Category: Dictionary

public land : Any land area held and managed in the public domain by a federal or local government.

Prime Meridian : The imaginary line running from north to south through the Royal Observatory in Greenwich, England which is assigned a longitude of 0 degrees and is therefore used as the reference point for all other lines of longitude.

prevailing winds : The direction from which winds most frequently blow at a specific geographic location

primary sector : That portion of a region’s economy devoted to the extraction of basic materials (e.g., mining, lumbering, agriculture)

presque-isle : A peninsula connected to the mainland by an extremely narrow neck of land such that the land at its distal end is very close to being an island. See also tied island.

Precambrian rock : The oldest rocks, generally more than 600 million years old

prairie : A type of temperate grassland ecosystem dominated by a characteristic composition of grasses, herbs, and shrubs, rather than by trees. The term is used primarily in North America, but similar ecosystems can be found across the world.

pothole: Also called a pot, swirlhole, churn hole, evorsion, rock mill, and eddy mill.

1.  Any smooth, bowl-shaped or cylindrical hollow, generally deeper than it is wide, that is carved into the rocky bed of a watercourse such as a stream or river. Fluvial potholes are created by the grinding action of stones or coarse sediment kept in perpetual motion in the same spot by the turbulence of the current. The term is also used to refer to plunge pools beneath waterfalls, which are created by similar processes. See also kolk.2.  A vertical or steeply inclined karstic shaft in a limestone deposit.3.  In the Great Plains of North America, a shallow depression, generally less than 10 acres (4.0 ha) in area, occurring between dunes or on morainic relief on a prairie and often filled by an intermittent pond or marsh.4.  Another name for a kettle.5.  Another name for a panhole.

post-industrial : An economy that gains its basic character from economic activities developed primarily after manufacturing grew to predominance. Most notable would be quaternary economic patterns.

positioning system : Any technology or mechanism used to determine the position of an object in space. Numerous methods for determining position have been practiced since ancient times, though modern positioning systems generally rely on electromagnetic and/or satellite-based technologies capable of providing coverage ranging from local or regional to global and accuracy ranging from tens of metres to sub-millimetre.

population geography : A branch of human geography that studies the ways in which spatial variations in the composition, distribution, migration, and growth of populations are related to the nature of places. This often involves factors such as where populations are found and how the size and composition of these populations is regulated by the demographic processes of fertility, mortality, and migration.

population : A collection of organisms of the same group or species which live in a particular geographical area. In the context of geography, it often refers to a collection of humans and is represented at the most basic level as the number of people in a given geographically or politically defined space, such as a city, town, region, country, or the entire world.

populated place : A place or area with clustered or scattered buildings and a permanent human population (a city, settlement, town, or village) that is referenced with geographic coordinates

pond : A natural or artificial body of standing water that is usually smaller than a lake.

polynya : An area of unfrozen seawater surrounded by an otherwise contiguous area of pack ice or fast ice. Polynyas are often formed along polar coastlines through the action of katabatic winds, but may also form in the open ocean.

polynodal : Many-centered

political geography : The study of both the spatially uneven outcomes of political processes and the ways in which political processes are themselves affected by spatial structures. A sub-discipline of human geography, its primary concerns can be summarized as the relationships between people, state, and territory.

pole of inaccessibility : A location that, with respect to a given geographical criterion, is the most difficult to reach according to that criterion, e.g. the geographical location that is the most distant from the nearest point meeting that criterion. The term most commonly refers to the so-called continental or oceanic poles of inaccessibility, i.e. the point on a given continental landmass that is the furthest distance from a coastline, and the point in the ocean that is the furthest distance from land, respectively.

polder : A low-lying tract of land enclosed by dikes, forming an artificial hydrological entity by creating land from a naturally inundated area, e.g. by reclaiming land from a lake or sea, or by building barriers around a floodplain or marsh and then draining it. All polders are eventually below the surrounding water table some or all of the time, making them especially prone to flooding.

polar region : Either of the two high-latitude regions surrounding the Earth’s geographical poles (the North and South Poles), which are characterized by frigid climates and extensive polar ice caps. The polar region of the Northern Hemisphere is often simply called the Arctic and that of the Southern Hemisphere is called the Antarctic.

polar ice cap : Also called a polar ice sheet.

Either of the two very large regions near the Earth’s geographical poles that are seasonally or persistently covered in ice, which occurs because high-latitude regions receive less direct solar radiation than other regions and therefore experience much lower surface temperatures. The Earth’s polar ice may cover both land and sea, and varies in size seasonally and with long-term climate change. They typically cover a much larger area than true ice caps and are more correctly termed ice sheets.

polar circle : Either of the two circles of latitude enclosing the Earth’s polar regions: the Arctic Circle in the Northern Hemisphere and the Antarctic Circle in the Southern Hemisphere.

point bar : A depositional feature made of alluvium that accumulates on the inside bend of a meandering stream or river, below the slip-off slope and often directly opposite a cut bank. Point bars are usually crescent-shaped beaches of sand, silt, or gravel, similar to shoals and river islands.

plural society : A situation in which two or more culture groups occupy the same territory but maintain their separate cultural identities

plumb line : A vertical reference line created by suspending a weight, known as a plumb bob or plummet, from a string above the Earth’s surface and allowing it to hang freely in the direction of the pull of gravity. A precursor to the spirit level, plumb lines are used to establish a vertical datum in a wide range of applications, particularly in surveying to determine the nadir of a point in space, and often in combination with an instrument in order to set the instrument precisely over a fixed survey marker.

platted land : Land that has been divided into surveyed lots

plateau: Also called a high plain or tableland.

A large area of relatively flat terrain that is significantly higher in elevation than the surrounding landscape, often with one or more sides with steep slopes.

plate tectonics : A geologic theory that the bending (folding) and breaking (faulting) of the solid surface of the Earth results from the slow movement of large sections of that surface called plates.

plain : Any broad, flat expanse of land that generally does not show significant variation in topography or elevation.

pit crater: Also called a subsidence crater or collapse crater.

A type of crater formed by the sinking or collapse of the surface lying above a void or empty chamber. Pit craters are similar to calderas and are often associated with volcanic activity, but lack the ejecta deposits and lava flows of volcanic craters.

piedmont : Also called foothills.

1.  Any geographic region lying or formed at the base of mountains.2.  In the Southeastern United States, a broad region extending from the Blue Ridge Mountains to the Atlantic coastal plain

physiography : Another name for physical geography

physiographic region : A portion of the Earth’s surface with a common topography and common morphology

physical geography: Also called physiography or geosystems.

The branch of geography that studies processes and patterns in the natural environment, such as the atmosphere, hydrosphere, geosphere, and biosphere, as opposed to the cultural or built environment. Along with human geography, it is one of the two major sub-fields of geography.

photogrammetry : 1.  The science and technology of obtaining reliable information about physical objects and environments through the process of recording, measuring, and interpreting photographic images (usually aerial or orbital ones) and patterns of electromagnetic radiant imagery and other phenomena.2.  The science of extracting three-dimensional measurements from two-dimensional data, such as images.

permafrost : A permanently frozen layer of soil;^[2] permanently frozen ground at high latitude and high elevation

peninsula : A piece of land surrounded by water along the majority of its border while still being connected to a mainland from which it extends.

parish : A type of subnational division of a country or federal state used for religious, administrative or other purposes.

panhole: Also called a gnamma, weathering pit, and solution pan.

A rounded or circular depression eroded into flat or gently sloping cohesive rock, typically shallow and ranging in diameter from a few centimeters to several meters, that is capable of collecting and holding rainwater and snowmelt. The term is sometimes used interchangeably with pothole, though the latter may also refer to distinct geological features.

panhandle : See salient.

palisade : 1.  A wall of wooden stakes used as a defensive barrier.2.  A line of bold cliffs, especially one showing basaltic columns

oxbow : 1.  A wide U-shaped meander in a river or stream.2.  The lake formed when a meander is cut off from the main stem of the river, creating a separate body of water.

overburden : Material covering a mineral seam or bed that must be removed before the mineral can be removed in strip mining

outwash : Rocky and sandy surface material deposited by melted water that flows from a glacier

outcrop: Also called an outcropping.

Any visible exposure of bedrock or ancient superficial deposits on the surface of the Earth, or more generally, any bare, rocky surface that is topographically distinct from the surrounding terrain. Outcrops occur frequently in places where the rate of erosion exceeds the rate of weathering, such as on steep hillsides and mountains, river banks, and coastlines.

orographic rainfall : Precipitation that results when moist air is lifted over a topographic barrier, such as a mountain range.

ordinal directions : See intercardinal directions.

open range : A cattle- or sheep-ranching area characterized by a general absence of fences and in which livestock are allowed to roam freely

ocean trench : A long, narrow, very deep depression in the ocean floor where, at the junction of two tectonic plates, one plate is subducted steeply beneath the other, often penetrating the mantle.

ocean floor : See seabed.

ocean : The vast, contiguous body of salt water covering more than 70% of the Earth’s surface area and surrounding the continental landmasses, or any portion of this larger body of water that is divided and distinguished from the other portions, each of which is called an ocean, by the presence of the landmasses

oasis : A combination of a human settlement and an area of cultivated vegetation in an otherwise desolate desert or semi-desert environment, made fertile when sources of fresh water, such as underground aquifers, irrigate the surface naturally or via man-made wells.

nubbin : A small, gentle hill consisting of a bedrock core dotted with rounded residual boulders. Nubbins form in a similar way to castle koppies and bornhardts.

Northern Hemisphere : The half sphere of the Earth that is north of the Equator. It is opposite the Southern Hemisphere.

North Magnetic Pole: Also called the Magnetic North Pole or Magnetic North.

The point in the Northern Hemisphere at which the Earth’s magnetic field points vertically downward. It is close to but distinct from the Geographic North Pole and the Geomagnetic North Pole, and its precise location varies considerably over time due to frequent magnetic changes in the Earth’s core. Its counterpart in the Southern Hemisphere is the South Magnetic Pole, though the two poles are not directly opposite each other.

North Geomagnetic Pole : Also called the Geomagnetic North Pole.

The point in the Northern Hemisphere where the axis of a theoretical simplified dipole passing through the center of the Earth would intersect the Earth’s surface. It is antipodal to the South Geomagnetic Pole. Because of the fluid nature of the Earth’s molten core, the true axis of the Earth’s magnetic field is not a perfect dipole, and so the Geomagnetic Poles and the actual Magnetic Poles lie some distance apart.

North Geographic Pole: Also called the Geographic North Pole, Geographic North, or simply the North Pole.

The point in the Northern Hemisphere where the Earth’s axis of rotation meets its surface. It is the northernmost point on Earth, directly opposite the South Geographic Pole, and defines the direction of true north at a latitude of 90 degrees North; its longitude can be assigned any degree value. Unlike the South Pole, the North Pole is not located on a continental landmass but in the middle of the Arctic Ocean. See also North Magnetic Pole.

nodal region : A region characterized by a set of places connected to another place by lines of communication or movement

neighborhood : Often abbreviated to hood.

A geographically localized community within a larger city, town, suburb, or rural area, particularly one which supports considerable face-to-face interactions between residents.

neatline : A line separating the main body of a map from the map’s margin. On a standard quadrangle map, the neatlines are the meridians and parallels delimiting the quadrangle.

navigation :

1.  The determination of position and direction, generally by comparing the navigator’s position to known locations or patterns.

2.  The process of monitoring and controlling the movement of a vehicle or craft from one place to another.

natural landscape : The original landscape that exists before it is acted upon by humans. Contrast cultural landscape.

national park : A type of protected area created and managed as a public park by a national governmental authority for conservation purposes. Though individual governments designate national parks differently, they usually share the common goal of preserving natural or semi-natural landscapes (often wilderness) for posterity and as symbols of national pride.

national mapping agency : A governmental agency which manages, produces, and publishes topographic maps, geographic data, and sometimes cadastral information that is specific to an individual nation or political territory, such as the United Kingdom’s Ordnance Survey.

nation : A stable community of people formed on the basis of a common geographic territory, language, economy, ethnicity, or psychological make-up as manifested in a common culture.

narrows: Also called a narrow.

A land or water passage that is confined or restricted by its narrow breadth, often a strait or a water gap.

muskeg : Another name for a bog, used primarily in Alaska and western Canada.

municipality : A type of general-purpose urban administrative subdivision having corporate status and powers of self-government or jurisdiction as granted by national and/or state laws to which it is subordinate. Municipalities are often included within but usually distinguished from larger administrative divisions such as counties, though the nature of their territorial boundaries and political jurisdictions can vary considerably in different parts of the world.

municipal corporation : The legal term for a government body at the local level, including but not necessarily limited to cities, counties, towns, townships, villages, and boroughs

multilingual : The ability to use more than one language when speaking or writing. This term often refers to the presence of more than two populations of significant size within a single political unit, each group speaking a different language as their primary language

mudflow: Also called a debris flow or lahar.

A flowing mixture of water and debris (intermediate between a volcanic avalanche and a water flood) that forms on the slopes of a volcano.^[

mudflat: Also called a tidal flat.

A type of coastal wetland consisting of exposed layers of bay mud formed by the deposition of silts, clays, and marine animal detritus by tides or rivers. Mudflats usually form within the intertidal zone of relatively sheltered areas such as bays and lagoons.

mouth :

1.  The place where a river or stream flows into another body of water, such as a lake or another river but especially a sea or ocean. Deltas and estuaries occur near the mouths of rivers.

2.  The lower or downstream end or the most accessible entrance of a valley, canyon, ravine, or cave.

mountain range : A series of neighboring mountains or hills, often closely arranged in a line and connected by high ground. Individual mountains within the same mountain range are usually the result of the same orogeny, and often (though not always) share a common form, alignment, and geology.

mountain pass : A navigable route through a mountain range or over a ridge, often crossing a saddle.

mountain : A large landform that rises prominently above the surrounding land in a limited area, usually in the form of a rocky peak with great vertical relief; a mountain is generally considered steeper than a hill. Mountains are formed by volcanic or tectonic forces and erode slowly through the actions of rivers, glaciers, and weathering. Most exist within extensive mountain ranges.

mound : Any heaped pile of earth, gravel, sand, rocks, or debris, typically with a rounded top and of topographically higher elevation than its immediate surroundings.

moraine : The rocks and soil carried and deposited by a glacier. An “end moraine,” either a ridge or low hill running perpendicular to the direction of ice movement, forms at the end of a glacier when the ice is melting

moor: Also called moorland.

An upland habitat and ecoregion characterized by low-growing vegetation on acidic soils and generally referring to uncultivated hills but also including low-lying wetlands.

monadnock : See inselberg.

mole : A long, massive, man-made stone or earthen structure used as a pier or breakwater, or as a causeway between places separated by water, but designed to prevent the free movement of water underneath it (unlike a true pier).

mogote : An isolated, rounded, steep-sided hill composed of either limestone, marble, or dolomite and surrounded by nearly flat alluvial plains, especially as found in tropical regions.

metropolitan coalescence : The merging of the urbanized parts of separate metropolitan areas; a megalopolis is a result of this process

metropolitan area: Also called a metro area or commuter belt.

A region consisting of one or more densely populated urban cores (often a metropolis) and its less populous surrounding territories, including satellite cities, towns, and intervening rural areas, all of which are socioeconomically tied to the core as typically measured by commuting patterns. A metropolitan area usually comprises multiple neighborhoods, jurisdictions, and municipalities, with its inhabitants sharing industry, housing, and many other forms of infrastructure.

metropolis : A large city or conurbation which is considered a significant economic, political, or cultural center for a country or geographic region and/or an important hub for regional or international connections and communications.

metropole : The homeland or central territory from which a colonial empire governs, as opposed to its colonies or overseas territories.

metes and bounds : A system of land survey that defines land parcels according to visible natural landscape features and distance. The resultant field pattern is usually very irregular in shape.

metamorphic rock : Rock that has been physically altered by heat and/or pressure

mesa : An isolated, relatively flat-topped natural elevation, usually more extensive than a butte and less extensive than a plateau

meridian : See longitude.

megalopolis : A chain of roughly adjacent metropolitan areas which have merged into a very large and heavily populated urban complex. See conurbation and metropolitan coalescence.

megacity : A very large city, typically with a population of at least 10 million people. Precise definitions vary, but criteria are usually based on total population and/or population density.

Mediterranean climate : Any climate characterized by mild, rainy winters and hot, dry summers, as experienced in the Mediterranean Basin.

MEDC : An acronym for More Economically Developed Country.

meander scar : Also called a meander scarp.

A typically crescent-shaped incision in a bluff or valley wall formed by the remnants of a dry, abandoned meander.

meander : One of a series of regular sinuous curves, bends, loops, turns, or windings in the main channel of a river, stream, or other watercourse. Meanders are produced by the repetitive upstream erosion and downstream deposition of sediments along the banks of a watercourse as the water flows back and forth across the axis of a valley or floodplain.

massif :

1.  Any section of the Earth’s crust which is demarcated by faults or flexures and tends to retain its internal structure while being displaced as a whole.

2.  A single large mountain mass or compact group of connected mountains forming an independent portion of a mountain range.

marsh : A wetland dominated by herbaceous rather than woody plant species and often found at the edges of lakes and streams, where it forms a transition between the aquatic and terrestrial ecosystems.

maritime climate : A climate strongly influenced by an oceanic environment, typically found on islands and the windward shores of continents. It is characterized by small daily and yearly temperature variation and high relative humidity.

map projection : A systematic transformation of the latitudes and longitudes of locations from the surface of a three-dimensional shape, such as a sphere or an ellipsoid, into locations on a two-dimensional plane. Maps of locations on the Earth require map projections to represent features in a convenient format that is easy to view and interpret, though all map projections necessarily distort the true properties of the Earth’s surface to some degree.