The Earth Internal Structure

(Core, Mantle and Crust)

The Earth's interior is composed of several distinct layers, each characterized by its unique composition, physical properties, and behavior. These layers are divided based on their depth from the surface and the changes in the physical and chemical properties observed at different depths.

At the core, which is the innermost layer and surrounded by other layers, lies a dense region primarily composed of iron and nickel. Due to its composition, this layer is commonly referred to as Nife (a combination of Nickel and Ferrum) and has a density greater than 11.0. The core itself consists of two sub-layers: a solid inner core and a semi-liquid outer core. The boundary between these two layers is located at a depth of approximately 2,900 kilometers.

The innermost layer of the Earth is the core, which is divided into two regions: the solid inner core and the liquid outer core. The solid inner core has a radius of approximately 1,220 kilometers and is primarily composed of iron and nickel. The immense pressure at the core's center keeps the iron in a solid state despite the high temperatures. The temperature at the inner core boundary is estimated to be around 5,500 to 6,000 degrees Celsius.

Surrounding the solid inner core is the liquid outer core, which is a semi-liquid layer with a thickness of about 2,300 kilometers. The outer core consists of molten iron and nickel and is responsible for generating the Earth's magnetic field through a process called the dynamo effect. The temperature in the outer core ranges from 4,000 to 5,000 degrees Celsius.

The layer above the core is the mantle, which accounts for the largest portion of the Earth's volume. The mantle extends from the core-mantle boundary to the Earth's surface. The mantle is predominantly made up of magnesium and silicon, which is why it is also known as Sima (Silica + Magnesium). The density of the mantle varies from 3.1 to 5.1.

It is primarily composed of silicate minerals rich in magnesium and iron, known as ultramafic minerals. The mantle is divided into two main regions: the upper mantle and the lower mantle. The upper mantle is further divided into two parts: the asthenosphere and the lithosphere. The asthenosphere is a partially molten and ductile region located just beneath the lithosphere. It is responsible for the movement of tectonic plates due to its ability to flow slowly over long periods of time. It is within the mantle that magma, the molten rock material, is generated. During volcanic eruptions, magma rises to the surface, serving as the primary source of volcanic activity. The lithosphere, on the other hand, is the rigid outermost layer of the Earth, consisting of the crust and the uppermost part of the mantle. It is broken into several tectonic plates that float on the semi-fluid asthenosphere.

The Earth's crust is the outermost layer of the lithosphere and is the thinnest layer, ranging from 5 to 70 kilometers in thickness. Surrounding the mantle, the crust, and the uppermost part of the mantle together form the lithosphere. The density of the lithosphere ranges between 2.75 and 2.90. The main constituent elements of this layer are silica and aluminum, which is why it is also called Sial (Silica + Aluminum). While parts of the Earth's crust are submerged beneath oceans and seas, forming the hydrosphere, the Earth is also enveloped by a layer of gases that make up the atmosphere, extending skyward for over fifteen miles.There are two types of crust: continental crust and oceanic crust. The continental crust is primarily composed of granitic rocks rich in silica and aluminum, while the oceanic crust is mainly composed of basaltic rocks rich in iron and magnesium. The composition and thickness of the crust vary across different regions of the Earth.

It is important to note that our understanding of the Earth's interior structure is based on various scientific disciplines, including seismology, mineralogy, and geochemistry. Seismic waves generated by earthquakes provide valuable information about the Earth's internal structure and the behavior of different layers. Additionally, studies of rock samples, both from the Earth's surface and deep drilling projects, contribute to our understanding of the composition and properties of the Earth's interior.

While the presented information provides an overview of the Earth's interior structure, it is worth mentioning that scientific research in this field is ongoing. Advances in technology and ongoing exploration missions contribute to the continuous refinement and deepening of our understanding of the complex and dynamic nature of the Earth's interior.