The term "United States," when used in the geographical sense, refers to the contiguous United States, the state of Alaska, the island state of Hawaii, the five insular territories of Puerto Rico, Northern Mariana Islands, U.S. Virgin Islands, Guam, and American Samoa, and minor outlying possessions. The United States shares land borders with Canada and Mexico and maritime borders with Russia, Cuba, The Bahamas, and many other countries, mainly in the Caribbeanin addition to Canada and Mexico. The northern border of the United States with Canada is the world's longest bi-national land border.
The Tethys Ocean, also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents of Gondwana and Laurasia, before the opening of the Indian and Atlantic oceans during the Cretaceous Period.
In the context of physical geography, the Intermontane Plateaus is one of eight physiographic regions of the contiguous United States. The region consists mostly of plateaus and mountain ranges lying between the Rocky Mountains on the east and the Cascade and Sierra Nevada Mountains on the west. It is subdivided into three physiographic provinces: the Columbia Plateau in the north, the Basin and Range Province in the central and southwestern portions, and the Colorado Plateau in the southeast. In turn, each of these provinces are each subdivided into a number of physiographic sections.
The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins. The physiography of the province is the result of tectonic extension that began around 17 million years ago in the early Miocene epoch.
The richly textured landscape of the United States is a product of the dueling forces of plate tectonics, weathering and erosion. Over the 4.5 billion-year history of the Earth, tectonic upheavals and colliding plates have raised great mountain ranges while the forces of erosion and weathering worked to tear them down. Even after many millions of years, records of Earth's great upheavals remain imprinted as textural variations and surface patterns that define distinctive landscapes or provinces.
The Interior Plateau comprises a large region of the Interior of British Columbia, and lies between the Cariboo and Monashee Mountains on the east, and the Hazelton Mountains, Coast Mountains and Cascade Range on the west. The continuation of the plateau into the United States is known there as the Columbia Plateau.
The North American Cordillera, sometimes also called the Western Cordillera of North America, the Western Cordillera or the Pacific Cordillera, is the North American portion of the American Cordillera, the mountain chain system (cordillera) along the western coast of the Americas. The North American Cordillera covers an extensive area of mountain ranges, intermontane basins and plateaus in Western/Northwestern Canada, Western United States and Mexico, including much of the territory west of the Great Plains.
The Intermountain West, or Intermountain Region, is a geographic and geological region of the Western United States. It is located between the front ranges of the Rocky Mountains on the east and the Cascade Range and Sierra Nevada on the west.
The Intermontane Plate was an ancient oceanic tectonic plate that lay on the west coast of North America about 195 million years ago. The Intermontane Plate was surrounded by a chain of volcanic islands called the Intermontane Islands, which had been accumulating as a volcanic chain in the Pacific Ocean since the Triassic period, beginning around 245 million years ago. The volcanism records yet another subduction zone. Beneath the far edge of the Intermontane microplate, another plate called the Insular Plate was sinking. This arrangement with two parallel subduction zones is unusual. The modern Philippine Islands are located on the Philippine Mobile Belt, one of the few places on Earth where twin subduction zones exist today. Geologists call the ocean between the Intermontane islands and North America the Slide Mountain Ocean. The name comes from the Slide Mountain Terrane, a region made of rocks from the floor of the ancient ocean.
North America is the third largest continent, and is also a portion of the third largest supercontinent if North and South America are combined into the Americas and Africa, Europe, and Asia are considered to be part of one supercontinent called Afro-Eurasia. With an estimated population of 580 million and an area of 24,709,000 km2 (9,540,000 mi2), the northernmost of the two continents of the Western Hemisphere is bounded by the Pacific Ocean on the west; the Atlantic Ocean on the east; the Caribbean Sea on the south; and the Arctic Ocean on the north.
The Slide Mountain Ocean was an ancient ocean that existed between the Intermontane Islands and North America beginning around 245 million years ago in the Triassic period. It is named after the Slide Mountain Terrane, which is composed of rocks from the ancient oceanic floor. There was a subduction zone on the Slide Mountain Ocean's floor called the Intermontane Trench where the Intermontane Plate was being subducted under North America. The floor of the Slide Mountain Ocean was pushed up onto the ancient margin of North America.
The Intermontane Trench was an ancient oceanic trench during the Triassic. The trench was probably 600 to 800 miles long, parallel to the west coast of North America. The ocean that the trench was located in was called the Slide Mountain Ocean.
The Cassiar Mountains are the most northerly group of the Northern Interior Mountains in the Canadian province of British Columbia and also extend slightly into the southernmost Yukon Territory. They lie north and west of the Omineca Mountains, west of the northernmost Rockies and the Rocky Mountain Trench, north of the Hazelton Mountains and east of the Boundary Ranges. They form a section of the Continental Divide, that, in this region, separates water drainage between the Arctic and Pacific Oceans. Physiographically, they are a section of the larger Yukon-Tanana Uplands province, which in turn are part of the larger Intermontane Plateaus physiographic division.
The Intermontane Belt is a physiogeological region in the Pacific Northwest of North America, stretching from northern Washington into British Columbia, Yukon, and Alaska. It comprises rolling hills, high plateaus and deeply cut valleys. The rocks in the belt have very little similarities with the North American continent.
The Central Mexican Plateau, also known as the Mexican Altiplano, is a large arid-to-semiarid plateau that occupies much of northern and central Mexico. Averaging 1,825 m (5,988 ft) above sea level, it extends from the United States border in the north to the Trans-Mexican Volcanic Belt in the south, and is bounded by the Sierra Madre Occidental and Sierra Madre Oriental to the west and east, respectively.
The following outline is provided as an overview of and introduction to Oceanography.
This is a list of articles related to plate tectonics and tectonic plates.
The Sayan intermontane steppe ecoregion is sometimes referred to as a "steppe island", being an expanse of grassland and shrubs surrounded by mountain forests in the Tyva Republic of south central Siberia, Russia. The Altai Mountains are to the west, the Sayan Mountains to the north, and the Tannu-Ola Mountains to the south. The ecoregion is in the temperate grasslands, savannas, and shrublands biome, and the Palearctic realm, with a Humid Continental climate. For much of its length, it follows the course of the upper Yenisei River. It covers 33,928 km2 (13,100 sq mi).
