Topography is the study of the shape and features of the surface of the Earth and other observable astronomical objects including planets and asteroids. The topography of an area could refer to the shapes and features themselves. This field of geoscience and planetary science is concerned with detail in general, including not only relief but natural and artificial features. This meaning is common in the United States, where topographic maps with elevation contours have made topography synonymous with relief. The older sense of topography as the study of place still has currency in Europe, topography in a narrow sense involves the recording of relief or terrain, the three-dimensional quality of the surface, and the identification of specific landforms. This is known as geomorphometry, in modern usage, this involves generation of elevation data in digital form. It is often considered to include the representation of the landform on a map by a variety of techniques, including contour lines, hypsometric tints.
The term topography originated in ancient Greece and continued in ancient Rome, the word comes from the Greek τόπος and -γραφία. In classical literature this refers to writing about a place or places, in Britain and in Europe in general, the word topography is still sometimes used in its original sense. Detailed military surveys in Britain were called Ordnance Surveys, and this term was used into the 20th century as generic for topographic surveys, the earliest scientific surveys in France were called the Cassini maps after the family who produced them over four generations. The term topographic surveys appears to be American in origin, the earliest detailed surveys in the United States were made by the “Topographical Bureau of the Army, ” formed during the War of 1812, which became the Corps of Topographical Engineers in 1838. In the 20th century, the term started to be used to describe surface description in other fields where mapping in a broader sense is used. An objective of topography is to determine the position of any feature or more generally any point in terms of both a horizontal coordinate system such as latitude and altitude, identifying features, and recognizing typical landform patterns are part of the field.
There are a variety of approaches to studying topography, which method to use depend on the scale and size of the area under study, its accessibility, and the quality of existing surveys. Work on one of the first topographic maps was begun in France by Giovanni Domenico Cassini, in areas where there has been an extensive direct survey and mapping program, the compiled data forms the basis of basic digital elevation datasets such as USGS DEM data. This data must often be cleaned to eliminate discrepancies between surveys, but it forms a valuable set of information for large-scale analysis. The original American topographic surveys involved not only recording of relief, remote sensing is a general term for geodata collection at a distance from the subject area. Besides their role in photogrammetry and satellite imagery can be used to identify and delineate terrain features, certainly they have become more and more a part of geovisualization, whether maps or GIS systems
New Guinea is a large Island in the South West Pacific region. It is the worlds second-largest island, after Greenland, covering an area of 785,753 km2. The island is divided between two countries, Papua New Guinea to the east, and Indonesia to the west, the island has been known by various names. The name Papua was used to refer to parts of the island before contact with the West and its etymology is unclear, one theory states that it is from Tidore, the language used by the Sultanate of Tidore, which controlled parts of the islands coastal region. The name came from papo and ua, which means not united or, ploeg reports that the word papua is often said to derive from the Malay word papua or pua-pua, meaning frizzly-haired, referring to the highly curly hair of the inhabitants of these areas. When the Portuguese and Spanish explorers arrived in the island via the Spice Islands, when the Dutch colonized it as part of Netherlands East Indies, they called it Nieuw Guinea. The name Irian was used in the Indonesian language to refer the island and Indonesian province, the name was promoted in 1945 by Marcus Kaisiepo, brother of the future governor Frans Kaisiepo.
It is taken from the Biak language of Biak Island, and means to rise and this name of Irian is the name used in the Biak language and other languages such as Serui and Waropen. The name was used until 2001, when the name Papua was again used for the island, the name Irian, which was originally favored by natives, is now considered to be a name imposed by the authority of Jakarta. New Guinea is an island to the north of Australia, and it is isolated by the Arafura Sea to the west and the Torres Strait and Coral Sea to the east. A spine of east–west mountains, the New Guinea Highlands, dominates the geography of New Guinea, stretching over 1,600 km from the head to the tail of the island. The western half of the island of New Guinea contains the highest mountains in Oceania, rising up to 4,884 m high, the tree line is around 4,000 m elevation and the tallest peaks contain permanent equatorial glaciers—which have been retreating since at least 1936. Various other smaller mountain ranges occur both north and west of the central ranges, except in high elevations, most areas possess a warm humid climate throughout the year, with some seasonal variation associated with the northeast monsoon season.
At 4,884 metres, Puncak Jaya makes New Guinea the worlds fourth highest landmass, Puncak Mandala, located in Papua, is the second highest peak on the island at 4,760 metres. Puncak Trikora, in Papua, is 4,750 metres, mount Wilhelm is the highest peak on the PNG side of the border at 4,509 metres. Its granite peak is the highest point of the Bismarck Range, mount Giluwe 4,368 metres is the second highest summit in PNG. It is the highest volcanic peak in Oceania, another major habitat feature is the vast southern and northern lowlands. Stretching for hundreds of kilometres, these include lowland rainforests, extensive wetlands, savanna grasslands, the southern lowlands are the site of Lorentz National Park, a UNESCO World Heritage Site
Halmahera, formerly known as Jilolo, Gilolo, or Jailolo, is the largest island in the Maluku Islands. It is part of the North Maluku province of Indonesia and Sofifi, the capital of the province, is located on the west coast of the island. Halmahera has an area of 17,780 km2 and a population in 1995 of 162,728. Approximately half of the inhabitants are Muslim and half are Christian. Sparsely-populated Halmaheras fortunes have long been tied to those of the smaller islands of Ternate and Tidore. These islands were both the sites of major kingdoms in the era before Dutch East India Company colonized the entire archipelago, during World War II, Halmahera was the site of a Japanese naval base at Kao Bay. Thousands of people on Halmahera were killed in the fighting between religious militias, in June 2000, about five hundred people were killed when a ferry carrying refugees from the fighting on Halmahera sank off the northeast tip of Sulawesi island. Conspiracy theories about this event abound, a memorial to this tragedy can be found in Duma village in North Halmahera district.
Particularly since the inauguration of the first ever directly elected Bupati, as it is surrounded by flat land, Tobelo has the potential for expansion. Ternate is limited by its size, being an island which can be driven around in forty-five minutes. Also, in 2010 the provincial government has moved the capital from Ternate City to Sofifi. North Maluku Province consists of seven regencies and two municipalities,6 of which include a part of Halmahera island. The regencies are, North Halmahera, West Halmahera, East Halmahera, Central Halmahera, South Hamahera, Ternate Municipality, Tidore City and Islands, only Ternate Municipality and Sula Islands do not include any part of Halmahera. The volcanic island lies on an arc that includes the Raja Ampat Islands, all uplifted by the northward migration of the continent of Australia. Dukono is a volcano at the north end of the island. Mount Ibu is a volcano on the islands northwest coast. The flightless invisible rail is endemic to the island, the naturalist Alfred Russel Wallace visited Halmahera, as described in his 1869 book The Malay Archipelago.
He considered the bird of paradise, Semioptera wallacei, to be his greatest prize
A ridge or mountain ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size, there are several main types of ridges, Dendritic ridge, In typical dissected plateau terrain, the stream drainage valleys will leave intervening ridges. These are by far the most common ridges and these ridges usually represent slightly more erosion resistant rock, but not always – they often remain because there were more joints where the valleys formed, or other chance occurrences. This type of ridge is somewhat random in orientation, often changing direction frequently. Similar ridges have formed in such as the Black Hills. Sometimes these ridges are called hogback ridges, oceanic spreading ridge, In tectonic spreading zones around the world, such as at the Mid-Atlantic Ridge, the volcanic activity forming new plate boundary forms volcanic ridges at the spreading zone.
Isostatic settling and erosion gradually reduce the moving away from the zone. Crater ridges, Large meteorite strikes typically form large impact craters bordered by circular ridges, volcanic crater/caldera ridges, Large volcanoes often leave behind a central crater/caldera bordered by circular ridges. Fault ridges, Faults often form escarpments, sometimes the tops of the escarpments form not plateaus, but slope back so that the edges of the escarpments form ridges. Dune ridges, In areas of large-scale dune activity, certain types of dunes result in sand ridges and eskers, Glacial activity may leave ridges in the form of moraines and eskers. An arête is a ridge of rock that is formed by glacial erosion. Volcanic subglacial ridges, Many subglacial volcanoes create ridge-like formations when lava erupts through a glacier or ice sheet. Shutter ridges, A shutter ridge is a ridge which has moved along a fault line, typically, a shutter ridge creates a valley corresponding to the alignment of the fault that produces it
Western New Guinea
Western New Guinea, formerly known as Irian Jaya, is the Indonesian part of the island of New Guinea, lying to the west of the nation of Papua New Guinea. The territory is considered to include smaller nearby islands including Biak, the region is predominantly dense forest where numerous traditional tribes live such as the Dani of the Baliem Valley, although the majority of the population live in or near coastal areas. The largest city in the region is Jayapura, the official and most commonly spoken language is Indonesian. Estimates of the number of languages in the region range from 200 to over 700, with the most widely spoken including Dani, Ekari. The predominant religion is Christianity followed by Islam, the main industries include agriculture, oil production, and mining. The territory has been part of Indonesia since May 1963, human habitation is estimated to have begun between 42,000 and 48,000 years ago. The Netherlands claimed the region and commenced work in the nineteenth century.
The region was annexed by Indonesia in the 1960s, following the 1998 commencement of reforms across Indonesia and other Indonesian provinces received greater regional autonomy. In 2001, Special Autonomy status was granted to Papua province, although to date, implementation has been partial, the region was administered as a single province until 2003, when it was split into the provinces of Papua and West Papua. Speakers align themselves with a political orientation when choosing a name for the half of the island of New Guinea. West Papua, which is not the name for the western half of the island, is preferred by ethnic Papuans. The region has had the names of Netherlands New Guinea, West New Guinea, West Irian, Irian Jaya. Indonesian president Abdurrahman Wahid considered his use of the name Papua in 2002 as a concession to the West Papuans. Since 2003, western New Guinea has had two provinces, the province of West Papua on the west, and the province of Papua on the east and administrators refer to the province when they say West Papua, independence activists mean the whole of western New Guinea.
The region is 1,200 kilometres from east to west and 736 kilometres from north to south and it has an area of 420,540 square kilometres, which equates to approximately 22% of Indonesias land area. The border with Papua New Guinea mostly follows the 141st meridian east, the island of New Guinea was once part of the Australian landmass and lie on the Sahul. The collision between the Indo-Australian Plate and Pacific plate resulting in the Maoke Mountains run through the centre of the region and are 600 km long and 100 km across. The range includes about ten peaks over 4,000 metres, including Puncak Jaya, Puncak Mandala, the range ensures a steady supply of rain from the tropical atmosphere
The sea has been traditionally used for fishery and transportation of goods between the coastal countries and its coral reefs and islands are popular tourist destinations. The fishery and tourist infrastructure was damaged by the 2004 Indian Ocean earthquake. At its southeastern reaches, the Andaman Sea narrows to form the Straits of Malacca, the International Hydrographic Organization defines the limits of the Andaman or Burma Sea as follows, On the Southwest. The Eastern limit of the Bay of Bengal, a line joining Lem Voalan in Siam, and Pedropunt in Sumatra. The average depth of the sea is about 1,000 meters, the northern and eastern parts are shallower than 180 meters due to the silt deposited by the Irrawaddy River. This major river flows into the sea from the north through Myanmar, the western and central areas are 900–3,000 meters deep. Less than 5% of the sea is deeper than 3,000 meters, and in a system of submarine valleys east of the Andaman-Nicobar Ridge, the sea floor is covered with pebbles and sand.
Running in a rough north–south line on the seabed of the Andaman Sea is the boundary between two plates, the Burma Plate and the Sunda Plate. As a result, a basin center was created, which began to form the marginal basin which would become the Andaman Sea. The boundary between two tectonic plates results in high seismic activity in the region. Numerous earthquakes have been recorded, and at least six, in 1797,1833,1861,2004,2005 and 2007, had the magnitude of 8.4 or higher. On December 26,2004, a portion of the boundary between the Burma Plate and the Indo-Australian Plate slipped, causing the 2004 Indian Ocean earthquake. This megathrust earthquake had a magnitude of 9.3, between 1300 and 1600 kilometers of the boundary underwent thrust faulting and shifted by about 20 meters, with the sea floor being uplifted several meters. This rise in the sea floor generated a tsunami with an estimated height of 28 meters that killed approximately 280,000 people along the coast of the Indian Ocean. The initial quake was followed by a series of aftershocks along the arc of the Andaman, the entire event severely damaged the fishing infrastructure.
Within the sea, to the east of the main Great Andaman island group, lies Barren Island and this island-volcano is 3 km in diameter and rises 354 meters above the sea level. Its recent activity resumed in 1991 after a period of almost 200 years. It is caused by the subduction of the India Plate beneath the Andaman island arc
A drainage basin or catchment area is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. Drainage basins connect into other drainage basins at elevations in a hierarchical pattern, with smaller sub-drainage basins. Other terms used to describe drainage basins are catchment, catchment basin, drainage area, river basin and water basin. In closed drainage basins the water converges to a point inside the basin, known as a sink, which may be a permanent lake. The drainage basin acts as a funnel by collecting all the water within the covered by the basin. Each drainage basin is separated topographically from adjacent basins by a perimeter, drainage basins are similar but not identical to hydrologic units, which are drainage areas delineated so as to nest into a multi-level hierarchical drainage system. Hydrologic units are defined to allow multiple inlets, outlets, or sinks, in a strict sense, all drainage basins are hydrologic units but not all hydrologic units are drainage basins.
Drainage basins of the oceans and seas of the world. Grey areas are endorheic basins that do not drain to the oceans, the following is a list of the major ocean basins, About 48. 7% of the worlds land drains to the Atlantic Ocean. The two major mediterranean seas of the world flow to the Atlantic, The Caribbean Sea and Gulf of Mexico basin includes most of the U. S. The Mediterranean Sea basin includes much of North Africa, east-central Africa, Southern and Eastern Europe and the areas of Israel, Lebanon. Just over 13% of the land in the world drains to the Pacific Ocean, the Indian Oceans drainage basin comprises about 13% of Earths land. It drains the eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf, the Indian subcontinent, antarctica comprises approximately eight percent of the Earths land. The five largest river basins, from largest to smallest, are the basins of the Amazon, the Río de la Plata, the Congo, the Nile, and the Mississippi. The three rivers that drain the most water, from most to least, are the Amazon, endorheic drainage basins are inland basins that do not drain to an ocean.
Around 18% of all land drains to endorheic lakes or seas or sinks, the largest of these consists of much of the interior of Asia, which drains into the Caspian Sea, the Aral Sea, and numerous smaller lakes. Some of these, such as the Great Basin, are not single drainage basins but collections of separate, in endorheic bodies of standing water where evaporation is the primary means of water loss, the water is typically more saline than the oceans. An extreme example of this is the Dead Sea, drainage basins have been historically important for determining territorial boundaries, particularly in regions where trade by water has been important
The Molucca Sea has a total surface area of 77,000 square miles. The Molucca Sea is rich in coral and has many diving sites due to the deepness of its waters, the deepness of the water explains the reasoning behind dividing the sea into three zones, which functions to transport water from the Pacific Ocean to the shallower seas surrounding it. The deepest hollow in the Molucca Sea is the 15, 780-foot Batjan basin, the Molucca Sea borders the Banda Sea to the south and the Celebes Sea to the north. The islands bordering the Molucca Sea include Halmahera to the north east and Ceram in the centre, and Sulawesi to the west. The Talaud Islands to the north are considered to be the border the sea, though the Molucca Sea Plate. The International Hydrographic Organization defines the Molukka Sea as being one of the waters of the East Indian Archipelago, the IHO defines its limits as follows, On the North. By the West coast of Morotai from Tanjong Sopi as far south as Wajaboela, thence a line to the Northern point of Halmahera and down its West coast to Tanjong Libolo, the East coasts of Banggai and Peleng Islands to North Bangkalan thence a line to Tg.
Botok round the coast to Tg, pasir Pandjang and across to Tg. Tombalilatoe on the opposite coast, thence up the East coast to Tg, the Northeastern extreme of Celebes. The Portuguese, Dutch and Spanish Empires fought each other for control of the islands that can only be accessed through the Molucca Sea. The sea is a seismically active area due to the Molucca Sea Plate. Strait of Malacca, which is west of Singapore
It extends 420 miles north-south by 520 mi east-west and has a total surface area of 110,000 square miles, to a maximum depth of 20,300 feet. The sea opens southwest through the Makassar Strait into the Java Sea, the Celebes Sea is a piece of an ancient ocean basin that formed 42 million years ago in a locale removed from any landmass. By 20 million years ago, earth crust movement had moved the basin close enough to the Indonesian and Philippine volcanoes to receive emitted debris. By 10 million years ago the Celebes Sea was inundated with continental debris, including coal, which was shed from a young mountain on Borneo. The border between the Celebes and the Sulu Sea is at the Sibutu-Basilan Ridge, strong ocean currents, deep sea trenches and seamounts, combined with active volcanic islands, result in complex oceanographic features. It has been agreed that north of the line will be under the jurisdiction of the Philippines. The International Hydrographic Organization defines the Celebes Sea as being one of the waters of the East Indian Archipelago, the IHO defines its limits as follows, On the North.
The Southern limit of Sulu Sea and the Southwest coast of Mindanao, a line from Tinaca Point, the Southern point of Mindanao, to the North point of pulau Sangihe Besar thence through the pulau-pulau Sangihe to Tanjung Puisan, the Northeast extreme of Celebes. The North coast of Celebes between tanjung Puisan and tanjung Binar and thence a line to Tanjung Mangkalihat in Borneo, the Northern limit of Makassar Strait, the East coast of Borneo between Tanjung Mangkalihat and Tanjong Labian, the Southern limit of the Sulu Sea. The Celebes Sea is home to a variety of fish. Tuna and yellowfin tuna are abundant, in addition to high abundance of fish caught in the Celebes sea, this sea yields other aquatic products like sea tang. The Celebes Sea is an important sea route for regional trade, the sea is popular for scuba diving and luxury ocean cruising. The Celebes Sea is underlain by a plate with a mid oceanic spreading in the center part. This place is subducted to the south and north, a number of seismic surveys and research drillings were done in this area to gather geological information.
The geology of Sulawesi Sea has been described in the Geology of Indonesia Wikibook, exploring the Inner Space of the Celebes Sea 2007 - A rich collection of images and audio podcast
The Indian Ocean is the third largest of the worlds oceanic divisions, covering 70,560,000 km2. It is bounded by Asia on the north, on the west by Africa, on the east by Australia, the Indian Ocean is known as Ratnākara, the mine of gems in ancient Sanskrit literature, and as Hind Mahāsāgar, in Hindi. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf, the oceans continental shelves are narrow, averaging 200 kilometres in width. An exception is found off Australias western coast, where the width exceeds 1,000 kilometres. The average depth of the ocean is 3,890 m and its deepest point is Diamantina Deep in Diamantina Trench, at 8,047 m deep, Sunda Trench has a depth of 7, 258–7,725 m. North of 50° south latitude, 86% of the basin is covered by pelagic sediments. The remaining 14% is layered with terrigenous sediments, glacial outwash dominates the extreme southern latitudes. The major choke points include Bab el Mandeb, Strait of Hormuz, the Lombok Strait, the Strait of Malacca, the Indian Ocean is artificially connected to the Mediterranean Sea through the Suez Canal, which is accessible via the Red Sea.
All of the Indian Ocean is in the Eastern Hemisphere and the centre of the Eastern Hemisphere is in this ocean, marginal seas, gulfs and straits of the Indian Ocean include, The climate north of the equator is affected by a monsoon climate. Strong north-east winds blow from October until April, from May until October south, in the Arabian Sea the violent Monsoon brings rain to the Indian subcontinent. In the southern hemisphere, the winds are milder. When the monsoon winds change, cyclones sometimes strike the shores of the Arabian Sea, the Indian Ocean is the warmest ocean in the world. Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, Indian Ocean warming is the largest among the tropical oceans, and about 3 times faster than the warming observed in the Pacific. Research indicates that human induced greenhouse warming, and changes in the frequency, among the few large rivers flowing into the Indian Ocean are the Zambezi, Shatt al-Arab, Godavari, Narmada, Brahmaputra and Irrawaddy River.
The oceans currents are controlled by the monsoon. Two large gyres, one in the northern hemisphere flowing clockwise and one south of the equator moving anticlockwise, during the winter monsoon, currents in the north are reversed. Deep water circulation is controlled primarily by inflows from the Atlantic Ocean, the Red Sea, north of 20° south latitude the minimum surface temperature is 22 °C, exceeding 28 °C to the east. Southward of 40° south latitude, temperatures drop quickly, surface water salinity ranges from 32 to 37 parts per 1000, the highest occurring in the Arabian Sea and in a belt between southern Africa and south-western Australia