Sand is a granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than coarser than silt. Sand can refer to a textural class of soil or soil type; the composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica in the form of quartz. The second most common type of sand is calcium carbonate, for example, created, over the past half billion years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Sand is a non-renewable resource over human timescales, sand suitable for making concrete is in high demand. Desert sand, although plentiful, is not suitable for concrete, 50 billion tons of beach sand and fossil sand is needed each year for construction; the exact definition of sand varies.
The scientific Unified Soil Classification System used in engineering and geology corresponds to US Standard Sieves, defines sand as particles with a diameter of between 0.074 and 4.75 millimeters. By another definition, in terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm to 2 mm. An individual particle in this range size is termed a sand grain. Sand grains are between silt; the size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. The grains of sand in Archimedes Sand Reckoner written around 240 BCE, were 0.02 mm in diameter. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A 1938 specification of the United States Department of Agriculture was 0.05 mm. Sand feels gritty when rubbed between the fingers.
Silt, by comparison, feels like flour). ISO 14688 grades sands as fine and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is divided into five sub-categories based on size: fine sand, fine sand, medium sand, coarse sand, coarse sand; these sizes are based on the Krumbein phi scale, where size in Φ = -log2D. On this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers; the most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica in the form of quartz, because of its chemical inertness and considerable hardness, is the most common mineral resistant to weathering. The composition of mineral sand is variable, depending on the local rock sources and conditions; the bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material, suggesting sand formation depends on living organisms, too.
The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a granitic rock outcrop; some sands contain magnetite, glauconite or gypsum. Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are green in color, as are sands derived from basaltic lava with a high olivine content. Many sands those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones. Rocks erode/weather over a long period of time by water and wind, their sediments are transported downstream; these sediments continue to break apart into smaller pieces. The type of rock the sediment originated from and the intensity of the environment gives different compositions of sand.
The most common rock to form sand is Granite, where the Feldspar minerals dissolve faster than the Quartz, causing the rock to break apart into small pieces. In high energy environments rocks break apart much faster than in more calm settings. For example, Granite rocks this means more Feldspar minerals in the sand because it wouldn't have had time to dissolve; the term for sand formed by weathering is epiclastic. Sand from rivers are collected either from the river itself or its flood plain, accounts for the majority of the sand used in the construction industry; because if this, many small rivers have been depleted, causing environmental concern and economic losses to adjacent land. The rate of sand mining in such areas outweighs the rate the sand can replenish, making it a non-renewable resource. Sand dunes are a consequence of wind deposition; the Sahara Desert is dry because of its geographic location and is known for its vast sand dunes. They exist here because little vegetation is able to grow and there's not a lot of water.
Over time, wind blow
The South Island officially named Te Waipounamu, is the larger of the two major islands of New Zealand in surface area. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean; the South Island covers 150,437 square kilometres. It has a temperate climate, it has a 32 percent larger landmass than the North Island, as a result is nicknamed the "mainland" of New Zealand by South Island residents, but only 23 percent of New Zealand's 4.9 million inhabitants live there. In the early stages of European settlement of the country, the South Island had the majority of the European population and wealth due to the 1860s gold rushes; the North Island population overtook the South in the early 20th century, with 56 percent of the population living in the North in 1911, the drift north of people and businesses continued throughout the century. In the 19th century, some maps named the South Island as Middle Island or New Munster, the name South Island or New Leinster was used for today's Stewart Island/Rakiura.
In 1907 the Minister for Lands gave instructions to the Land and Survey Department that the name Middle Island was not to be used in future. "South Island will be adhered to in all cases". Although the island had been known as the South Island for many years, in 2009 the New Zealand Geographic Board found that, along with the North Island, the South Island had no official name. After a public consultation, the board named the island South Island or Te Waipounamu in October 2013. Said to mean "the Water of Greenstone", this name evolved from Te Wāhi Pounamu "the Place Of Greenstone"; the island is known as Te Waka a Māui which means "Māui's Canoe". In some Māori legends, the South Island existed first, as the boat of Maui, while the North Island was the fish that he caught. In prose, the two main islands of New Zealand are called the North Island and the South Island, with the definite article, it is normal to use the preposition in rather than on, for example "Christchurch is in the South Island", "my mother lives in the South Island".
Maps, headings and adjectival expressions use South Island without "the". Charcoal drawings can be found on limestone rock shelters in the centre of the South Island, with over 500 sites stretching from Kaikoura to North Otago; the drawings are estimated to be between 500 and 800 years old, portray animals and fantastic creatures stylised reptiles. Some of the birds pictured are long extinct, including Haast's eagles, they were drawn by early Māori, but by the time Europeans arrived, local Māori did not know the origins of the drawings. Early inhabitants of the South Island were the Waitaha, they were absorbed via marriage and conquest by the Kāti Māmoe in the 16th century. Kāti Māmoe were in turn absorbed via marriage and conquest by the Kāi Tahu who migrated south in the 17th century. While today there is no distinct Kāti Māmoe organisation, many Kāi Tahu have Kāti Māmoe links in their whakapapa and in the far south of the island. Around the same time a group of Māori migrated to Rekohu, where, in adapting to the local climate and the availability of resources, they evolved into a separate people known as the Moriori with its own distinct language — related to the parent culture and language in mainland New Zealand.
One notable feature of the Moriori culture, an emphasis on pacifism, proved disadvantageous when Māori warriors arrived in the 1830s aboard a chartered European ship. In the early 18th century, Kāi Tahu, a Māori tribe who originated on the east coast of the North Island, began migrating to the northern part of the South Island. There they and Kāti Māmoe fought Ngāi Rangitāne in the Wairau Valley. Ngāti Māmoe ceded the east coast regions north of the Clarence River to Kāi Tahu. Kāi Tahu continued conquering Kaikoura. By the 1730s, Kāi Tahu had settled including Banks Peninsula. From there they spread further south and into the West Coast. In 1827-1828 Ngāti Toa under the leadership of Te Rauparaha attacked Kāi Tahu at Kaikoura. Ngāti Toa visited Kaiapoi, ostensibly to trade; when they attacked their hosts, the well-prepared Kāi Tahu killed all the leading Ngāti Toa chiefs except Te Rauparaha. Te Rauparaha returned to his Kapiti Island stronghold. In November 1830 Te Rauparaha persuaded Captain John Stewart of the brig Elizabeth to carry him and his warriors in secret to Akaroa, where by subterfuge they captured the leading Kāi Tahu chief, Te Maiharanui, his wife and daughter.
After destroying Te Maiharanui's village they killed them. John Stewart, though arrested and sent to trial in Sydney as an accomplice to murder escaped conviction. In the summer of 1831–32 Te Rauparaha attacked the Kaiapoi pā. Kaiapoi was engaged in a three-month siege by Te Rauparaha, during which his men sapped the pā, they attacked Kāi Tahu on Banks Peninsula and took the pā at Onawe. In 1832-33 Kāi Tahu retaliated under the leadership of Tūhawaiki and others, attacking Ngāti Toa at Lake Grassmere. Kāi Tahu prevailed, killed many Ngāti Toa, although Te Rauparaha again escaped. Fighting continued with Kāi Tahu maintaining the upper hand. Ngāti Toa never again made a major incursion into Kāi Tahu territory. By 1839 Kāi Tahu and Ngāti Toa established peace and Te Rauparaha released the Kāi Tahu captives he held. Formal marriages between the leading families in the two tribes sealed the peace; the first Europeans known to reach the South Island were the crew o
The coast known as the coastline or seashore, is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox; the term coastal zone is a region where interaction of the land processes occurs. Both the terms coast and coastal are used to describe a geographic location or region. Edinburgh for example is a city on the coast of Great Britain. A pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the other hand, can refer to parts of land adjoining any large body of water, including oceans and lakes; the somewhat related term "" refers to the land alongside or sloping down to a river or body of water smaller than a lake. "Bank" is used in some parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. While many scientific experts might agree on a common definition of the term "coast", the delineation of the extents of a coast differ according to jurisdiction, with many scientific and government authorities in various countries differing for economic and social policy reasons.
According to the UN atlas, 44% of people live within 150 kilometres of the sea. Tides determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, areas with lower tidal ranges produce deposition at a smaller elevation interval; the tidal range is influenced by the shape of the coastline. Tides do not cause erosion by themselves. Waves erode coastline. Coastlines with longer shores have more room for the waves to disperse their energy, while coasts with cliffs and short shore faces give little room for the wave energy to be dispersed. In these areas the wave energy breaking against the cliffs is higher, air and water are compressed into cracks in the rock, forcing the rock apart, breaking it down. Sediment deposited by waves comes from eroded cliff faces and is moved along the coastline by the waves; this forms an cliffed coast. Sediment deposited by rivers is the dominant influence on the amount of sediment located on a coastline.
Today riverine deposition at the coast is blocked by dams and other human regulatory devices, which remove the sediment from the stream by causing it to be deposited inland. Like the ocean which shapes them, coasts are a dynamic environment with constant change; the Earth's natural processes sea level rises and various weather phenomena, have resulted in the erosion and reshaping of coasts as well as flooding and creation of continental shelves and drowned river valleys. The coast and its adjacent areas on and off shore are an important part of a local ecosystem: the mixture of fresh water and salt water in estuaries provides many nutrients for marine life. Salt marshes and beaches support a diversity of plants and insects crucial to the food chain; the high level of biodiversity creates a high level of biological activity, which has attracted human activity for thousands of years. More and more of the world's people live in coastal regions. Many major cities have port facilities; some landlocked places have achieved port status by building canals.
The coast is a frontier that nations have defended against military invaders and illegal migrants. Fixed coastal defenses have long been erected in many nations and coastal countries have a navy and some form of coast guard. Coasts those with beaches and warm water, attract tourists. In many island nations such as those of the Mediterranean, South Pacific and Caribbean, tourism is central to the economy. Coasts offer recreational activities such as swimming, surfing and sunbathing. Growth management can be a challenge for coastal local authorities who struggle to provide the infrastructure required by new residents. Coasts face many human-induced environmental impacts; the human influence on climate change is thought to contribute to an accelerated trend in sea level rise which threatens coastal habitats. Pollution can occur from a number of sources: industrial debris. Fishing has declined due to habitat degradation, trawling and climate change. Since the growth of global fishing enterprises after the 1950s, intensive fishing has spread from a few concentrated areas to encompass nearly all fisheries.
The scraping of the ocean floor in bottom dragging is devastating to coral and other long-lived species that do not recover quickly. This destruction alters the functioning of the ecosystem and can permanently alter species composition and biodiversity. Bycatch, the capture of unintended species in the course of fishing, is returned to the ocean only to die from injuries or exposure. Bycatch represents about a quarter of all marine catch. In the case of shrimp capture, the bycatch is five times larger, it is believed that melting Arctic ice will cause sea levels to rise and flood coas
Bahrain the Kingdom of Bahrain, is an island country in the Persian Gulf. The sovereign state comprises a small archipelago centered around Bahrain Island, situated between the Qatar peninsula and the north eastern coast of Saudi Arabia, to which it is connected by the 25-kilometre King Fahd Causeway. Bahrain's population is 1,234,571, including 666,172 non-nationals, it is 765.3 square kilometres in size, making it the third-smallest nation in Asia after the Maldives and Singapore. Bahrain is the site of the ancient Dilmun civilisation, it has been famed since antiquity for its pearl fisheries, which were considered the best in the world into the 19th century. Bahrain was one of the earliest areas to convert to Islam, in 628 CE. Following a period of Arab rule, Bahrain was occupied by the Portuguese in 1521, who in turn were expelled in 1602 by Shah Abbas I of the Safavid dynasty under the Persian Empire. In 1783, the Bani Utbah clan captured Bahrain from Nasr Al-Madhkur and it has since been ruled by the Al Khalifa royal family, with Ahmed al Fateh as Bahrain's first hakim.
In the late 1800s, following successive treaties with the British, Bahrain became a protectorate of the United Kingdom. In 1971, Bahrain declared independence. An emirate, the Arab constitutional monarchy of Bahrain was declared a kingdom in 2002. In 2011, the country experienced protests inspired by the regional Arab Spring. Bahrain's ruling al-Khalifa royal family has been accused and criticized for human rights abuses, including imprisonment and execution of dissidents, political opposition figures and its Shia Muslim population. Bahrain had the first post-oil economy in the Persian Gulf. Since the late 20th century, Bahrain has invested in the tourism sectors. Many large financial institutions have a presence in the country's capital, it is recognised by the World Bank as a high-income economy. Bahrain is a member of the United Nations, Non-Aligned Movement, Arab League, Organisation of Islamic Cooperation and the Gulf Cooperation Council. Bahrayn is the dual form of Arabic bahr, so al-Bahrayn means "the two seas".
However, the name has been lexicalised as a feminine proper noun and does not follow the grammatical rules for duals. Endings are added to the word with no changes, as in the name of the national anthem Bahraynunā or the demonym Bahraynī; the mediaeval grammarian al-Jawahari commented on this saying that the more formally correct term Bahrī would have been misunderstood and so was unused. It remains disputed which "two seas" the name Bahrayn refers to; the term appears five times in the Quran, but does not refer to the modern island—originally known to the Arabs as Awal—but, rather, to all of Eastern Arabia. Today, Bahrain's "two seas" are taken to be the bay east and west of the island, the seas north and south of the island, or the salt and fresh water present above and below the ground. In addition to wells, there are areas of the sea north of Bahrain where fresh water bubbles up in the middle of the salt water as noted by visitors since antiquity. An alternate theory with regard to Bahrain's toponymy is offered by the al-Ahsa region, which suggests that the two seas were the Great Green Ocean and a peaceful lake on the Arabian mainland.
Until the late Middle Ages, "Bahrain" referred to the region of Eastern Arabia that included Southern Iraq, Kuwait, Al-Hasa and Bahrain. The region stretched from Basra in Iraq to the Strait of Hormuz in Oman; this was Iqlīm al-Bahrayn's "Bahrayn Province". The exact date at which the term "Bahrain" began to refer to the Awal archipelago is unknown; the entire coastal strip of Eastern Arabia was known as "Bahrain" for a millennium. The island and kingdom were commonly spelled Bahrein into the 1950s. Bahrain was home to Dilmun, an important Bronze Age trade centre linking Mesopotamia and the Indus Valley. Bahrain was ruled by the Assyrians and Babylonians. From the sixth to third century BCE, Bahrain was part of the Achaemenid Empire. By about 250 BCE, Parthia brought the Persian Gulf under its control and extended its influence as far as Oman; the Parthians established garrisons along the southern coast of the Persian Gulf to control trade routes. During the classical era, Bahrain was referred to by the ancient Greeks as Tylos, the centre of pearl trading, when the Greek admiral Nearchus serving under Alexander the Great landed on Bahrain.
Nearchus is believed to have been the first of Alexander's commanders to visit the island, he found a verdant land, part of a wide trading network. The use of these is not confined to India, but extends to Arabia." The Greek historian Theophrastus states that much of Bahrain was covered by these cotton trees and that Bahrain was famous for exporting walking canes engraved with emblems that were customarily carried in Babylon. Alexander had planned to settle Greek colonists on Bahrain, although it is not clear that this happened on the scale he envisaged, Bahrain became much part of the Hellenised world: the language of the upper classes was Greek, while Zeus was worshipped in the form of the Arabian sun-god Shams. Bahrain became the site of
Alby is a village on the Baltic Sea in the Hulterstad district at the western fringe of the Stora Alvaret on the island of Öland, Sweden. Archaeological evidence indicates this settlement to have been one of the oldest on the island of Öland, with excavations, dating to the paleolithic era, showing the presence of hunter-gatherers; the village prehistory dates to the early Stone Age when settlers from the mainland migrated across the ice bridge connecting the island via the Kalmar Strait about 6000 to 7000 BC. These early inhabitants are known in the archaeological literature as the Alby People. In the earliest times villagers subsisted by hunting and gathering, but by 4000 BC farming supplanted that lifestyle, continues to the year 2006 to be the primary livelihood; the village lies atop the low lying north-south coastal ridge that defines the separation of the coastal plain from the Stora Alvaret. Alby is situated along the two-lane east coast highway, with the communities of Hulterstad and Triberga to the south.
Alby is a component of the Stora Alvaret, designated as a World Heritage Site by UNESCO due to its extraordinary biodiversity and prehistory. Alby is bounded on the east by the Baltic Sea and on the west by the Stora Alvaret, an expansive limestone barren. Alby is situated on the southeastern coast of the island of Öland and is bisected by the two lane Sweden Route 136, the main perimeter highway of the island. Öland is Sweden's second largest island and is located in the Baltic Sea off of the southeast Swedish mainland. Further south on Highway 136 lie the villages of Hulterstad; the village of Stagerstad is found two kilometers to the north on the perimeter highway. The closest sizable city is Färjestaden, situated 25 kilometers to the northwest at the Öland Bridge landing on the Öland side. Other vicinity landmarks are the ancient royal game reserve at Ottenby, found at the southern tip of the island about 30 kilometers to the south and the Eketorp fortress, a restored Iron Age ringfort, lying 21 kilometers south.
Bedrock layers are Ordovician limestone that dates to at least 600 million years ago. Most of the limited supply of topsoil was created from glacial grinding of the limestone bedrock, which action created the nearly flat alvar formation, it was the end of the last ice age which led to uplift, creating the landform, now the island of Öland. The village of Alby, as well as the precursor civilizations from Stone Age to medieval time, is developed on a narrow ridge running north/south parallel to the Baltic coast; this ridge is the only place along the eastern coast that soil extends more than the two centimeter maximum of the Stora Alvaret. The ridge was formed by wave action during the post-Ice Age uplift. Therefore, this thicker soil layer provided the only hospitable place for building foundations, burial grounds and agriculture; the earliest settlers built early Stone Age wooden huts at the fringe of a prehistoric lagoon at the northwest of the present Alby. Archaeological excavations conducted over a period of years in the latter 20th century have revealed evidence of bear, marten and porpoise, but elucidate mesolithic hunting and gathering technologies through discovery of bone spears, moose antler harpoons and flint.
These earliest inhabitants would have crossed the Kalmar Strait from the mainland toward the end of the last Ice Age, before the glacial cap had melted, thus provided an ice bridge. The settlers at Alby are referred to as the Alby People in the archaeological literature, the Alby mesolithic village is one of the key resources that led to the UNESCO designation of the Stora Alvaret as a World Heritage Site; the principal evidence of life in the Alby area from 1000 BC to 1000 AD is derived from the Hulterstad district grave fields south of Alby. The Hulterstad Gravfeld is situated to the east of the coast highway and contains undulating barrows comprising over 170 individual burials, making it one of the largest gravefields on Öland; these burials span Iron Age and Viking periods. The wavy terrain is characteristic of Iron Age barrows, there are numerous standing stones present. Numerous artefacts have been recovered from this gravefield, including bronze chains and a bone needle case. Viking graves have been found at the Hulterstad Gravefield as well as the extensive Strandvalle Gravfeld a few kilometers further south.
These findings imply that Alby was a link within a chain of Viking settlements concentrated on the southeast coast of Öland. Seafaring Viking cultures seemed to prefer the eastern side of the island more due to the good beaches and ample forestation. While little recorded information exists for this period, Viking interments are dated to the High Middle Ages. By royal decree, detailed church records began to be kept by the latter 17th century in the form of births, deaths and annual household censuses. For the entire Hulterstad district, these archives were prepared and maintained at the Hulterstad Church; these records form a basis of estimating the population and lifespans of Alby residents at the end of the 17th century, since the records of Alby were kept distinct from other villages within the Hulterstad district. The late 17th century village population has been estimated at 35 to 60 individuals with life expectancy 45 years; the oldest surviving buildings in Alby date to the 16th century.
Zrće is a long pebble beach on the Adriatic island of Pag in the northern part of the Croatian coast. It is located near about 2 kilometres from the town's center, it is one of over 100 Blue Flag beaches in Croatia, having been given the award in 2003. The beach is a Croatian summer destination for partygoers, with several all-hours discotheques and beach bars operating during summer months, it features house, EDM, hardstyle, r'n'b, hip-hop and trance DJs at the peak of the Croatian summer season from May till the end of August. Zrće Beach has three clubs: Aquarius and Papaya, the Noa club is located nearby on Katarelac beach. Activities include bungee jet-ski, party boats and inflatable catapults. Jaz Beach, Budva Riviera, Montenegro Rana e Hedhun, Albania Dhermi, Albanian Riviera, Albania Zrce Beach Tourist Board of Novalja
A landform is a natural feature of the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, their arrangement in the landscape is known as topography. Typical landforms include hills, plateaus and valleys, as well as shoreline features such as bays and seas, including submerged features such as mid-ocean ridges and the great ocean basins. Landforms are categorized by characteristic physical attributes such as elevation, orientation, rock exposure, soil type. Gross physical features or landforms include intuitive elements such as berms, hills, cliffs, rivers, peninsulas and numerous other structural and size-scaled elements including various kinds of inland and oceanic waterbodies and sub-surface features. Oceans and continents exemplify the highest-order landforms. Landform elements are parts of a high-order landforms that can be further identified and systematically given a cohesive definition such as hill-tops, saddles and backslopes; some generic landform elements including: pits, channels, passes and plains.
Terrain is the vertical dimension of land surface. Topography is the study of terrain, although the word is used as a synonym for relief itself; when relief is described underwater, the term bathymetry is used. In cartography, many different techniques are used to describe relief, including contour lines and TIN. Elementary landforms are the smallest homogeneous divisions of the land surface, at the given scale/resolution; these are areas with homogeneous morphometric properties, bounded by lines of discontinuity. A plateau or a hill can be observed at various scales ranging from few hundred meters to hundreds of kilometers. Hence, the spatial distribution of landforms is scale-dependent as is the case for soils and geological strata. A number of factors, ranging from plate tectonics to erosion and deposition, can generate and affect landforms. Biological factors can influence landforms— for example, note the role of vegetation in the development of dune systems and salt marshes, the work of corals and algae in the formation of coral reefs.
Landforms do not include man-made features, such as canals and many harbors. Many of the terms are not restricted to refer to features of the planet Earth, can be used to describe surface features of other planets and similar objects in the Universe. Examples are mountains, polar caps, valleys, which are found on all of the terrestrial planets; the scientific study of landforms is known as geomorphology. Landforms may be extracted from a digital elevation model using some automated techniques where the data has been gathered by modern satellites and stereoscopic aerial surveillance cameras; until compiling the data found in such data sets required time consuming and expensive techniques involving many man-hours. The most detailed DEMs available are measured directly using LIDAR techniques. Landforms portal Geomorphology Land List of landforms Open-geomorphometry project Terrain Open-Geomorphometry Project