Geography (from Greek: γεωγραφία, geographia, literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of Earth. The first recorded use of the word γεωγραφία was as a title of a book by Greek scholar Eratosthenes (276–194 BC). Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be. While geography is specific to Earth, many concepts can be applied more broadly to other celestial bodies in the field of planetary science. One such concept, the first law of geography, proposed by Waldo Tobler, is "everything is related to everything else, but near things are more related than distant things." Geography has been called "the world discipline" and "the bridge between the human and the physical sciences". (Full article...)
A number of ice cores have been obtained from Quelccaya, including two from 1983 that were the first recovered outside of the polar regions. Past climate states have been reconstructed from data in these ice cores; these include evidence of the Little Ice Age, regional droughts and wet periods with historical significance and past and recent El Niño events. The ice cap is regularly monitored and has a weather station. (Full article...)
Willow Lake (located in the Big Butte Creek watershed), with Mount McLoughlin in the background
Big Butte Creek's watershed was originally settled over 8,000 years ago by the Klamath, Upper Umpqua, and Takelma tribes of Native Americans. In the Rogue River Wars of the 1850s, most of the Native Americans were either killed or forced onto Indian reservations. The first non-indigenous settlers arrived in the 1860s, naming the creek after Snowy Butte, an early name for Mount McLoughlin. In the late 19th century, the watershed was primarily used for agriculture and logging. The small city of Butte Falls was incorporated in 1911, and remains the only incorporated town within the watershed's boundaries. (Full article...)
The Central European borders of Brandenburg–Prussia (blue-green) and the Habsburg monarchy (red) in 1756, after Prussia's seizure of Silesia in the First Silesian War
From the 1930s, Coventry City Council began replacing the city's narrow medieval streets with modern roads, to cope with a rapidly growing population. City architect Donald Gibson began work in 1939 on a city centre redevelopment plan which expanded in scope following World War II, in which large areas of the city were destroyed by German bombs. The shopping area was rebuilt first, followed by the ring road, which was constructed in six stages from 1959. Early stages were built with at-grade junctions, cycle tracks and footpaths, envisaged as a surface-level linear park. Following traffic surveys in the early 1960s, however, the council amended the design to include grade separation and the weaving sections. Research by the city engineer indicated that it was the first urban road in the world to use this configuration at such a small scale. The road was completed in 1974, with an overall cost of £14.5 million (equivalent to £160,800,000 in 2021). (Full article...)
It was probably formed by a hotspot in what is present-day French Polynesia before plate tectonics moved it to its present-day location. The Macdonald, Rarotonga, Rurutu and Society hotspots may have been involved in its formation. The first volcanic phase took place in the Cenomanian and was followed by the formation of a carbonate platform that quickly disappeared below the sea. A second volcanic episode between 85 and 78.4 million years ago (in the Campanian) led to the formation of an island. This island was eventually eroded and rudistreefs generated an atoll or atoll-like structure, covering the former island with carbonates and thus a second carbonate platform. (Full article...)
Ice core sample taken from drill
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers (for shallow holes) or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old.
The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core. The proportions of different oxygen and hydrogen isotopes provide information about ancient temperatures, and the air trapped in tiny bubbles can be analysed to determine the level of atmospheric gases such as carbon dioxide. Since heat flow in a large ice sheet is very slow, the borehole temperature is another indicator of temperature in the past. These data can be combined to find the climate model that best fits all the available data. (Full article...)
Calabozos is a Holocenecaldera in central Chile's Maule Region (7th Region). Part of the Chilean Andes' volcanic segment, it is considered a member of the Southern Volcanic Zone (SVZ), one of the three distinct volcanic belts of South America. This most active section of the Andes runs along central Chile's western edge, and includes more than 70 of Chile's stratovolcanoes and volcanic fields. Calabozos lies in an extremely remote area of poorly glaciated mountains.
The outbreak of the Liberal Revolution of 1820 in Lisbon compelled Pedro I's father to return to Portugal in April 1821, leaving him to rule Brazil as regent. He had to deal with challenges from revolutionaries and insubordination by Portuguese troops, all of which he subdued. The Portuguese government's threat to revoke the political autonomy that Brazil had enjoyed since 1808 was met with widespread discontent in Brazil. Pedro I chose the Brazilian side and declared Brazil's independence from Portugal on 7 September 1822. On 12 October, he was acclaimed Brazilian emperor and by March 1824 had defeated all armies loyal to Portugal. A few months later, Pedro I crushed the short-lived Confederation of the Equator, a failed secession attempt by provincial rebels in Brazil's northeast. (Full article...)
Most national parks preserve unique geographic features; Everglades National Park was the first created to protect a fragile ecosystem. The Everglades are a network of wetlands and forests fed by a river flowing 0.25 miles (0.40 km) per day out of Lake Okeechobee, southwest into Florida Bay. The park is the most significant breeding ground for tropical wading birds in North America and contains the largest mangrove ecosystem in the Western Hemisphere. Thirty-six threatened or protected species inhabit the park, including the Florida panther, the American crocodile, and the West Indian manatee, along with 350 species of birds, 300 species of fresh and saltwater fish, 40 species of mammals, and 50 species of reptiles. The majority of South Florida's fresh water, which is stored in the Biscayne Aquifer, is recharged in the park. (Full article...)
The third smallest planet in the Solar System, Venus is a terrestrial planet and is sometimes called Earth's "sister planet" because of their similar size, mass, proximity to the Sun, and bulk composition. It is radically different from Earth in other respects. It has the densest atmosphere of the four terrestrial planets, consisting of more than 96% carbon dioxide. The atmospheric pressure at the planet's surface is about 92 times the sea level pressure of Earth, or roughly the pressure at 900 m (3,000 ft) underwater on Earth. Even though Mercury is closer to the Sun, Venus has the hottest surface of any planet in the Solar System, with a mean temperature of 737 K (464 °C; 867 °F). Venus is shrouded by an opaque layer of highly reflective clouds of sulfuric acid, preventing its surface from being seen from Earth in light. It may have had water oceans in the past, but after these evaporated the temperature rose under a runaway greenhouse effect. The water has probably photodissociated, and the free hydrogen has been swept into interplanetary space by the solar wind because of the lack of a planetary magnetic field. Because of the lethal surface conditions, the planet is sometimes referred to as Earth's "evil twin". (Full article...)
During Pedro II's minority the governing regency faced countless rebellions throughout the country. Again breaking with his father and other relatives sympathetic to the rebels, from 1839 to 1845 Caxias commanded loyalist forces suppressing such uprisings as the Balaiada, the Liberal rebellions of 1842 and the Ragamuffin War. In 1851, under his command, the Brazilian army prevailed against the Argentine Confederation in the Platine War; a decade later Caxias, as army marshal (the army's highest rank), led Brazilian forces to victory in the Paraguayan War. As a reward he was raised to the titled nobility, becoming successively a baron, count, and marquis, finally becoming the only person created duke during Pedro II's 58-year reign. (Full article...)
The General Perspective projection is a map projection used in cartography in which the Earth is depicted as viewed from a finite distance above its surface. If the view precisely faces the center of the Earth, the projection is a vertical perspective projection; otherwise, it is a tilted perspective projection. Here is shown a vertical perspective from an altitude of 35,786 km over (0°, 90°W), corresponding to a view from geostationary orbit. Due to the horizon as seen from the viewpoint position, the projection always shows less than half of the Earth's surface: in this case neither of the North and South Poles is visible.
The Gall–Peters projection, named after James Gall and Arno Peters, is a specialization of a configurable equal-area map projection known as the cylindrical equal-area projection. It achieved considerable notoriety in the late 20th century as the centerpiece of a controversy surrounding the political implications of map design; Peters promoted it as a more faithful representation than the Mercator projection, which inflates the sizes of regions farther from the equator and thus makes the (mostly technologically underdeveloped) equatorial countries appear smaller and therefore, according to Peters, less significant.
The Robinson projection is a projection of a world map showing the entire Earth at once. It was specifically created in an attempt to find a good compromise to the problem of showing the whole globe as a single flat image. The projection was devised by Arthur H. Robinson in 1963; distortion is severe close to the poles, but quickly declines to moderate levels as latitudes decrease. This Robinson-projection map, with standard parallels of 38°N and 38°S, was produced by the United States Central Intelligence Agency and shows the world as of February 2016.
Illustration of the Ptolemaicgeocentric model of the Universe (the theory that the Earth is the center of the universe) by Portuguese cosmographer and cartographer Bartolomeu Velho. Taken from his treatise Cosmographia, made in Paris, 1568. Notice the distances of the bodies to the centre of the Earth (left) and the times of revolution, in years (right).
The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569. Because it represents paths of constant course as straight lines, it long served as the standard map projection for nautical purposes. However, it distorts the size of objects as the latitude increases: thus areas in the mid-latitudes appear significantly larger than their actual size relative to those the equator, and those near the poles are even more exaggerated. Most modern atlases no longer use the Mercator projection for world maps or for areas distant from the equator, preferring other cylindrical projections, or forms of equal-area projection.
Zhang Heng began his career as a minor civil servant in Nanyang. Eventually, he became Chief Astronomer, Prefect of the Majors for Official Carriages, and then Palace Attendant at the imperial court. His uncompromising stance on historical and calendrical issues led to his becoming a controversial figure, preventing him from rising to the status of Grand Historian. His political rivalry with the palace eunuchs during the reign of Emperor Shun (r. 125–144) led to his decision to retire from the central court to serve as an administrator of Hejian Kingdom in present-day Hebei. Zhang returned home to Nanyang for a short time, before being recalled to serve in the capital once more in 138. He died there a year later, in 139. (Full article...)