国家地理自然力量

　　Volcanoes, earthquakes, and tornadoes all can cause enormous damage, and predicting where and when they will strike is of great importance. Volcanologist Dr. Marie Edmonds has devised sensors that monitor the underground activity of magma to better predict future eruptions on the Caribbean island of Monserrat, the site of the massive 1995 eruption captured for this film. Geophysicist Dr. Ross Stein studied the earthquake repair records in Istanbul's Hagia Sophia over the centuries to find