AN EXTENDED MASS OF ICE FORMED FROM SNOW FALLING AND ACCUMULATING OVER THE YEARS AND MOVING VERY SLOWLY, EITHER DESCENDING FROM HIGH MOUNTAINS, AS IN VALLEY GLACIERS, OR MOVING OUTWARD FROM CENTERS OF ACCUMULATION, AS IN CONTINENTAL GLACIERS.
A part of a body of water along the shore deep enough for anchoring a ship and so situated with respect to coastal features, whether natural or artificial, as to provide protection from winds, waves, and currents.
A usually triangular mass of sediment, especially silt and sand, deposited at the mouth of a river. Deltas form when a river flows into a body of standing water, such as a sea or lake, and deposits large quantities of sediment. They are usually crossed by numerous streams and channels and have exposed as well as submerged areas.
A REGION SO ARID BECAUSE OF LITTLE RAINFALL THAT IT SUPPORTS ONLY SPARSE AND WIDELY SPACED VEGETATION OR NO VEGETATION AT ALL: THE SAHARA IS A VAST SANDY DESERT.
A land formation, less extensive than a plateau, having steep walls and a relatively flat top and common in arid and semiarid parts of the southwestern U.S. and Mexico.
a natural elevation of the earth's surface rising more or less abruptly to a summit, and attaining an altitude greater than that of a hill, usually greater than 2000 feet (610 meters).
A VENT IN THE EARTH'S CRUST THROUGH WHICH LAVA,STEAM,ASHES,ETC.,AREEXPELLED,EITHERCONTINUOUSLY OR AT IRREGULAR INTERVALS.A MOUNTAIN OR HILL, USUALLY HAVING A CUPLIKE CRATER AT THE SUMMIT, FORMED AROUND SUCH A VENT FROM THE ASH AND LAVA EXPELLED THROUGH IT.