History | As the Earth's Magnetic Field Shielding

When we asked about what layer that protects the earth, surely the answer is a layer of the atmosphere. Answers like that are often the authors encountered from students and teachers bahka. However, the response of the atmosphere as the Earth's protective layer is certainly not wrong but the atmosphere was not alone, there are friends of the earth's magnetic field whose job is to protect people from the threat of cosmic radiation from outer space. How can the Earth has a magnetic field and how magnetic fields have protected creature on earth along, let us read the following discussion of the author.

Earth's Magnetic Field

In 1830 to 1842, Karl Frederick Gauss detailed observations of the Earth's magnetic field. He concluded that the Earth's magnetic field comes from the earth. He also stated that the Earth's magnetic field also has a close relationship with the rotation of the earth because the earth's magnetic poles close to the Earth's spin axis (Telford, 1990).

The magnetic field of the Earth's core is generated due to the Earth's core formed of iron and nickel. In theory proposed by WM magnetohidrodinamik Elasasser and E.C. Bullard, stated that in the outer core of the earth there is a stream of ionized fluid causing the dynamo action by itself (Self-exiting dynamo action), which can cause major magnetic field

Earth's Magnetic Field

Earth (Lucky, 2001). When there is a current that surrounds an iron rod of iron will become magnetic. For simple experiments comrades should wrap electrical wire on a nail, then the stream of electric current that comes from the battery then it will be the nail bar magnet. Similarly, the Earth's core consists of iron and nickel into Earth's magnetic field or a giant bar magnet.

In the next picture can be seen that the magnetic field is different from the geographic poles of the earth. Earth's magnetic north pole is on the south pole of Earth's geographic south pole while the Earth's magnetic field is at the north pole of the earth. So it is natural that our magnetic north compass will point to the south pole of the magnetic field in Earth's geographic north pole. But we do not exactly compass facing north because of the geography of the earth there lies the difference with the axis of Earth's northern axis magnetic south pole. Difference or deviation angle between both of them is called the declination angle. For the Banda Aceh region around -1 ° declination angle. For the angle of the Earth's magnetic field is also known as the angle of inclination. For Banda Aceh, the angle of inclination about - 5 ° 34 ', this means that if we are facing north towards the Earth's magnetic field will penetrate our body from behind with a slope of - 5.5 ° toward the top of the plane. For readers who want to know the value of magnetic intensity and its declination and inclination angle in each city can click here.

In addition to the Earth's magnetic field axis moves around a lot. In the history of the earth has happened a few times where the reversal of the Earth's north pole becomes the south and south to north. Since 160 million years ago has happened hundreds of times a magnetic pole reversal. Although it has happened hundreds of times, this magnetic pole reversal does not show a specific pattern of repetition so it is difficult to predict when the magnetic poles will reverse again. So the issue of the end of 2012 due to the reversal of Earth's magnetic field is a whopper. Image reversal of the magnetic poles since 160 million years ago can be seen in the picture.

Earth Shield

In 1927, Jacob Clay serorang Dutch scientists found evidence that the primary cosmic radiation influenced by the Earth's magnetic field. In air travel to Indonesia, he found that the intensity of cosmic radiation is reduced when approaching the equator of the Earth's magnetic field.

Earth's magnetic field from the earth stretched up to far into space. The magnetic field forms an invisible shield called the magnetosphere. This shield protects us from cosmic radiation and the enormity of the dangers that come from the Sun. These dangers include solar storm (in the form of a continuous flow of electrically charged particles), the explosion of the Sun (which in a few minutes can release energy equivalent to billions of hydrogen bombs), and hurling mass of the corona / coronal mass ejections.

The lines of magnetic force of the earth that stretches far into space, capturing charged particles moving encircling lines of magnetic force. Because these lines are the most polar region, then the area is electrically charged particles to penetrate into Earth's atmosphere and causing a natural performances called the northern lights or aurora (Mukhlis Akhadi and Hasnel Sofyan, 1999). So the formation of the aurora in the north and south poles due to the refraction of cosmic radiation by the magnetosphere.