The Earth

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Do you know ? …..Lampang and Phrae Provinces

used to be the Sea?

-Why is it so?-What cause that effect on the Earth ?-What is the evidence that the Geologist use to conclude ?

student must to understand more So, you should study about

1. Beginning and structure of the Earth

2. Change of the Earth

1.Beginning of the Earth Earth began to form

over 4.6 billion years ago from the same cloud of gas (mostly hydrogen and helium) and interstellar dust that formed our sun. During this process, the remaining clouds of gas and dust that surrounded the sun began to form into smaller lumps called planetesimals, which eventually formed into the planets we know today.

2.How to study the structure of the Earth. Scientists have tried to use various methods to study the structure of the Earth, both directly and indirectly. Because no technology that can collect samples and to measure the depth of the lot is

Methods for studying the structure is as follows.

A. Sir Isaacs Newton discovered the value of  the average density was estimated to be 2 times the density of rocks on the Earth's surface. Show the earth that contain chemicals that are denser than the Earth's surface.

B. Explore a variety of explosive volcanoes.

 This indicates that some of the world, with heat and pressure to the molten rock.  Along with the temperature in deep mines and drill the  holes. It was found that the temperature rise 

within the depths of the earth's surface.

C. Study of the inspection Of Ofhiolite. The study of volcanic rocks. The chemical composition of meteorites that fell on the earth and rock samples

 from the moon

D. Study of seismic waves caused by earthquakes. Wave of man-made (nuclear) 

and measuring the force of gravity on the earth's surface.

Study the structure of the earth by Seismic wave

Seismic waves are waves of energy that travel through the earth . There are 2 types , body wave and surface wave

Body waves travel through the interior of the Earth ,as

Primary waves (P waves) and Secondary waves (S waves)

1. Primary waves, P waves that travel faster than other and travel through any type of material.

2. Secondary waves, S waves can travel only through solids

When seismic waves travel through the interior

of the Earth, they refracted or reflected of

the earth’s interior. The density and modulus,

vary according to temperature, composition and phase. So that we can conclude the structure of

the earth.

3. Classify the structure of the earth

classify by type of mass or physical and chemical property of rock

1. Crust

2. Mantle

3. Core

1. Crust

As the outer skin that covers the world. Is divided into two areas.

1.continental crust

Means that the whole earth. 

Both continents and the continental shelf.

The average thickness of 35-40 km, some of the more than 70 kilometers, most of the elements silicon and aluminum. 

Sometimes called the SIAl

2. Oceanic crust The crust of the ocean was covered with water.

 Most of the elements silicon and magnesium. 

Sometimes called the SIMA.

has a thickness of about 5 to 10 kilometers.

Boundary between the crust and mantle.

or The Mohorovicic discontinuity. 

( MoHo).

Study of rocks in the lower part of the Orhyolite 

and a rock that is found near the Earth's oceans.

It is divided by a cumulate ultramafic rocks and

non-cumulate ultramafic rocks.

2. Mantle

A thick layer beneath the crust is 

almost solid. 

The depth of the bottom of the crust 

to the upper part of the Earth is about 2,900 kilometers.

- Upper mantle

is a stone cold the next. Igneousrock, which is ultramafic. And some are brittle and cracked.

Upper mantle layer and the crust together referred to as lithosphere.

The  lithosphere is the depth from the surface to a depth of 100 km.

- Lower mantle

layer of molten rock or magma,

which is inside the circle slowly. 

Depths ranging from 350-2900 kilometers,

Temperatures will rise from about 2250 to about 4500 degrees C, 

The mantle and the lower support plate 

are the asthenosphere.

3. Core

The depth of around 2,900 kilometers 

from the surface down to about 80%  iron, which contains the remaining elements are nickel, oxygen and sulfur.

Divided into two parts.

- Outer core : is believed to consist of a hot  solution 

of  ferrous and nickel.  And the  very hot down

to a depth of about 5,000 km.

- Inner core : components like the outer layer.

 But in the solid state due to high pressure 

and high temperature may be as high as 6,000degrees C.