid and composed primarily of iron with some nickel, extending to the planet’s center at around 6,371 kilometers. Despite extreme temperatures (estimated at 5,000–6,000°C), the inner core remains solid due to immense pressure.

The geosféry model is fundamental to geology, seismology, and planetary science, providing insights into Earth’s thermal evolution, volcanic activity, and seismic wave propagation. Advances in seismology, particularly the study of earthquake waves, have refined our understanding of these layers, though direct sampling remains limited to the crust. Comparative studies of other terrestrial planets, such as Mars and Venus, also rely on similar geosféry-based interpretations to infer internal structures.