The Moon and Earth-quake

摘要

The combined gravitational pull of the Moon and the Sun has effect not only on the water of the seas and oceans, but also on the intercontinental plates of the Earth. The former causes tides, which are regular phenomenon, but the later may cause Earthquakes sometimes, by making displacement of plate/plales depending on the intensity of the said combined gravitational pull, which varies according to the relative positions of the Moon, the Sun and the Earth. Our nearest neighbour in space is Moon. It is at an average distance of 3,84,401 kilometres from the Earth. Its mass is 7.35 × 10~(25)grams (0.0123E). The gravity at its surface is one-sixth as strong as that on the Earth. The Moon travels around the Earth once in about 271/3 days in an elliptical orbit. When the Moon is nearest to the Earth, the position is called, 'Perigee' and when it is farthest away, the position is called , 'Apogee'.