THE EARTH CRUST
Well our Earth take million year to make a perfect place to live. About 2500 million years ago (according to present theories), the earth on which we live was a ball of gas which, on cooling, grew smaller and became liquid. The liquid continued to cool, giving off some of its heat by radiation. When liquid grow colder, they solidify. The crust of the earth is the solid matter resulting from this cooling, but probaly inside the earth, there is still a mass of molter malten material which has not cooled as much as the outer crust.
The crust on which we live and from which we obtain almost everything that we have is not quite rigid. Volcanoes present on etna and stromboli in italian islands remind us from time to time of the force and heat below the ground. Various places on the earth are subject to earthquakes, the country that has suffered most from these being japan.
The study of earthquike, the science of seismology, has shown that the origin of many of them is under the bottom of the sea and near the coast of a continent or large island. In an earthquake, the surface of the land may move suddenly in any direction, bringing houses down, changing the shapes of hills, and sometime causing an immense sea wave to rush on to the nearest shore and add to the destruction
The study of earthquike, the science of seismology, has shown that the origin of many of them is under the bottom of the sea and near the coast of a continent or large island. In an earthquake, the surface of the land may move suddenly in any direction, bringing houses down, changing the shapes of hills, and sometime causing an immense sea wave to rush on to the nearest shore and add to the destruction
Comments
Post a Comment