Earth has a mass weighing 59,760 billion tons, with a surface area of 510 million square kilometers. The density of the Earth (about 5,500 kilograms per cubic meter) is used as the unit of weight ratio of other types of planets, the gravity of Earth is set as 1. Earth has a diameter of over 12 756 kilometers. Earth's gravity was measured as 10 N kg-1 used as a unit the size of the gravity of other planets, the Earth's gravity is set as 1.
The structure of planet Earth consists of 3 (three) main layers, namely Barysphere or centrosphere (core), Mesosphere, or mantle (sheath) or Chalkosphere, and lithosphere.
A. Barysphere or Centrosphere (The Earth)
Barysphere or Centrosphere (The Earth) has a radius of ± 3475 km and consists of the elements iron (Fe) and nickel (Ni), so it is often called the Ni-Fe layers. The core is divided into 2 (two), namely:
a) in the dense core, composed of crystalline iron or iron-nickel crystals, fingers ± ± 1,200 km with a temperature of 4800 ° C.
b) the outer core in the form of highly-viscous liquids, the thickness ± ± 2250 km with a temperature of 3900 ° C.
B. MESOSPHERE or Mantel
Mesosphere or mantle is the layer that envelops the earth's core, because it's called the mantle, which means sheath. This layer is a layer between the lithosphere and the core, because it is also called Mesosphere. Thickness ± ± 2900 km with a temperature of 1500 ° C - 3000 ° C, composed of rocks containing oxide and sulfide scales. Because the content of this chemical, called Chalkosphere. The coat consists of inner and outer coat coat. On the outer sheath bordering the lithosphere there is a layer called the asthenosphere liquid.
Among those layers are not continuous with the layers (discontinu), namely:
• Mohorovivic Discontinuity (or Moho layer also called M-Discontinuity). This layer is to limit the Earth's crust (crust) with the upper mantle at depths of 35-60 km +. Was first put forward by A. Andrija Mohorovivic (1857-1936) in 1909. Seismic wave velocity increases after passing through this layer.
• Gutenberg Discontinuity. This layer was found by Beno Gutenberg, limits to the outer core and mantle lies at a depth of 2900 + km.
C. Lithosphere
Lithosphere is derived from the Lithos (= rock) and the sphere or sphaira (= layer), is wrapped around the outside of the Earth. Lithosphere consists of a relatively lighter rock (light rock) than the asthenosphere and the mesosphere. Most of the chemical elements are Silicate (SiO2) which is a mixture of oxygen and silicon. Unsusr other chemical elements are oxygen (46.6%), silicon (27.7%), aluminum (8.1%), iron (5%), calcium (3.6%), sodium (2.8% ), potassium (2.6%), and magnesium (2.1%).
Lithosphere layer is a layer of very thin, dense, hard, strong, and the most rigid, yet elastic (springy) among all layers of the Earth, because it is called the crust (crust). This crust forms occur because of differences in temperature (temperature amplitude) are great between asthenosphere layer which can reach> 10000 C with a face of the Earth. About 100 km thick lithosphere, including the earth's crust and upper mantle layer. other than as a place to stand, move, and plant growth media, the lithosphere is a vehicle mines and mineral materials.
According to the theory of plate tectonics (Tectonic plate theory), the lithosphere consists of plates of each pair, so it resembles Earth-tide loading games (puzzles). The plates continuously move away from each other or each slide or grind each other, resulting in an uneven shape Earth. Lithospheric plates are divided into two kinds, namely the continental shelf and oceanic plates.
Continental plate is a plate that is not submerged sea water and on it stood the continents with an average thickness of ± 30 km and in mountainous areas ± 70 km. These plates are subdivided into 3 (three) layers:
The top layer with a thickness of + 15 km (type granite magma), the main chemical elements silicium and aluminum;
• The thick middle layer + 25 km (type basaltic magma), the main chemical elements silicium and aluminum; and
• The bottom layer thickness + 20 km (type peridotite magma and eklogit), the main chemical elements silicium and magnesium.
Plates meet the oceanic lithosphere ± 65%. The main chemical elements are silicium and magnesium, so-called Ma-Si layer, its thickness at the bottom of the ocean reaching ± 6 km.
continental crust
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oceanic crust
|
layer called the si-al (aluminum silisium)
| called ma si-layer (silisium magnesium) |
contains elements of aluminum in large quantities
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contains elements of magnesium in large quantities
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composed of very old rocks that are granitis
| consisting of rock basaltis younger are more dense than continental crust |
the main elements forming the aluminum-rich silicate minerals, potassium, and sodium
| its main constituent elements of silicate minerals which are rich in magnesium, iron, calcium, and a little aluminu |
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