【英语时差8,16】地质活动引发地震和火山喷发（在线收听）

The idea of plate tectonics explains volcanoes as well as earthquakes. Many of the world's volcanoes are found at the edges of plates, where geologic activity is intense. The large number of volcanoes around the Pacific plate has earned the name "Ring of Fire." Volcanoes also are found in the middle of plates, where there is a well of melted rock. Scientists call these wells "hot spots." A hot spot does not move. However, as the plate moves over it, a line of volcanoes is formed. The Hawaiian Islands were created in the middle of the Pacific Ocean as the plate moved slowly over a hot spot. This process is continuing, as the plate continues to move. Volcanoes and earthquakes are among the most frightening events that nature can produce. The earthquake in the Iranian city of Bam at the end of two-thousand-three, for example, killed more than forty-thousand people. At times like these, we remember that the ground is not as solid and unchanging as people might like to think.