class 11 geography question
Explain the structure of the earth with the help of
diagram
Answers
Answer:
The structure of the Earth is divided into layers. These layers are both physically and chemically different. The Earth has an outer solid layer called the crust, a highly viscous layer called the mantle, a liquid layer that is the outer part of the core, called the outer core, and a solid center called the inner core. The shape of the earth is an oblate spheroid, because it is slightly flattened at the poles and bulging at the equator.
Earth cutaway diagram. The proportions are not accurate
The boundaries between these layers were discovered by seismographs which showed the way vibrations bounced off the layers during earthquakes. Between the Earth's crust and the mantle is a boundary called the moho. It was the first discovery of a major change in the Earth's structure as one goes deeper.
The crust is the outermost layer of the Earth. It is made of solid rocks. It is mostly made of the lighter elements, silicon, oxygen, aluminium. Because of this, it is known as sial (silicon = Si; aluminium = Al) or felsic.
The mantle is the layer of the Earth right below the crust. It is made mostly of oxygen, silicon and the heavier element magnesium. It is known as sima (Si for silicon + ma for magnesium) or mafic. The mantle itself is divided into layers.
The uppermost part of the mantle is solid, and forms the base of the crust. It is made of the heavy rock peridotite. The continental and oceanic plates include both the crust proper and this uppermost solid layer of the mantle. Together this mass makes up the lithosphere. The lithosphere plates float on the semi-liquid aesthenosphere below.
Upper aesthenosphere: magma
Lower aesthenosphere
Lower mantle
The Earth's core is made of solid iron and nickel, and is at about 5000–6000 °C.
Outer core is a liquid layer below the mantle.
Inner core is the very center of the Earth.[1]
A full explanation of these effects is not yet clear. It seems that the high temperature and pressure cause changes in the crystallization of minerals, so that the composition might be a kind of changing mixture of liquid and crystals.
Answer:
structure of the Earth is divided into three types:
1.The CRUST : it is the outermost solid part of the earth.
it is brittle in nature.
The thickness of The crust varies under the oceanic and Continental area. Oceanic crust is thinner as compared to the continental crust.
The continental crust is thicker in the area of the major mountain system.
The type of the rock found in the ocean is basalt. The mean density of the material is Ocean crust is 2.7 gram per centimetre cube.
2.The MANTLE: the portion of the interior beyond The crust is called mental
It extends from the moho's discontinuity to a depth of 2,900 km.
The upper portion of the Mantle is called asthenosphere .
It is the main source of Magma that find its way to the surface during the volcanic eruption.
The crust and the uppermost part of the Mantle are called lithosphere.
Its thickness is ranges from 10 - 200 km.
the lower Mantle extend beyond the asthenosphere. It is called solid state.
The CORE: the core-mental bond is located at the depth of 2900 km.
The outer core is in the liquid state while the inner core is in the solid state.
The density of the material at the Mantle core boundary is around 5 gram per centimetre cube.
the core is made up of very heavy material mostly constituted by the Nickel and iron.
it is sometimes referred to as the Nife layer (Ni =nickel ; fe= iron)