【英语时差8,16】地幔（下）（在线收听）

Now, however, with the help of sophisticated computers, scientists have discovered what seem to be superplumes, more intense thunderstorms, if you will. The computers produced 3D images of the mantle that suggest the existence of a superplume under Africa and possibly another one under the Pacific. Some scientists suggest that these superplumes may be responsible for the strange shape of the Hawaii-Emperor seamount chain on the floor of the Pacific Ocean. This long chain of undersea mountains, formed over time as the crust moved across a hot spot in the mantle, makes a sharp 45 degree turn around Midway Island. The scientists propose that these superplumes may be responsible for pushing the crustal plates almost to the point of making them reverse directions.