Directorios

Enlace: http://www.pbs.org/wnet/savageearth/

Descripción: PBS Online.
«Although it feels solid and hard beneath our feet, the outer surface of the Earth is a thin crust of fragile rock, fractured like the cracked shell of an egg. The pieces of the shell are Earth's tectonic plates -- there are 12 major ones -- and they float across a layer of soft rock like rafts in a stream, their motions driven by forces generated deep in the Earth. At their boundaries, the plates spread apart, converge, and slide past one another.»