scale

SCALE IS A FUNDAMENTAL component of geographic events and processes. Climate change occurs at global scales, while human diseases such as measles occur at essentially local and regional scales. Many geographic processes also occur across multiple scales, and more important, some processes behave differently at various scales. Consequently, an explicit statement of scale is required to understand and compare these geographic processes. One […]

Sauer, Carl O. (1889–1975)

Sauer, Carl O. (1889–1975)

CARL ORTWIN SAUER was one of the most influential American geographers. Throughout his long and distinguished career, he shaped and fundamentally changed the field of cultural and anthropogeography in the UNITED STATES. Sauer was of German descent, and his ancestors were members of a German pietistic sect affiliated with the Methodists who had settled in Warrenton, MISSOURI, Sauer's place of birth. After […]

Saudi Arabia

Saudi Arabia

Area 756,984 square mi (1,960,582 square km) Population 30.89 million 2014 Capital Riyadh Highest Point 10,278 ft (3,133 m) Lowest Point 0 m GDP $746.2 billion 2014 Primary Natural Resources petroleum, natural gas, iron ore, gold. LOCATED ON THE ARABIAN Peninsula in the MIDDLE EAST between the ARABIAN SEA, the RED SEA, OMAN, YEMEN, the UNITED ARAB […]

satellites

satellites

THE GLOBAL POSITIONING System (GPS) is a constellation of earth-orbiting satellites developed by the U.S. Department of Defense to provide global, all weather and 24-hour positioning capabilities to ground-based GPS receivers. Although the original system was intended for military use, it has also found important and widespread applications in civilian positioning, navigation, and mapping. Positioning is about determining an exact location based on […]

Sargasso Sea

Sargasso Sea

THE SARGASSO SEA is located in the North ATLANTIC OCEAN. The area of the sea is found between 20 degrees N and 35 degrees N latitude and 30 degrees W and 75 degrees W longitude—the hump extending northward of BERMUDA. This is also known as the “horse latitudes.” The Sargasso Sea, relatively calm and motionless, is unique, as it has no […]

São Tomé and Príncipe

Sao Tome and Principe

Area 386 square mi (1,001 square km) Population 186,300 (2014) Capital Sao Tome Highest Point 6,640 ft (2024 m) Lowest Point 0 m GDP $337.4 million (2014) Primary Natural Resources bananas, cocoa, coconuts, coffee, fish. ONE OF AFRICA'S smallest countries, the Democratic Republic of Sao Tome and Principe consists of two main islands (Sao Tome […]

São Paulo

Sao Paulo

SAO PAULO IS THE largest city in BRAZIL and serves as the capital of the state of Sao Paulo. With a metropolitan area population nearing 20 million at the start of the 21st century, Sao Paulo is the biggest city in South America and one of the fastest-growing urban areas in the world. The city is the industrial center of Brazil, […]

San Marino

San Marino

Area 38 square mi (61.2 square km) Population 31,600 2014 Capital San Marino Highest Point 2,492 ft (755 m) Lowest Point 182 ft (55 m) GDP $1.900 billion 2008 Primary Natural Resources building stone, wheat, grapes, corn. SAN MARINO IS one of Europe's five microstates. Like the others, it is a holdover from a more […]

Samoa

Samoa

Area 1,137 square mi (2,944 square km) Population 191,800 2014 Capital Apia Highest Point Mauga Silisili 6,092 ft (1,857 m) Lowest Point 0 m GDP $800.4 million 2014 Primary Natural Resources hardwood forests, fish. THE SAMOAN ARCHIPELAGO lies approximately midway between the Hawaiian islands and NEW ZEALAND and consists of scores of islands and atolls. Human […]

Samarqand

Samarqand

SAMARQAND (SAMARKAND), the second-largest city in UZBEKISTAN, is known as the mirror of the world, the garden of the soul, the jewel of ISLAM, the pearl of the East, the center of the universe, and the city of famous shadows. In the Zerafshan Valley, with high snowcapped mountains of the Pamir–Altai mountain spurs on the northeast, it is an oasis on […]

Sakhalin Island

Sakhalin Island

SAKHALIN IS THE LARGEST island of the Russian Federation, 589 mi (948 km) long and 16 to 105 mi (25 to 170 km) wide, with an area of 24,560 square mi (78,000 square km). Sakhalin is separated from the mainland by the narrow and shallow Mamiya Strait or Strait of Tartary, which often freezes in winter in its narrower part, and […]

Saint Vincent and the Grenadines

Saint Vincent and the Grenadines

Area 152 square mi (389 square km) Population 109,400 2014 Capital Kingstown Highest Point Soufriere 4,072 ft (1,234 m) Lowest Point 0 m GDP $729.3 million 2014 Primary Natural Resources hydropower, cropland. THE COUNTRY OF Saint Vincent and the Grenadines is located in the Windward Islands section of the Antilles chain, between SAINT LUCIA and GRENADA in […]

Saint-Pierre and Miquelon

Saint-Pierre and Miquelon

AS FRENCH TERRITORIES (93 square mi or 242 square km) and a curious leftover from the chessboard games of colonial diplomacy of the 18th-century great powers, the tiny islands of Saint-Pierre and Miquelon are the only remaining fragments of the once mighty French North American empire. Consisting of two small islands, no more than barren rocks with two small settlements, the territory's […]

Saint Petersburg

Saint Petersburg

THE CITY OF SAINT Petersburg in RUSSIA is known throughout the world as one of the marvels of urban planning and magnificent architecture. As the capital of the Russian Empire from 1712 to 1918, the city was the staging ground for the dramatic events of Russian history, from Peter the Great's forced introduction of Western (modern) customs in the early 18th […]

Saint Lucia

Saint Lucia

Area 238 square mi (616 square km) Population 183,600 2014 Capital Castries Highest Point 3,135 ft (950 m) Lowest Point 0 m GDP $1.404 billion 2014 Primary Natural Resources forests, minerals (pumice), geothermal potential. THE COUNTRY OF SAINT LUCIA is the secondlargest and the most picturesque of the Windward Islands. The island is known for its beauty […]

Saint Kitts and Nevis

Saint Kitts and Nevis

Area 102 square mi (261 square km) Population 54,940 2014 Capital Basseterre Highest Point 3,815 ft (1,156 m) Lowest Point 0 m GDP $852.2 million 2014 Primary Natural Resources arable land, sugarcane, rice, yams, vegetables. THE FEDERATION OF SAINT KITTS and Nevis together form one of the newest nations in the Western Hemisphere. Formerly part of the […]

Sahel

Sahel

SAHEL (OR SAHIL) MEANS “edge or border” in Arabic. The Sahel is a semiarid transitional zone between the southern edge of the SAHARA DESERT and the humid savannah zone of Africa. On average it is 187 mi (300 km) wide. It has a fragile ecology but is also diverse in plant and animal species. The Sahel stretches across North Africa from […]

Sahara Desert

Sahara Desert

THE SAHARA IS THE world's largest desert. Covering about 3,320,000 square mi (8,600,000 square km) it is roughly the size of the UNITED STATES. It extends across the whole of North Africa from the ATLANTIC OCEAN to the RED SEA, a distance of more than 3,500 mi (5,630 km). It stretches south for at least 1,200 mi (1,930 km). The Sahara […]

Rwanda

Rwanda

Area 16,365 square mi (26,338 square km) Population 11.34 million (2014) Capital Kigali Highest Point 14,826 ft (4,519 m) Lowest Point 3,100 ft (950 m) GDP $7.890 billion (2014) Primary Natural Resources gold, cassiterite (tin ore). RWANDA, LOCATED in Central Africa, is a landlocked country of savanna GRASSLAND with a population that is predominantly rural. It is […]

Ruwenzori Mountains

Ruwenzori Mountains

SHROUDED IN MISTS sitting under the hot sun of the equator is a mountain range believed to be the mysterious “Mountains of the Moon” spoken of by the ancient Greeks. Their discovery is actually credited to Henry Morton Stanley of Britain, who in 1888, while on expedition, glanced up one day and saw what the native porters at the time believed […]

Russian Federation map

Russian Federation

Area 6.6 million square mi (17 million square km) Population 143.8 million 2014 Capital Moscow Highest Point 18,476 ft (5,633 m) Lowest Point -91 ft (-28 m) GDP $1.861 trillion 2014 Primary Natural Resources oil, natural gas, coal. STRETCHING IN A GIGANTIC arc around the ARCTIC OCEAN and North Pole, the Russian Federation spans 11 time zones, nearly half the globe from east […]

Ruhr Valley

Ruhr Valley

IN TERMS OF LENGTH and volume, the Ruhr River is not one of GERMANY's major rivers. But considered as a center of economic activity, the Ruhr is among the most prominent rivers in Europe. Starting in the early 19th century, the coal that was mined in this region was processed in factories all along the river's course, creating one of the […]

Rub’ al-Khali

Rub’ al-Khali

THE RUB' AL-KHALI (Arabic for “Empty Quarter”) is located in the southern part of the Arabian Desert. The Al-Murrah Bedouin, who roam its southern edges call it the ar-Ramlah, the “sand.” It covers an area of about 250,000 square mi (647,500 square km). It is somewhat smaller than TEXAS or about as large as FRANCE together with BELGIUM and Holland. Most […]

rotation, Earth axis

rotation, Earth axis

EARTH HAS TWO primary motions: revolution and rotation. The first refers to the earth's annual orbit of the sun, which takes a bit more than 365 days per year (hence, a leap year with 366 days every four years in order to “catch up”). As it revolves around the sun, the Earth rotates on its axis once every 24 hours, […]

Romania map

Romania

Area 91,000 square mi (237,500 square km) Population 19.91 million 2014 Capital Bucharest Highest Point 8,346 ft (2,544 m) Lowest Point 0 m GDP $199.0 billion 2014 Primary Natural Resources oil, natural gas, timber, coal, iron ore. ROMANIA IS AN OVAL-shaped country in southeastern Europe. Situated in the northeastern part of the Balkan Peninsula, it is halfway between the ATLANTIC OCEAN and the […]

Rocky Mountains

Rocky Mountains

THE ROCKY MOUNTAINS are a chain of mountain ranges 3,000 mi (4,800 km) long and as wide as 350 mi (563 km) running predominantly north to south in the western part of the North American continent. The Rockies run through the U.S. states of NEW MEXICO, COLORADO, UTAH, WYOMING, IDAHO, MONTANA and ALASKA, as well as the Canadian provinces of Alberta and […]

river

river

A RIVER IS A LARGE STREAM OF WATER flowing in a bed or channel and emptying into the ocean, a sea, a lake, or another stream. Rivers have a starting point called a source, and a mouth, where they empty into a larger body of water. Its source may be a spring, lake, or mountain snowmelt, and its ultimate destination […]

riparian

riparian

RIPARIAN IS DERIVED from the Latin riparius, meaning “of the river bank.” The term was historically used to describe the area of land lying adjacent to a body of water: primarily streams or rivers but also lakes. Riparian areas are ecotones—transition areas or interfaces between terrestrial and aquatic ECOSYSTEMs. As such, riparian areas possess features and processes influenced by adjacent ecosystems as […]

Rio Grande

Rio Grande

THE RIO GRANDE was once known as “Rio del Norte,” and the first to describe it to Europeans was Captain General Juan de Onate, whose party of exploration first visited the river on April 20, 1598. The river was then called Corre del Norte, meaning that its current ran from the north. It is the second-largest river in North America, running […]

Ring of Fire

Ring of Fire

The Pacific Ring of Fire is an arc of intense EARTHQUAKE (seismic) and volcanic activity stretching from NEW ZEALAND, along the eastern edge of Asia, north across the ALEUTIAN ISLANDS of ALASKA, and south along the coast of North and South America. It is made up of over 75 percent of the world's active and dormant volcanoes. The Ring of Fire […]

rift valley

rift valley

A RIFT VALLEY IS A trenchlike basin with steep parallel sides. The valley is essentially a down-faulted crustal block (grabben) between two parallel faults. A rift valley is different from an ordinary grabben for its remarkable length and depth. Such extraordinary basins typically occur where tectonic plates diverge. The release of Earth's interior energy creates most rift valleys in the processes of […]

Rhône River

Rhone River

THE RHONE IS THE chief river of southeastern FRANCE, draining much of the western ALPS and connecting the regions of the interior to the MEDITERRANEAN coast. From its rise in the Swiss Alps to its wide DELTA, the Camargue, the river travels 500 mi (800 km), at first through narrow and twisting mountain valleys, but from Lyon to the sea (170 […]

Rhode Island

Rhode Island

RHODE ISLAND, SMALLEST of the 50 United States at 1,214 square mi (3,144 square km), is located in New England on the ATLANTIC seaboard. It is bounded by MASSACHUSETTS on the north and east, the Atlantic Ocean to the south, and CONNECTICUT in the west. While it is typically referred to as Rhode Island, the official name is actually the State […]

Rhine River

Rhine River

WITH A TOTAL LENGTH of 820 mi (1,320 km) flowing through SWITZERLAND, GERMANY, and the NETHERLANDS, the Rhine is the longest river in Germany and probably the most important waterway of western Europe. The Vorderhein, Hinterrhein, and Alpenrhein are the sources of the river within Switzerland. The Rhine then enters the Bodensee (Lake Constance) and reemerges as the Hochrhein up to Basel […]

resource

resource

THE WORD resource is derived from the Latin resurgere, meaning to “rise again.” Therefore, a resource can be part of a cyclical process that can change and return over time and space. Resources are those elements that humans have the knowledge and technology to utilize to provide desired goods and services. Resources are subjective, functional, and dynamic. They can be tangible things […]

religion

religion

RELIGION CAN BE DEFINED as a unified set of beliefs, values, and practices of an individual or a group of people that is based on the teachings of a spiritual leader. It includes codes of behavior, faith in and devotion toward a supernatural power or powers, and a framework for understanding the universe. Religion is an important component of many individuals' […]

regionalism

regionalism

REGIONALISM IS A COMPLEX and contested concept. As such, there is no straight or simple answer to what regionalism is. One thing for sure is that regionalism is closely related to REGION. Since a region may connote geographical contiguity ranging from a small neighborhood to a few cities right up to several states and continents, regionalism thus can exist within a state, […]

region

region

THE NOTION OF REGIONS has been central to geographic thinking, first because of the importance of the observation and its corollary, and second because of the classification in classic geography emphasized by the empiricism and primacy of the field survey. The term region originates from Old French and stems from the Latin regio, meaning “direction and district,” and from regere, meaning “to […]

redistricting

redistricting

THE PROCESS OF redistricting means dividing anew into districts or, in particular, to revise the legislative districts of a certain area, typically of a city or state. In the UNITED STATES, the process of redistricting is also referred to as “legislative reapportionment,” which the U.S. Constitution requires so that Congressional representatives are elected according to population. The process of redistricting redraws the […]

Red Sea

Red Sea

THE RED SEA CONNECTS the MEDITERRANEAN SEA to the INDIAN OCEAN via the Suez Canal. It lies in the Great Rift Valley between Africa and the Arabian Peninsula. EGYPT, SUDAN, ERITREA, and DJIBOUTI border it to the west, while ISRAEL is to the north and JORDAN, YEMEN, and SAUDI ARABIA are the to the east. Scientists believe it was formed 20 […]

rainforests

rainforests

THE WORLD'S RAINFORESTS are often considered the world's “hot spots” since they are often found in tropical climates and they are home to the majority of the world's species. As of 2000, studies and surveillance indicated that rainforests may have from one-half to two-thirds of the world's species, despite only covering 5–7 percent of the world's surface. Biodiversity is just one of […]

Quaternary geography

Quaternary geography

THE QUATERNARY PERIOD is the time in which people became fully human and the dominant animal species on earth. The Quaternary is Earth's most recent geological period and includes the Pleistocene and Holocene epochs. (Eras, periods, and epochs comprise the geological calendar. An era is the longest unit of geologic time. Traditionally, geologists identify periods as beginning and ending with the appearance […]

Qatar map

Qatar

Area 4,415 square mi (11,437 square km) Population 2.172 million 2014 Capital Doha Highest Point Qurayn Abu al Bawl 338 ft (103 m) Lowest Point 0 m GDP $210.1 billion 2014 Primary Natural Resources petroleum, natural gas, fish. QATAR IS LOCATED in the MIDDLE EAST; it is a peninsula projecting into the PERSIAN GULF and bordered […]

Pyrenees

Pyrenees

THE PYRENEES MOUNTAINS form the natural border between FRANCE and SPAIN, and have been a more effective barrier between the two nations than other ranges of similar height because of their characteristic ruggedness and lack of usable passes. Even more so than the ALPS, the Pyrenees were impassable to travelers for many centuries. Today, however, […]

Puncak Jaya

Puncak Jaya

PUNCAK JAYA, THE highest peak of the Sudirman Range of Papua, is also the highest mountain between the ANDES and the HIMALAYAS, rising to 16,503 ft (5030 m) on the tropical island of New Guinea. It was first named Mount Carstenz after the Dutch navigator Jan Carstenz, who first sighted the peak from the coast […]

Puerto Rico

Puerto Rico

THE ESTADO LIBRE Asociado de Puerto Rico is a densely populated island in the eastern Greater Antilles in the CARIBBEAN SEA, divided into 78 counties. Even though it is a possession of the UNITED STATES, Puerto Rico is an independent commonwealth and has selfgovernance in all its local affairs. The rectangularshaped, mostly mountainous volcanic island […]

Ptolemy

Ptolemy

KLAUDIOS PTOLEMAIOS, known as Ptolemy in English, lived in Alexandria, EGYPT, in the second century C.E. He is considered one of the most important scientists of the later Classical era, with two major treatises in the areas of astronomy and geography. His geocentric model of the universe was the standard accepted view of the cosmos […]

projection, maps

projection, maps

THE EARTH CAN BE assumed as a perfect sphere for purposes of simplicity. However, in reality there is a large difference between the pole-to-pole distance and the equator distance. The Earth is about 1/300th smaller in its pole to pole distance. This unique shape is called an oblate ellipsoid or spheroid. An estimate of the ellipsoid […]

precipitation

precipitation

PRECIPITATION IS WATER falling from clouds. In the tropics, rain is the common form. In colder climates, precipitation also falls as snow, sleet, or hail, if the air temperature is 32 degrees F (0 degrees C) or less. Water's descent from clouds begins when the size of water droplets or ice crystals becomes large enough for […]

prairie

prairie

BEFORE NORTH AMERICA was populated by settlers who developed the land, most of the continent was covered by flat grass-covered areas known as prairie, stretching from CANADA to MEXICO. By the beginning of the 21st century, 99 percent of the original prairie had been destroyed. The provinces of Alberta, Saskatchewan, Manitoba, and Ontario are part […]

Portugal map

Portugal

Area 35,672 square mi (92,391 square km) Population 10.40 million 2014 Capital Lisbon Highest Point Pico 7,713 ft (2,351 m) Lowest Point 0 m GDP $229.6 billion 2014 Primary Natural Resources forests, cork, marble, fisheries. THE PORTUGUESE REPUBLIC is located in southwestern Europe, sharing the Iberian Peninsula with SPAIN, which it borders to the north […]

Polynesia map

Polynesia

POLYNESIA, MEANING “many islands” (Greek), is one of the three main divisions (the others being MICRONESIA and MELANESIA) of Oceania. This division is based upon the ethnological background of the different islands' inhabitants. Geographically, Polynesia is a triangle area of islands, with the Hawaiian Islands at one corner, NEW ZEALAND at another, and EASTER ISLAND […]

Polo, Marco (1254–1324)

Polo, Marco (1254–1324)

MARCO POLO IS THE best known of all Western travelers along the SILK ROAD. He traveled Asia for 24 years, all the way to CHINA, where he became confidant of Kublai Khan (1214–94.) He also wrote of his travels. Marco was born in ITALY, either in Curzola off the Dalmatian coast or in Venice, in […]

political geography

political geography

POLITICAL GEOGRAPHY IS the study of the ways geographic space is organized within and by political processes. It focuses on the spatial expression of political behavior. Boundaries on land and on the oceans, the role of capital cities, power relationships among nation-states, administrative systems, voter behavior, conflicts over resources, and even matters involving outer space […]

Poland map

Poland

Area 120,728 square mi (312,685 square km) Population 38.00 million 2014 Capital Warsaw Highest Point 8,199 ft (2,499 m) Lowest Point -6.6 ft (-2 m) GDP $548.0 billion 2014 Primary Natural Resources coal, sulfur, copper, natural gas, silver. POLAND IS LOCATED in eastern Europe, and is surrounded by the Baltic Sea to the northwest, GERMANY […]

Po Valley

Po Valley

THE PO RIVER VALLEY is the largest and most important economic region in ITALY. It is the center of most Italian industry as well as Italy's agricultural heartland. More than 16 million people—nearly a third of all Italians—live in this fertile basin, in which are located 12 cities with populations surpassing 100,000, including Turin and […]

Pleistocene geography

Pleistocene geography

THE PLEISTOCENE EPOCH was Earth's most recent Ice Age. The epoch began around 1.8 million years ago (mya) or 2.6 mya. Traditionally, scientists have based the starting date of the epoch on faunal grounds and have estimated it to be about 1.8 mya. A growing number of climate scientists and glaciologists tend to use 2.6 […]

playa

playa

PLAYAS ARE SHALLOW basins that periodically fill with rainwater. They have been described as among the most dynamic geomorphic features, reacting to seasonal and sometimes daily changes in the environment. The term playa owes its origin to the Spanish word for “beach” or “shore.” A large number of playas began as lakes, drying later as […]

plateau

plateau

A PLATEAU IS A LARGE area of mostly level land elevated high above the surrounding land. Most plateaus have one steeply cliffed side. The rock layers in a plateau are un-deformed and remain flat, unlike the rock layers in mountains, which are tilted. Basaltic plateaus are formed when molten rock forces its way up through […]

plate tectonics

plate tectonics

PLATE TECTONICS IS A geological theory that explains many important features of the Earth's surface through the movement of sections of the crust, known as plates. Among the observed data explained by plate tectonics are the known similarities of features on the east and west sides of the ATLANTIC OCEAN, similarities of plant and animal […]

planning

planning

WHILE PLANNING IN ITS MOST literal form refers to the creation of a plan in an urban context, in reality the term has a far broader and more complicated definition. For example, planning can refer to matters of safety, that is, the prevention of natural disaster, as well as issues such as aesthetics, the environment, […]

place

NOTHING IS MORE important to all geography, descriptive or analytical, natural or human, than place or location. Place can be divided into at least three distinct aspects: geometric location defined by precise latitude and longitude; relative location of where a place is relative to other places, especially in the context of history; and finally, the […]

Pitcairn Island

Pitcairn Island

PITCAIRN (18.1 square mi or 47 square km) is an isolated island located in the east-central PACIFIC OCEAN, approximately 400 mi (644 km) southeast of Mangareva, the closest inhabited island. Pitcairn is the only inhabited island of the British colony of Pitcairn, Henderson, Ducie, and Oeno Islands. The three outer islands of the Pitcairn Islands […]

physical geography

physical geography

PHYSICAL GEOGRAPHY IS AN integral part of a much larger area of understanding called geography. Most individuals define geography as a field of study that deals with maps. This definition is only partially correct. A better definition of geography may be the study of natural and human phenomena relative to a spatial dimension. The discipline […]

Phoenicia

Phoenicia

ANCIENT PHOENICIA, A LOOSE confederation of city-states existing between 3000 B.C.E. and 146 B.C.E., was located where LEBANON is now. The culture was known for seafaring commerce and trade, and colonizing. The most important legacy left by the Phoenicians, though, was a 22-character alphabet that became the basis of Hebrew, Greek, and Roman script. In […]

Philippines map

Philippines

Area 115,831 square mi (300,000 square km) Population 99.14 million 2014 Capital Manila Highest Point 9,691 ft (2,954 m) Lowest Point 0 m GDP $284.6 billion 2014 Primary Natural Resources timber, petroleum, nickel, cobalt, gold. OFF THE SOUTHEAST COAST of mainland Asia lies the Philippines, a southeast Asian country that consists of an archipelago in […]

Petra

Petra

PETRA HAS BEEN described in National Geographic magazine as being “JORDAN's city in the rock.” There is no doubt, however, that Petra, located south of Amman on a semiarid site at the edge of the Wadi Araba mountainous desert, is a wonder of the ancient world. Originally developed at the crossroads of overland trading routes, […]

Peru map

Peru

Area 496,226 square mi (1,285,220 square km) Population 30.97 million 2014 Capital Lima Highest Point 22,205 ft (6,768 m) Lowest Point 0 m GDP $202.9 billion 2014 Primary Natural Resources copper, silver, gold, petroleum, timber, fish, iron. PERU IS A country of contrasts. The fourth-largest country in Latin America, Peru has an amazing geography, a […]

Persian Gulf

Persian Gulf

THE COUNTRIES BOUNDING the Persian Gulf include OMAN, UNITED ARAB EMIRATES, QATAR (a peninsula off the SAUDI ARABIA coast), BAHRAIN (an island), Saudi Arabia, KUWAIT, IRAQ, and in the north, IRAN. The Persian Gulf is an arm of the ARABIAN SEA extending some 600 mi (970 km) from east to west. It covers an area […]

Persian Empire

Persian Empire

THE PERSIAN EMPIRE was one of the first of the world empires to emerge in the ancient Middle East, the first to unify several different peoples and cultures into one large heterogeneous state. Much of this work was achieved by the emperors Cyrus and Darius, who recognized the strength of diversity, picking the best of […]

Persepolis

Persepolis

ONE OF THE MOST magnificent cities of the ancient world, Persepolis was the political, cultural, and religious center of the Achaemenian PERSIAN EMPIRE for over 200 years before its complete destruction at the hands of Alexander the Great in 330 B.C.E. The ruins of Persepolis lie at the foot of Kuh-i-Rahmat, the “Mountain of Mercy,” […]

Pennsylvania

Pennsylvania

THE COMMONWEALTH OF Pennsylvania, also known as the Keystone State, is located in the northeastern UNITED STATES. With a total area of 46,058 square mi (119,290 square km), Pennsylvania extends 307 mi (494 km) from east to west and 175 mi (282 km) north to south. It is bordered by NEW YORK and Lake ERIE […]

peninsula

peninsula

A PENINSULA IS AN area of land that projects out into a body of water that surrounds it on three sides. Some peninsulas, like Baja California, are joined to the mainland only by a narrow neck of land called an isthmus. Others, such as INDIA, are connected to the mainland by a wide area of […]

Paris

Paris

PARIS IS NOT ONLY the capital city of FRANCE, it is also the largest city in the country. The census of 1999 showed that although the city itself, which covers 40.5 square mi (105 square km), is relatively demographically small by world standards, having a population of about 2.15 million, the greater Paris metropolitan (aire […]

Paraguay map

Paraguay

Area 157,047 square mi (406,750 square km) Population 6.553 million 2014 Capital Asuncion Highest Point 2,762 ft (842 m) Lowest Point 151 ft (46 m) GDP $30.98 billion 2014 Primary Natural Resources cotton, sugarcane, soybeans. THE REPUBLIC OF PARAGUAY is a LANDLOCKED country located in the central region of South America bordered by BOLIVIA, ARGENTINA, […]

Papua New Guinea map

Papua New Guinea

Area 178,707 square mi (462,840 square km) Population 7.464 million 2014 Capital Port Moresby Highest Point 14,793 ft (4,509 m) Lowest Point 0 m GDP $15.41 billion 2013 Primary Natural Resources gold, silver, copper, natural gas, timber. PAPUA NEW GUINEA IS an archipelago that includes the eastern half of the equatorial island of New Guinea, […]

Pantanal

Pantanal

LOCATED IN SOUTH-CENTRAL BRAZIL and extending into the adjacent parts of BOLIVIA and PARAGUAY, the Pantanal is the world's largest wetland. It can expand during the rainy season to cover about 77,000 square mi (200,000 square km), which is about one-third the size of FRANCE. Water depths may exceed 18 ft (6 m), with only the […]

Pannonian Plain

Pannonian Plain

ALSO KNOWN AS the Hungarian Plain, the Pannonian Plain is one of the flattest parts of Central Europe and one of the most agriculturally productive. The plain occupies a wide depression between the Alpine ranges to the west and south and the Carpathian chain to the north and east. At its greatest extent, the plain […]

Panama Canal

Panama Canal

A CANAL THAT LINKS the ATLANTIC and PACIFIC oceans through the isthmus of PANAMA from northwest to southeast, the Panama Canal is 51 mi (82 km) long. A trip through the canal takes approximately eight hours. The Panama Canal consists of a system of six locks that help ships negotiate the water levels of the […]

Panama map

Panama

Area 30,193 square mi (78,200 square km) Capital Panama City Population 3.868 million 2014 Highest Point 11,400 ft (3,475 m) Lowest Point 0 m GDP $46.21 billion 2014 Primary Natural Resources bananas, rice, corn, coffee, sugarcane. The Republic of Panama is a Central American country bordered both by the CARIBBEAN SEA and the PACIFIC OCEAN, […]

pampas

pampas

THERE ARE MANY types of GRASSLANDs worldwide, especially in the continental interiors of temperate to subtropical regions. That of South America is known as the pampas, a Spanish term. The pampas occupies some 270,270 square mi (700,000 square km) in the countries of ARGENTINA, URUGUAY, and southeast BRAZIL. Here, there are extensive plains with isolated […]

Pamir Knot

Pamir Knot

THE UNIQUE OROGRAPHIC feature known as the Pamir Knot takes its name from the mountains on which it is centered, the Pamir. The “knot” refers to the convergence of some of the world's major mountain ranges, including the TIAN SHAN, Karakorum, Kunlun, HINDU KUSH, and Pamir systems. The origin of the word pamir is unclear, […]

Palau

Palau

Area 179 square mi (458 square km) Population 21,100 2014 Capital Koror Highest Point Mount Ngerchel-chuus 798 ft (242 m) Lowest Point 0 m GDP $250.6 million 2014 Primary Natural Resources forests, minerals, gold. PALAU (OR BELAU to its natives) is one of the world's newest nations, finally securing independence (in Free Association status) with […]

Pakistan map

Pakistan

Area 310,413 square mi (803,940 square km) Population 185.0 million 2014 Capital Islamabad Highest Point 28,251 ft (8,611 m) Lowest Point 0 m GDP $246.9 billion 2014 Primary Natural Resources natural gas, petroleum, coal, iron ore. PAKISTAN CAME INTO being in 1947 when British colonial India, upon independence, was divided into Muslim-dominated East Pakistan (BANGLADESH as […]

Pacific Ocean

Pacific Ocean

THE PACIFIC OCEAN HAS an area of approximately 68,767,000 square mi (178,106,000 square km) with its adjacent seas; 65,329,000 square mi (169,202,000 square km) without them. As the world's largest ocean, it has the following characteristics. Volume: 160,489,000 cubic mi (674,052,000 cubic km) including adjacent areas; 158,065,000 cubic mi (663,871,000 cubic km) if they are […]

Ottoman Empire

THE OTTOMAN DYNASTY created the most enduring empire in human history. The Ottomans originally migrated from Central Asia as nomads and settled in the early 14th century as a military Turkic principality in western Anatolia (present-day TURKEY), between the frontier zone of the Seljuk state and the Byzantine Empire. The Ottomans emerged into a dominant […]

orographic precipitation

OROGRAPHIC PRECIPITATION is caused or enhanced by one or more of the effects of mountains on the Earth's atmosphere. These effects include the upward or lateral motions of air directly caused by mountains acting as a barrier as well as the thermal effects of the mountains that cause them to be elevated heat or cold sources. […]

orogeny

OROGENY, A GEOLOGIC CONCEPT, comes from the Greek oros, meaning “mountain,” and genes, meaning “stemming from.” The etymology associates the term with the concept of building mountains, and in the past, orogeny was associated with mountain formation. Its specific use, today however, relates to the deformation of rocks that leads to postorogenic mountain building. The thrusting, […]

Oregon

OREGON IS A STATE located on the west coast of the UNITED STATES and has a landscape for just about everyone: mountains; FORESTS; plains; DESERTS; the Columbia River Gorge; waterfalls such as Multnomah Falls (620 ft or 189 m), the tallest in Oregon and the fourthtallest in the country; Mills End Park, the smallest park […]

Ontario, Lake

LAKE ONTARIO, BORDERED by the UNITED STATES (NEW YORK state) and CANADA (province of Ontario), is the smallest and easternmost of the five Great Lakes, covering an area of 7,320 square mi (18,960 square km). It is 193 mi (311 km) long and 53 mi (85 km) wide, with a shoreline of approximately 480 mi […]

Oman

Area 82,031 square mi (212,460 square km) Population 4.236 million 2014 Capital Muscat Highest Point 9,776 ft (2,890 m) Lowest Point 0 m GDP $81.80 billion 2014 Primary Natural Resources petroleum, copper, asbestos, natural gas. OMAN IS LOCATED in the MIDDLE EAST, bordering the ARABIAN SEA, Gulf of Oman, and PERSIAN GULF, between YEMEN and […]

Olduvai Gorge

OLDUVAI GORGE IS LOCATED in the East African Rift Valley of northeastern TANZANIA, on the eastern edge of the Serengeti Plain. Discoveries of fossils dating back 1.8 million years were made there by Louis and Mary Leakey, and Donald Johansen. The gorge is now part of the Ngorongoro Conservation Area and lies just to the […]

Oklahoma

LOCATED MIDWAY BETWEEN the east and west coasts of the UNITED STATES and just south of the geographic center of the United States in KANSAS, Oklahoma is one of the Great Plains states. The name comes from the Native American Choctaw language as okla meaning “people,” and humma meaning “red.” Despite images to the contrary, […]

Okavango

COVERING AN AREA roughly the size of CONNECTICUT, Okavango is the largest inland DELTA in the world. It is located in north-central BOTSWANA in the middle of the KALAHARI DESERT and is formed by the Cubango and Cuito rivers flowing out of mountains in ANGOLA and into the Okavango River. Okavango covers a swampy depression […]

Ohio

OHIO IS A MIDWESTERN state in the Great Lakes region of the UNITED STATES. Interestingly, when the first settlers were arriving, the area was considered to be America's great northwest. In the northeast, Ohio is bordered by PENNSYLVANIA from Lake ERIE southward to the Ohio River near East Liverpool. The Ohio River forms a natural […]

Ob-Irtysh River

THE OB AND THE IRTYSH rivers together form one of the largest river BASINs in the world, but also drain an area among the least populated and least known to outsiders. The rivers flow from the isolated mountain ranges of Central Asia (the ALTAI and Sayan ranges) across the sparsely populated Western Siberian Lowland to […]

Nubia

NUBIA, KNOWN AS THE Gateway to the SUDAN, does not exist as a political entity in the 21st century. Geographically, the section of Northeast Africa that was once Nubia has been encompassed into northern Sudan and southern EGYPT, with cataracts (areas where geological forces have formed outcroppings of rock) along the NILE RIVER determining Nubia's […]

Norway

Area 125,182 square mi (324,220 square km) Population 5.136 million 2014 Capital Oslo Highest Point 8,148 ft (2,469 m) Lowest Point 0 m GDP $500.1 billion 2014 Primary Natural Resources petroleum, copper, natural gas, pyrites, nickel. NORWAY IS A LONG, narrow country, stretching from the North Sea to the ARCTIC OCEAN, roughly the same length […]

Northern Mariana Islands

A COMMONWEALTH IN political union with the UNITED STATES, the Northern Mariana Islands (or CNMI) consists of a string of fourteen volcanic and limestone islands in the far western PACIFIC OCEAN. The islands have closer ties to American and European culture than most others in the region and have therefore opted to retain political and […]

North Slope

THE NORTH SLOPE of ALASKA stretches from the high mountains of the Brooks Range to the ARCTIC OCEAN on the north. Miles of barren coastal plains and low, rolling hills, caused by freezing and thawing of the ground, make up the region. No trees are in evidence, as the short growing season will support only […]