Friday, 25 March 2011
CASE 242 - Earths Core
The inner part of the earth is the core. This part of the earth is about 1,800 miles (2,900 km) below the earth's surface. The core is a dense ball of the elements iron and nickel. It is divided into two layers, the inner core and the outer core. The inner core - the center of earth - is solid and about 780 miles (1,250 km ) thick. The outer core is so hot that the metal is always molten, but the inner core pressures are so great that it cannot melt, even though temperatures there reach 6700ºF (3700ºC). The outer core is about 1,370 miles (2,200 km) thick. Because the earth rotates, the outer core spins around the inner core and that causes the earth's magnetism.
What does the core consist of?
It is 3,200 - 3,960 miles (5,150-6,370 km) below the earth's surface and mainly consists of iron, nickel and some lighter elements (probably sulphur, carbon, oxygen, silicon and potassium. The temperature in the inner core is about 9032 - 10832 ºF (5000-6000 ºC). Because of the high pressure, the core is solid. The average density of the core is about 15g/cm³.
The outer core is at 1,800 - 3,200 miles (2,890-5,150 km) below the earth's surface. The outer core is liquid and mainly consists of iron, some nickel and about 10% sulphur and oxygen. The temperature in the outer core is about 7200 - 9032 ºF (4000-5000ºC). The density of the outer core is between the 10g/cm³ and 12,3g/cm³. The outer core and inner core together cause the earth's magnetism.
What Influence does the Core have?
Because the core is so hot, it radiates a natural heat to the upper layers. Because of this a current of heat comes into being. Those are also known as the convection currents. The convection currents cause the movement of the tectonic plates. This movement is called plate tectonics. The outer core and the inner core together cause the earth's magnetism. Because the earth rotates, the outer core spins, the inner core doesn't spin because it's solid. This gives a kind of dynamo effect and causes the earth's magnetism. Magnetism has been used by sailors to find their way on earth for thousands and thousands of years. Magnetism also influences electro-particles outside the atmosphere of the earth, up to more than 37,000 miles (60,000 km) into space