xPlate tectonics : The theory supported by a wide range of evidence that considers the Earth's crust and upper mantle to be composed of several large, thin, relatively rigid plates that move relative to one another.
A magnitude-8.1 earthquake and tsunami that killed 192 people last year in Samoa, American Samoa and Tonga was in fact a triple-whammy. The 8.1 "great earthquake" concealed and triggered two...Read more