Oceanic trench — Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric scale long but narrow topographic depressions of the sea floor. They are also the… … Wikipedia
Slide Mountain Ocean — The Slide Mountain Ocean was an ancient ocean that existed between the Intermontane Islands and North America sometime during the Triassic time beginning around 245 million years ago. The name comes from the Slide Mountain Terrane, a region made… … Wikipedia
United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… … Universalium
North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… … Universalium
North American Cordillera — The North American Cordillera is the North American portion of the American Cordillera which is a cordillera extending up and down the western side of the Americas. The North American Cordillera covers an extensive area of mountain ranges,… … Wikipedia
Physiographische Regionen der Erde nach Fenneman — Die Physiographischen Regionen nach Nevin Fenneman weisen die verschiedenen physiogeographischen (naturräumliche) Einheiten aus, wie sie sich aus geologischen und geomorphologischen Faktoren ergeben. Die Grobeinteilung stellt sich wie folgt dar,… … Deutsch Wikipedia
continental landform — ▪ geology Introduction any conspicuous topographic feature on the largest land areas of the Earth. Familiar examples are mountains (including volcanic (volcanism) cones), plateaus, and valleys. (The term landform also can be applied to… … Universalium
Ocean — For other uses, see Ocean (disambiguation). Maps exhibiting the world s oceanic waters. A continuou … Wikipedia
Volcanic arc — Mariana Islands, an oceanic island arc A volcanic arc is a chain of volcanoes positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an… … Wikipedia
mountain — mountainless, adj. /mown tn/, n. 1. 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 ft. (610 m). 2. a large mass of something… … Universalium
