1.
Wake
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The wake is the region of disturbed flow downstream of a solid body moving through a fluid, caused by the flow of the fluid around the body. Parachutes deployed into wakes suffer dynamic pressure deficits which reduce their expected drag forces, example applications include rocket stage separation and aircraft store separation. In incompressible fluids such as water, a bow wake is created when a watercraft moves through the medium, as the medium cannot be compressed, it must be displaced instead, resulting in a wave. As with all forms, it spreads outward from the source until its energy is overcome or lost. The non-dimensional parameter of interest is the Froude number, waterfowl and boats moving across the surface of water produce a wake pattern, first explained mathematically by Lord Kelvin and known today as the Kelvin wake pattern. This pattern consists of two lines that form the arms of a chevron, V, with the source of the wake at the vertex of the V. For sufficiently slow motion, each line is offset from the path of the wake source by around arcsin =19. 47° and is made up of feathery wavelets angled at roughly 53° to the path. The inside of the V is filled with transverse curved waves and this pattern is independent of the speed and size of the wake source over a significant range of values. However, the changes at high speeds, viz. above a hull Froude number of approximately 0.5. The angles in this pattern are not intrinsic properties of water, Any isentropic. Furthermore, this phenomenon has nothing to do with turbulence, everything discussed here is based on the linear theory of an ideal fluid, cf. Airy wave theory. Parts of the pattern may be obscured by the effects of propeller wash, and tail eddies behind the boats stern, and by the boat being a large object and not a point source. The water need not be stationary, but may be moving as in a river. This formula implies that the velocity of a deep water wave is half of its phase velocity. Two velocity parameters of importance for the pattern are, v is the relative velocity of the water. C is the velocity of a wave, varying with wave frequency. As the surface moves, it continuously generates small disturbances which are the sum of sinusoidal waves with a wide spectrum of wavelengths. Those waves with the longest wavelengths have phase speeds above v, other waves with phase speeds at or below v, however, are amplified through constructive interference and form visible shock waves, stationary in position w. r. t
2.
Elevation
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GIS or geographic information system is a computer system that allows for visualizing, manipulating, capturing, and storage of data with associated attributes. GIS offers better understanding of patterns and relationships of the landscape at different scales, tools inside the GIS allow for manipulation of data for spatial analysis or cartography. A topographical map is the type of map used to depict elevation. In a Geographic Information System, digital models are commonly used to represent the surface of a place. Digital terrain models are another way to represent terrain in GIS, USGS is developing a 3D Elevation Program to keep up with growing needs for high quality topographic data. 3DEP is a collection of enhanced elevation data in the form of high quality LiDAR data over the conterminous United States, Hawaii, there are three bare earth DEM layers in 3DEP which are nationally seamless at the resolution of 1/3,1, and 2 arcseconds. This map is derived from GTOPO30 data that describes the elevation of Earths terrain at intervals of 30 arcseconds and it uses color and shading instead of contour lines to indicate elevation. Hypsography is the study of the distribution of elevations on the surface of the Earth, the term originates from the Greek word ὕψος hypsos meaning height. Most often it is used only in reference to elevation of land, related to the term hypsometry, the measurement of these elevations of a planets solid surface are taken relative to mean datum, except for Earth which is taken relative to the sea level. In the troposphere, temperatures decrease with altitude and this lapse rate is approximately 6.5 °C/km. S
3.
Sierra Nevada (U.S.)
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The Sierra Nevada is a mountain range in the Western United States, between the Central Valley of California and the Basin and Range Province. The vast majority of the lies in the state of California. The Sierra runs 400 miles north-to-south, and is approximately 70 miles across east-to-west, the Sierra is home to three national parks, twenty wilderness areas, and two national monuments. These areas include Yosemite, Sequoia, and Kings Canyon National Parks, the character of the range is shaped by its geology and ecology. More than one hundred years ago during the Nevadan orogeny. The range started to uplift four M. A. ago, the uplift caused a wide range of elevations and climates in the Sierra Nevada, which are reflected by the presence of five life zones. Uplift continues due to faulting caused by forces, creating spectacular fault block escarpments along the eastern edge of the southern Sierra. The Sierra Nevada has a significant history, the California Gold Rush occurred in the western foothills from 1848 through 1855. Due to inaccessibility, the range was not fully explored until 1912, the Sierra Nevada lies in Central and Eastern California, with a very small but historically important spur extending into Nevada. West-to-east, the Sierra Nevadas elevation increases gradually from 1,000 feet in the Central Valley to an height of about 10,500 feet at its crest only 50–75 miles to the east. The east slope forms the steep Sierra Escarpment, unlike its surroundings, the range receives a substantial amount of snowfall and precipitation due to orographic lift. The Sierra Nevada stretches from the Susan River and Fredonyer Pass in the north to Tehachapi Pass in the south and it is bounded on the west by Californias Central Valley and on the east by the Basin and Range Province. The geographical boundary between the Sierra and the Cascades is virtually indistinguishable, with the Fredonyer Pass designation being traditional, physiographically, the Sierra is a section of the Cascade-Sierra Mountains province, which in turn is part of the larger Pacific Mountain System physiographic division. The range is drained on its western slope by the Central Valley watershed, the northern third of the western Sierra is part of the Sacramento River watershed, and the middle third is drained by the San Joaquin River. The eastern slope watershed of the Sierra is much narrower, its rivers flow out into the endorheic Great Basin of eastern California and western Nevada. Although none of the eastern rivers reach the sea, many of the streams from Mono Lake southwards are diverted into the Los Angeles Aqueduct which provides water to Southern California, the height of the mountains in the Sierra Nevada increases gradually from north to south. Between Fredonyer Pass and Lake Tahoe, the range from 5,000 feet to more than 9,000 feet. The crest near Lake Tahoe is roughly 9,000 feet high, farther south, the highest peak in Yosemite National Park is Mount Lyell
4.
Meghalaya
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Meghalaya is a state in northeast India. The name means the abode of clouds in Sanskrit, the population of Meghalaya as of 2016 is estimated to be 3,211,474. Meghalaya covers an area of approximately 22,430 square kilometers, the state is bounded to the south by the Bangladeshi divisions of Mymensingh and Sylhet, to the west by the Bangladeshi division of Rangpur, and to the north and east by Indias State of Assam. The capital of Meghalaya is Shillong, during the British occupation of India, the British imperialist authorities nicknamed it the Scotland of the East. Meghalaya was previously part of Assam, but on 21 January 1972, English is the official language of Meghalaya. The other principal languages spoken include Khasi, Pnar, Hajong, Rabha, Garo, the state is the wettest region of India, recording an average of 12,000 mm of rains a year. About 70% of the state is forested, the Meghalaya subtropical forests ecoregion encompasses the state, its mountain forests are distinct from the lowland tropical forests to the north and south. The forests are notable for their biodiversity of mammals, birds, Meghalaya has predominantly an agrarian economy with a significant commercial forestry industry. The important crops are potatoes, rice, maize, pineapples, bananas, papayas, spices, the service sector is made up of real estate and insurance companies. Meghalayas gross state product for 2012 was estimated at ₹16,173 crore in current prices. The state is rich in minerals, but it has no significant industries. The state has about 1,170 km of national highways and it is also a major logistical center for trade with Bangladesh. Ancient Meghalaya, along with neighboring Indian states, have been of archeological interest, people have lived here since neolithic era. Neolithic sites discovered so far are located in areas of high elevation such as in Khasi Hills, Garo Hills, here neolithic style jhum or shifting cultivation is practiced even today. The highland plateaus fed by abundant rains provided safety from floods, the importance of Meghalaya is its possible role in human history through domestication of rice. The limited archeology done in the hills of Meghalaya suggest human settlement since ancient times, modern history Meghalaya was formed by carving out two districts from the state of Assam, the United Khasi Hills and Jaintia Hills, and the Garo Hills on 21 January 1972. Before attaining full statehood, Meghalaya was given semi-autonomous status in 1970, the Khasi, Garo, and Jaintia tribes had their own kingdoms until they came under British administration in the 19th century. Later, the British incorporated Meghalaya into Assam in 1835, the region enjoyed semi-independent status by virtue of a treaty relationship with the British Crown
5.
Yemen
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Yemen, officially known as the Republic of Yemen, is an Arab country in Western Asia, occupying South Arabia, the southern end of the Arabian Peninsula. Yemen is the second-largest country in the peninsula, occupying 527,970 km2, the coastline stretches for about 2,000 km. It is bordered by Saudi Arabia to the north, the Red Sea to the west, the Gulf of Aden and Arabian Sea to the south, although Yemens constitutionally stated capital is the city of Sanaa, the city has been under rebel control since February 2015. Because of this, Yemens capital has been relocated to the port city of Aden. Yemens territory includes more than 200 islands, the largest of these is Socotra, Yemen was the home of the Sabaeans, a trading state that flourished for over a thousand years and probably also included parts of modern-day Ethiopia and Eritrea. In 275 AD, the region came under the rule of the later Jewish-influenced Himyarite Kingdom, Christianity arrived in the fourth century, whereas Judaism and local paganism were already established. Islam spread quickly in the century and Yemenite troops were crucial in the expansion of the early Islamic conquests. Administration of Yemen has long been notoriously difficult, several dynasties emerged from the ninth to 16th centuries, the Rasulid dynasty being the strongest and most prosperous. The country was divided between the Ottoman and British empires in the twentieth century. The Zaydi Mutawakkilite Kingdom of Yemen was established after World War I in North Yemen before the creation of the Yemen Arab Republic in 1962, South Yemen remained a British protectorate known as the Aden Protectorate until 1967 when it became an independent state and later, a Marxist state. The two Yemeni states united to form the modern republic of Yemen in 1990, Yemen is a developing country, and the poorest country in the Middle East. Under the rule of President Ali Abdullah Saleh, Yemen was described as a kleptocracy, according to the 2009 international corruption Perception Index by Transparency International, Yemen ranked 164 out of 182 countries surveyed. President Saleh stepped down and the powers of the presidency were transferred to Vice President Abd Rabbuh Mansur Hadi, the transitional process was disrupted by conflicts between the Houthis and al-Islah, as well as the al-Qaeda insurgency. In September 2014, the Houthis took over Sanaa, later declaring themselves in control of the government in a coup détat, since then, a Saudi-led intervention has taken place, however, it could not stop the civil war. Instead, the Saudis and the others have destroyed some hospitals, schools and homes, Yemen was mentioned in Old South Arabian inscriptions as Yamnat. In Arabic literature, the term includes much greater territory than that of the republic of Yemen. It stretches from the northern Asir Region in southwestern Saudi Arabia to Dhofar Governorate in southern Oman, one etymology derives Yemen from yumn, meaning felicity, as much of the country is fertile. The Romans called it Arabia Felix, as opposed to Arabia Deserta, al-Yaman significantly plays on the notion of the land to the right, when in Mecca facing the dawn, complementary to Al-Sham, the Land to the Left, referring to the Levant
6.
Western Ghats
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Western Ghats மேற்கு தொடர்ச்சி மலை is a mountain range that runs parallel to the western coast of the Indian peninsula, located entirely in India. It is a UNESCO World Heritage Site and is one of the eight hottest hot-spots of biological diversity in the world and it is sometimes called the Great Escarpment of India. The range runs north to south along the edge of the Deccan Plateau. These hills cover 160,000 km2 and form the catchment area for complex riverine drainage systems that drain almost 40% of India, the Western Ghats block southwest monsoon winds from reaching the Deccan Plateau. The average elevation is around 1,200 m, at least 325 globally threatened species occur in the Western Ghats. The Western Ghats are the mountainous faulted and eroded edge of the Deccan Plateau, geologic evidence indicates that they were formed during the break-up of the supercontinent of Gondwana some 150 million years ago. Geophysical evidence indicates that the west coast of India came into being somewhere around 100 to 80 mya after it broke away from Madagascar, after the break-up, the western coast of India would have appeared as an abrupt cliff some 1,000 m in elevation. Basalt is the predominant rock found in the reaching a thickness of 3 km. Other rock types found are charnockites, granite gneiss, khondalites, leptynites, metamorphic gneisses with detached occurrences of limestone, iron ore. Residual laterite and bauxite ores are found in the southern hills. The Western Ghats extend from the Satpura Range in the north and it traverses south past the states of Maharashtra, Goa, Karnataka and Kerala. Major gaps in the range are the Goa Gap, between the Maharashtra and Karnataka sections, and the Palghat Gap on the Tamil Nadu and Kerala border between the Nilgiri Hills and the Anaimalai Hills. The mountains intercept the rain-bearing westerly monsoon winds, and are consequently an area of high rainfall, particularly on their western side. The northern portion of the coastal plain between the Western Ghats and the Arabian Sea is known as the Konkan, the central portion is called Kanara. The foothill region east of the Ghats in Maharashtra is known as Desh, the range is known as Sahyadri in Maharashtra and Karnataka. The Western Ghats meets the Eastern Ghats at Nilgiris in northwestern Tamil Nadu, Nilgiris connects Biligiriranga Hills in southeastern Karnataka with the Shevaroys and Tirumala hills. In the southern part of the range is Anamudi, the highest peak in Western Ghats, following is a list of some of the highest peaks of the Western Ghats, The Western Ghats form one of the four watersheds of India, feeding the perennial rivers of India. The major river systems originating in the Western Ghats include Godavari, Kaveri, Krishna, Thamiraparani, majority of streams draining the Western Ghats join these rivers and carry large volume of water during the monsoon months
7.
Great Dividing Range
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The Great Dividing Range, or the Eastern Highlands, is Australias most substantial mountain range and the third longest land-based range in the world. The width of the range varies from about 160 km to over 300 km, the Dividing Range does not consist of a single mountain range. It consists of a complex of ranges, plateaus, upland areas and escarpments with an ancient. The physiographic division name for the landmass is called the East Australian Cordillera, in some places the terrain is relatively flat, consisting of very low hills. Typically the highlands range from 300 m to 1,600 m in height, the mountains and plateaus, which consist of limestones, sandstone, quartzite, schists and dolomite, have been created by faulting and folding processes. In the north, the rivers on the west side of the drain towards the Gulf of Carpentaria. The higher and more rugged parts of the range do not necessarily part of the crest of the range. At some places it can be up to 400 km wide, notable ranges and other features which form part of the range complex have their own distinctive names. The Great Dividing Range was formed during the Carboniferous period—over 300 million years ago—when Australia collided with what is now parts of South America, the range has experienced significant erosion since. For tens of thousands of years prior to British colonisation the ranges were home to various Aboriginal Australian nations and clans, evidence remains in some places of their traditional way of life including decorated caves, campsites and trails used to travel between the coastal and inland regions. Many descendants of these still exist today and remain the traditional owners. After British colonisation in 1788, the ranges were an obstacle to exploration, although not high, parts of the highlands were very rugged. Towns in the Blue Mountains were later named each of these men. This was the start of the development of the districts of inland New South Wales. A road was built to Blaxland by convicts within six months, easier routes to inland New South Wales were discovered towards Goulburn to the southwest, and westwards from Newcastle. Subsequent explorations were made across and around the ranges by Allan Cunningham, John Oxley, Hamilton Hume, Paul Edmund Strzelecki, Ludwig Leichhardt and these explorers were mainly concerned with finding and appropriating good agricultural land. By the late 1830s the most fertile rangelands adjacent to the ranges had been explored, appropriated from the traditional inhabitants. These included the Gippsland and Riverina regions in the south, up to the Liverpool Plains, various road and railway routes were subsequently established through many parts of the ranges, although many areas remain remote to this day
8.
New Zealand
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New Zealand /njuːˈziːlənd/ is an island nation in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, or Te Ika-a-Māui, and the South Island, or Te Waipounamu—and around 600 smaller islands. New Zealand is situated some 1,500 kilometres east of Australia across the Tasman Sea and roughly 1,000 kilometres south of the Pacific island areas of New Caledonia, Fiji, because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal, fungal, the countrys varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealands capital city is Wellington, while its most populous city is Auckland, sometime between 1250 and 1300 CE, Polynesians settled in the islands that later were named New Zealand and developed a distinctive Māori culture. In 1642, Dutch explorer Abel Tasman became the first European to sight New Zealand, in 1840, representatives of Britain and Māori chiefs signed the Treaty of Waitangi, which declared British sovereignty over the islands. In 1841, New Zealand became a colony within the British Empire, today, the majority of New Zealands population of 4.7 million is of European descent, the indigenous Māori are the largest minority, followed by Asians and Pacific Islanders. Reflecting this, New Zealands culture is derived from Māori and early British settlers. The official languages are English, Māori and New Zealand Sign Language, New Zealand is a developed country and ranks highly in international comparisons of national performance, such as health, education, economic freedom and quality of life. Since the 1980s, New Zealand has transformed from an agrarian, Queen Elizabeth II is the countrys head of state and is represented by a governor-general. In addition, New Zealand is organised into 11 regional councils and 67 territorial authorities for local government purposes, the Realm of New Zealand also includes Tokelau, the Cook Islands and Niue, and the Ross Dependency, which is New Zealands territorial claim in Antarctica. New Zealand is a member of the United Nations, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development, Pacific Islands Forum, and Asia-Pacific Economic Cooperation. Dutch explorer Abel Tasman sighted New Zealand in 1642 and called it Staten Landt, in 1645, Dutch cartographers renamed the land Nova Zeelandia after the Dutch province of Zeeland. British explorer James Cook subsequently anglicised the name to New Zealand, Aotearoa is the current Māori name for New Zealand. It is unknown whether Māori had a name for the country before the arrival of Europeans. Māori had several names for the two main islands, including Te Ika-a-Māui for the North Island and Te Waipounamu or Te Waka o Aoraki for the South Island. Early European maps labelled the islands North, Middle and South, in 1830, maps began to use North and South to distinguish the two largest islands and by 1907, this was the accepted norm. The New Zealand Geographic Board discovered in 2009 that the names of the North Island and South Island had never been formalised and this set the names as North Island or Te Ika-a-Māui, and South Island or Te Waipounamu
9.
Tasmania
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Tasmania is an island state of the Commonwealth of Australia. It is located 240 km to the south of the Australian mainland, the state encompasses the main island of Tasmania, the 26th-largest island in the world, and the surrounding 334 islands. The state has a population of around 519,100, just over forty percent of which resides in the Greater Hobart precinct, Tasmanias area is 68,401 km2, of which the main island covers 64,519 km2. Though an island state, due to an error the state shares a land border with Victoria at its northernmost terrestrial point, Boundary Islet. The Bishop and Clerk Islets, about 37 km south of Macquarie Island, are the southernmost terrestrial point of the state of Tasmania, the island is believed to have been occupied by Aboriginals for 40,000 years before British colonisation. It is thought Tasmanian Aboriginals were separated from the mainland Aboriginal groups about 10,000 years ago when the sea rose to form Bass Strait. The conflict, which peaked between 1825 and 1831 and led to more than three years of law, cost the lives of almost 1100 Aboriginals and settlers. The near-destruction of Tasmanias Aboriginal population has been described by historians as an act of genocide by the British. The island was part of the Colony of New South Wales. In 1854 the present Constitution of Tasmania was passed and the year the state received permission to change its name to Tasmania. In 1901 it became a state through the process of the Federation of Australia, the state is named after Dutch explorer Abel Tasman, who made the first reported European sighting of the island on 24 November 1642. Tasman named the island Anthony van Diemens Land after his sponsor Anthony van Diemen, the name was later shortened to Van Diemens Land by the British. It was officially renamed Tasmania in honour of its first European discoverer on 1 January 1856, Tasmania was sometimes referred to as Dervon, as mentioned in the Jerilderie Letter written by the notorious Australian bushranger Ned Kelly in 1879. The colloquial expression for the state is Tassie, Tasmania is also colloquially shortened to Tas, especially when used in business names and website addresses. TAS is also the Australia Post abbreviation for the state, the reconstructed Palawa kani language name for Tasmania is Lutriwita. The island was adjoined to the mainland of Australia until the end of the last glacial period about 10,000 years ago, much of the island is composed of Jurassic dolerite intrusions through other rock types, sometimes forming large columnar joints. Tasmania has the worlds largest areas of dolerite, with many distinctive mountains, the central plateau and the southeast portions of the island are mostly dolerite. Mount Wellington above Hobart is an example, showing distinct columns known as the Organ Pipes
