10.3 Magnetic Earth Flashcards
What is the shape of the Earth’s Magnetic Field?
A compass needle points north due to its small magnet, which aligns with the Earth’s magnetic field. This force is exerted on the needle, pointing to the Earth’s magnetic pole. The magnetic north pole is located in Canada, about 400 km away from the geographic North Pole. The pole moves at a rate of 30 km a year from Canada to Russia. The Earth’s geographic North Pole is at the top of its axis of rotation.
Why is there a magnetic field around the Earth?
Earth behaves as if there is a huge bar magnet inside it. The magnetic field pattern is like that of a bar magnet. If a compass needle points north, then the South Pole of the earth magnet must be in the north. There is no bar magnet inside the earth and scientists think that the outer core of earth is made of iron that can move. This produces a magnetic field like current flowing in a while. However, scientists are not sure why the magnetic North Pole moves as it does. On the Earth magnetic field lines, they go from south to north.
Why is the Earth’s magnetic field important?
If the Earth did not have a magnetic field, then there would be no life alone. The magnetic field protects the Earth. The sun emits radiation in the direction of the Earth, which is called solar wind. It is not the sort of wind that you feel when wind moves around you. It is made of electrically charged particles that can damage or kill cells, so all living organisms would die. The Earth’s magnetic field deflects the solar wind, so most of it does not reach the surface of the Earth. Not all the solar wind is reflected, however. Some of it can reach the atmosphere at the northern South poles. This produces Aurora, dramatic lights in the sky, called the Northern and Southern Lights.
