Why the Earth Quakes Author:Julian May Earthquakes occur every year, all over the world. These dramatic and unexpected happenings arouse the curiosity of everyone, young and old. Just what happens in the earth and why? In this boo the answers of modern geology is given - the theory of the currents in the earth's liquid mantle, which has superseded the discarded hypothesis of quakes' ... more »resulting from shrinkage of the earth. The mantle concept,« less