UNDERSTANDING OUR PLANET Q/A - What facts make it probable that Earth’s core is composed of mostly iron? - The analogy for this fact is big magnet theory. The magnetic field of the Earth is more or less like that would be produced if there were a giant bar magnet at the center of the Earth. This assumption is obtained according to the fact that the earth is dynamic. Pressure and movement attached to metal (iron) will make a magnetic power to such metal. Since the earth have a magnetic field (gravitation), it is assumed that beneath the earth must be metal material. In this case, the most powerful metal to be given a magnetic power is iron.
The Earth's field sometimes switches polarity and compasses would point South. This happened last about 780,000 years ago and could happen again any millenia now. These facts confirm the existence of a fluid outer core made of pure metal. It is the motions in...
UNDERSTANDING OUR PLANET Q/A #3 - What would Earth be like without solar heating? - The life is impossible to find. There will be no existence of life in this world since all of the processes of living creatures need solar heat for their “fuel”. Plant produces food storage in their body tissues by photosynthesis which needs radiation from sunlight. On the other hand, solar heating also influence physical processes in the Earth. The Earth would probably not be fit for life. Hydrological cycle needs Sun radiation as trigger. Radiation heats the atmosphere. Therefore, unequal condition of atmospheric pressure will occur. This will move the air. From this point, weather will be influenced. Without the Sun, Earth would be an icy rock in space....
UNDERSTANDING OUR PLANET Q/A #2- Why doesn’t Earth keep getting larger if the rocks is continually created? - The concept of rock creation is similar as a cycle. The rocks that are formed on the outside of the earth come from the inside of the earth. Therefore, when rocks are formed on the outside of the earth, they leave empty spaces inside the earth. In reality, the "empty space inside" that I mentioned could be very small and is not deep in the earth's crust. Rocks are formed from lava (igneous rocks) or from part of the earth's crust (sedimentary rocks).Rocks are created at rift zones in the crust--they are also plowed into the mantle at subduction zones and melt.They don't add any weight to the earth because when the weight of the rocks is added to the weight of the rest of the earth, the total weight is the same as it was before the rocks were formed.
Generally saying,...
