U.S. Geography

U.S. Geography

North America

The surface of the USA can be divided into five main geographical areas. To the east and southeast, the broad Coastal Plain stretches along the Atlantic and Gulf of Mexico coasts. The Appalachian Mountains run parallel to the east coast. West of them, the central plain turns into a prairie plateau. The entire western half of the USA is filled by the Cordillera mountain range. Their western branch along the Pacific coast and the Rocky Mountains to the east enclose a landscape of plateaus, basins and mountain ranges.

According to allunitconverters, the Coastal Plain begins in the northeastern United States with the Cape Cod Peninsula in Massachusetts. It is quite narrow in this part, and Long Island in the state of New York also belongs to it. It stretches south across the marshy Delaware Peninsula and expands to more than 200 km in Virginia. It follows the grade of the Piedmont and reaches its greatest extent in the south in Georgia. Almost along the entire 1,700 km long east coast, a series of islands stretches like a breakwater. The sea in this area flooded the numerous river valleys at the mouths, creating deeply incised bays such as the Delaware and Chesapeake Bays with the Potomac, Pamlico Sound and others. The low-lying and marshy Florida peninsula in the south was created by the uplift of part of the coastal continental shelf. In the south, the Atlantic Plain passes into the Mississippi Plain, which extends north to the confluence with the Ohio. It extends into the Gulf of Mexico in an extensive delta, which the alluvium moves further into the sea every year.

The 3,000 km long Appalachian Mountains run parallel to the Atlantic Coastal Plain from Canada to northeastern Alabama. In the north it is divided into several belts (the highest are the White Mountains, 1917 m) with numerous glacial lakes, in Pennsylvania it expands into a vast plateau. The Appalachians proper form a system of parallel, long, rounded ridges with almost no transverse valleys. Formerly heavily agricultural, the rolling Piedmont in the southeast rises high above the long ridge of the Blue Ridge Mountains, with its highest mountain , Mount Mitchell(2,037 m) in North Carolina. West of the main range lies the Great Appalachian Valley cut by the Tennessee River and its tributaries. Beyond it lies the Cumberland Plateau, which merges into the Allegheny Mountains to the northeast.

The center of the USA is occupied by the vast basin of the Central Plains (plains), up to 2,500 km wide. To the north, in the Great Lakes region, the outcrops of the Canadian Shield highlands reach 600–700 m around Lake Superior. To the south, the basin descends and passes into the Mississippi Plain. The entire vast area is drained by the Mississippi-Missouri River and the Ohio. In the east, the plains are bordered by the Kentucky and Tennessee plateaus, in the west, the Ozark Plateau and Ouachita Mts rise in Missouri and Arkansas. Further west, the lowlands transition into the dry to semi-desert region of the Great Plains or prairies (Great Plains), above which the Rocky Mountains rise sharply.

The Cordillera mountain system covers almost half of the US territory. It consists of two main mountain ranges that stretch from Canada south to Mexico. More massive, up to 600 km wide, are the Rocky Mountains in the east, reaching the highest heights in Colorado (Mt. Elbert 4399 m). The larger area is filled by plateaus and basins such as the Wyoming, which is the main pass through the Rocky Mountains and through which the trails of the first pioneers once led, as well as highways now. The nearby Yellowstone and Grand Teton National Parks represent the most beautiful natural scenery in the USA. Also in southern New Mexico, plateaus are dominant, divided by the Rio Grande and Pecos rivers, and passing to the southeast into the Llano Estacado semi-desert.

Vast basins and plateaus lie west of the Rocky Mountains. To the north, vast lava plateaus cut by the Columbia and Snake rivers surround the fertile Columbia Basin, located mostly in Washington state. Further to the south, large mountain depressions spread out, mainly dry basins without drainage separated by relatively low mountain ridges. The largest of these is the Great Basin, covering most of Nevada. At its northeastern end in the state of Utah lies the Great Salt Lake. To the south, mainly on the territory of Arizona, lies the Colorado Plateau, cut through a length of 350 km by the world’s deepest canyon (up to 1,800 m) of the Colorado River. Grand Canyon National Parkit is complemented in this area by a number of other national parks with numerous bizarre formations of table mountains, rock towers and canyons created by erosion.

The Western Cordillera range has two main branches. The Coast Ranges stretch from the glacial mountains of the Olympia Peninsula in the north to Los Angeles in the south. The higher, eastern range consists of the Cascade Range in the north and the Sierra Nevada in the south. Between them are valleys that begin in the north at Puget Sound, continue through the Willamette River Valley in Oregon, and through the broad Central Valley in California.

The Cascade Range reaches its highest heights with the massif of the glaciated volcano Mt. Rainer (4391 m) in Washington. Not far from it lies the mountain of St. Helena, whose destructive eruption in 1980 is one of the strongest in the world. The range continues in Oregon with another chain of volcanoes to Lassen Peak in northern California. There begins the crystalline Sierra Nevada, cut into individual massifs by a series of river and glacial valleys. The highest mountain is Mount Whitney (4418 m) and the most famous Yosemite National Park with its famous waterfalls. To the southeast lies the depression of Death Valley, the deepest depression in America (86 m below sea level).

Within the Coast Ranges, a system of tectonic faults stretches from northern California to Point Conception, and the entire area is affected by frequent earthquakes. The most famous earthquakes in the San Andreas fault destroyed in 1989 and 1993.

U.S. Geography