Investigating Plate Tectonics, Earthquakes, and Volcanoes

Investigating Plate Tectonics, Earthquakes, and Volcanoes — page 5
PLATE TECTONICs The modern of the theory motions of Earth's outer layers is called plate tectonics It provides a framework for understanding many of Earth's features such as mountains earthquakes and vol canoes as well as the distribution of fossils and the ages of rocks It also helps scientists reconstruct ancient climates and continental configurations BASICS OF THE THEORY In 1912 the German meteorologist Alfred Wegener proposed that the continents had once been joined as a gigantic land mass called Pangea also spelled Pangaea According to this theory called continen tal drift the supercontinent long ago broke into pieces the present continents which have since drifted to their current posi tions At the time many geologists rejected Wegener s ideas partly because he had no convincing explanation why continents would move Io