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122-548: Guadalupe-Nipomo Dunes is the largest remaining dune system south of San Francisco and the second largest in the U.S. state of California . It encompasses an 18-mile (29 km) stretch of coastline on the Central Coast of California and extends from southern San Luis Obispo County to northern Santa Barbara County . The Guadalupe-Nipomo Dunes Complex is home to a unique dunes ecosystem as well as many endangered and threatened species of plants and animals. To protect

244-534: A navy and some form of coast guard . Coasts, especially those with beaches and warm water, attract tourists often leading to the development of seaside resort communities. In many island nations such as those of the Mediterranean , South Pacific Ocean and Caribbean , tourism is central to the economy . Coasts offer recreational activities such as swimming, fishing, surfing, boating, and sunbathing . Growth management and coastal management can be

366-478: A challenge for coastal local authorities who often struggle to provide the infrastructure required by new residents, and poor management practices of construction often leave these communities and infrastructure vulnerable to processes like coastal erosion and sea level rise . In many of these communities, management practices such as beach nourishment or when the coastal infrastructure is no longer financially sustainable, managed retreat to remove communities from

488-619: A combination of factors including beach sand which was blown inland by the wind and the Santa Maria River which brought sediment to the coast. Dune-building began 18,000 years ago with the Nipomo and Orcutt Mesas. This Dune System has the highest dunes on the entire western coastline of the United States. Among these, Mussel Rock Dune is the highest, measuring approximately 500 feet (150 m). Another rare geographic treasure

610-589: A decrease in reproductive success. However, western snowy plover nests have increased dramatically from 16 nests in 1993 to a total of 172 nests in 2011. Memorial Day weekend is one of the park's busiest, and occurs during the plover nesting season. Yet, year after year, large numbers of plover nests are found at nesting sites closest to the open vehicle area at Oceano Dunes, suggesting human presence may deter presence of predators, and that plover may receive refuge at these sites. An eight-year summary of western snowy plover reproduction on California State Park lands depicts

732-562: A dune forms, plant succession occurs. The conditions on an embryo dune are harsh, with salt spray from the sea carried on strong winds. The dune is well drained and often dry, and composed of calcium carbonate from seashells. Rotting seaweed , brought in by storm waves adds nutrients to allow pioneer species to colonize the dune. For example, in the United Kingdom these pioneer species are often marram grass , sea wort grass and other sea grasses. These plants are well adapted to

854-590: A few tens of metres except at their nose, where vegetation stops or slows the advance of accumulating sand. Simple parabolic dunes have only one set of arms that trail upwind, behind the leading nose. Compound parabolic dunes are coalesced features with several sets of trailing arms. Complex parabolic dunes include subsidiary superposed or coalesced forms, usually of barchanoid or linear shapes. Parabolic dunes, like crescent dunes, occur in areas where very strong winds are mostly unidirectional. Although these dunes are found in areas now characterized by variable wind speeds,

976-758: A leash at all times, and rid the beach of trash that could attract predators. During the busy holidays, extra rangers are brought into the park to ensure rules are enforced. For 25 years, the County of San Luis Obispo has leased 584 acres (2.36 km) of the Dunes to the State Department of Parks and Recreation, free of charge. When the lease expired in June 2008, the San Luis Obispo County Board of Supervisors had options, including sale of

1098-407: A low-lying pan within the basin where the water evaporates, depositing the gypsum and forming crystals known as selenite . The crystals left behind by this process are eroded by the wind and deposited as vast white dune fields that resemble snow-covered landscapes. These types of dune are rare, and only form in closed arid basins that retain the highly soluble gypsum that would otherwise be washed into

1220-655: A much higher capacity for carbon sequestration than many terrestrial ecosystems , and as such can play a critical role in the near-future to help mitigate climate change effects by uptake of atmospheric anthropogenic carbon dioxide . However, the economic importance of coasts makes many of these communities vulnerable to climate change , which causes increases in extreme weather and sea level rise, as well as related issues like coastal erosion , saltwater intrusion , and coastal flooding . Other coastal issues, such as marine pollution , marine debris , coastal development, and marine ecosystem destruction, further complicate

1342-653: A proper name to the coast of the Ligurian Sea , in the form riviera ligure , then shortened to riviera . Historically, the Ligurian Riviera extended from Capo Corvo (Punta Bianca) south of Genoa , north and west into what is now French territory past Monaco and sometimes as far as Marseilles . Today, this coast is divided into the Italian Riviera and the French Riviera , although

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1464-435: A provider of sediment for coastlines of tropical islands. Like the ocean which shapes them, coasts are a dynamic environment with constant change. The Earth 's natural processes, particularly sea level rises , waves and various weather phenomena, have resulted in the erosion , accretion and reshaping of coasts as well as flooding and creation of continental shelves and drowned river valleys ( rias ). More and more of

1586-456: A shoreline configuration. Swash is the shoreward flow after the break, backwash is the water flow back down the beach. The relative strength of flow in the swash and backwash determines what size grains are deposited or eroded. This is dependent on how the wave breaks and the slope of the shore. Depending on the form of the breaking wave, its energy can carry granular material up the beach and deposit it, or erode it by carrying more material down

1708-412: A significant role in minimizing wave energy as it moves onshore. As a result, coastal dunes, especially those in the foredune area affected by a storm surge , will retreat or erode. To counteract the damage from tropical activity on coastal dunes, short term post-storm efforts can be made by individual agencies through fencing to help with sand accumulation. How much a dune erodes during any storm surge

1830-425: A slightly different way in discussions of legal and economic boundaries (see territorial waters and international waters ) or when considering the geography of coastal landforms or the ecological systems operating through the continental shelf ( marine coastal ecosystems ). The research on coastal waters often divides into these separate areas too. The dynamic fluid nature of the ocean means that all components of

1952-462: A star dune superimposed on its crest is the most common complex dune. Simple dunes represent a wind regime that has not changed in intensity or direction since the formation of the dune, while compound and complex dunes suggest that the intensity and direction of the wind has changed. The sand mass of dunes can move either windward or leeward, depending on if the wind is making contact with the dune from below or above its apogee. If wind hits from above,

2074-819: A unidirectional wind. In the sheltered troughs between highly developed seif dunes, barchans may be formed, because the wind is constrained to be unidirectional by the dunes. Seif dunes are common in the Sahara. They range up to 300 m (980 ft) in height and 300 km (190 mi) in length. In the southern third of the Arabian Peninsula, a vast erg , called the Rub' al Khali or Empty Quarter, contains seif dunes that stretch for almost 200 km (120 mi) and reach heights of over 300 m (980 ft). Linear loess hills known as pahas are superficially similar. These hills appear to have been formed during

2196-529: A wide range of sessile animals (e.g. mussels , starfish , barnacles ) and various kinds of seaweeds . In physical oceanography , a shore is the wider fringe that is geologically modified by the action of the body of water past and present, while the beach is at the edge of the shore, representing the intertidal zone where there is one. Along tropical coasts with clear, nutrient-poor water, coral reefs can often be found between depths of 1–50 m (3.3–164.0 ft). According to an atlas prepared by

2318-518: Is Oso Flaco Lake, a freshwater lake located amid the Dunes. Even though the Guadalupe-Nipomo Dunes consist of moving sand with extremely low moisture that is seemingly deprived of nutrients, it is home to a variety of flora and fauna . There are at least 18 endangered species of plants living in the Dunes. Dune plants must also be able to endure burial by sand, salt spray, high winds, and high insolation. The Nipomo Mesa lupine

2440-541: Is a coastline that has experienced a fall in sea level, because of either a global sea-level change, or local uplift. Emergent coastlines are identifiable by the coastal landforms , which are above the high tide mark, such as raised beaches . In contrast, a submergent coastline is one where the sea level has risen, due to a global sea-level change, local subsidence , or isostatic rebound . Submergent coastlines are identifiable by their submerged, or "drowned" landforms, such as rias (drowned valleys) and fjords According to

2562-485: Is a type of sandstone that is formed when a marine or aeolian sand dune becomes compacted and hardened. Once in this form, water passing through the rock can carry and deposit minerals, which can alter the colour of the rock. Cross-bedded layers of stacks of lithified dunes can produce the cross-hatching patterns, such as those seen in Zion National Park in the western United States. A slang term, used in

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2684-442: Is a very large aeolian landform, with a length of several kilometers and a height of tens to hundreds of meters, and which may have superimposed dunes. Dunes are made of sand-sized particles, and may consist of quartz, calcium carbonate, snow, gypsum, or other materials. The upwind/upstream/upcurrent side of the dune is called the stoss side; the downflow side is called the lee side. Sand is pushed (creep) or bounces ( saltation ) up

2806-410: Is blown along the beach. Dunes form where the beach is wide enough to allow for the accumulation of wind-blown sand, and where prevailing onshore winds tend to blow sand inland. The three key ingredients for coastal dune formation are a large sand supply, winds to move said sand supply, and a place for the sand supply to accumulate. Obstacles—for example, vegetation, pebbles and so on—tend to slow down

2928-445: Is by saltation , where sand particles skip along the ground like a bouncing ball . When these skipping particles land, they may knock into other particles and cause them to move as well, in a process known as creep . With slightly stronger winds, particles collide in mid-air, causing sheet flows . In a major dust storm , dunes may move tens of metres through such sheet flows. Also as in the case of snow, sand avalanches , falling down

3050-528: Is connected to marine pollution which can occur from a number of sources: Marine debris (garbage and industrial debris); the transportation of petroleum in tankers , increasing the probability of large oil spills ; small oil spills created by large and small vessels, which flush bilge water into the ocean. Marine pollution occurs when substances used or spread by humans, such as industrial , agricultural and residential waste , particles , noise , excess carbon dioxide or invasive organisms enter

3172-709: Is directly in the middle of the Oceano Dunes State Vehicular Recreation area. Various groups and individuals would like to see the land sold to the State Parks. Currently, the Oceano Dunes State Vehicular Recreation Area uses one third of the beach territory for off-road vehicles use. Off-roaders are concerned that since the decision is in the hands of the county, San Luis Obispo County's environmental community may advise more restrictions on

3294-428: Is due to a number of pressures related to their proximity to the ocean and confinement to growth on sandy substrates. These include: Plants have evolved many adaptations to cope with these pressures: In deserts where large amounts of limestone mountains surround a closed basin , such as at White Sands National Park in south-central New Mexico , occasional storm runoff transports dissolved limestone and gypsum into

3416-419: Is endemic to the dunes and is limited to the area. There are five to seven colonies growing in a strip of sand dunes. The dunes are separated into uplands and wetlands habitats. Uplands include the fore dunes, back dunes, and sandy beaches. Dunes can occur in three different formations. Primary Foredunes are parallel to the shore and support sparse vegetation. Parabolic dunes are U-shaped and perpendicular to

3538-415: Is extremely important to geologists. These provide vital clues for reconstructing the geography of ancient continents ( paleogeography ). The locations of these beds show the extent of ancient seas at particular points in geological time, and provide clues to the magnitudes of tides in the distant past. Sediments deposited in the shoreface are preserved as lenses of sandstone in which the upper part of

3660-408: Is more important. Macrotidal coasts lack barrier islands and lagoons , and are characterized by funnel-shaped estuaries containing sand ridges aligned with tidal currents. Wave action is much more important for determining bedforms of sediments deposited along mesotidal and microtidal coasts than in macrotidal coasts. Waves erode coastline as they break on shore releasing their energy; the larger

3782-423: Is moved along the coastline by the waves. This forms an abrasion or cliffed coast . Sediment deposited by rivers is the dominant influence on the amount of sediment located in the case of coastlines that have estuaries. Today, riverine deposition at the coast is often blocked by dams and other human regulatory devices, which remove the sediment from the stream by causing it to be deposited inland. Coral reefs are

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3904-404: Is related to its location on the coastal shoreline and the profile of the beach during a particular season. In those areas with harsher winter weather, during the summer a beach tends to take on more of a convex appearance due to gentler waves, while the same beach in the winter may take on more of a concave appearance. As a result, coastal dunes can get eroded much more quickly in the winter than in

4026-596: Is stimulated to grow by sand burial, causing a positive feedback. Many species of animals can be found among the dunes. Over 200 species of birds live there, such as the western snowy plover , American peregrine falcon , California brown pelican , and California least tern . Other animals also depend on the dunes such as the California red-legged frog , western terrestrial garter snake , mule deer , black bear , bobcats , and mountain lions . Beetles , butterflies , lizards , saltwater and freshwater fish inhabit

4148-412: Is the counterintuitive observation that the coastline of a landmass does not have a well-defined length. This results from the fractal curve –like properties of coastlines; i.e., the fact that a coastline typically has a fractal dimension . Although the "paradox of length" was previously noted by Hugo Steinhaus , the first systematic study of this phenomenon was by Lewis Fry Richardson , and it

4270-462: The Aegean Sea . The following articles describe some coastal landforms: "Coastal waters" (or "coastal seas") is a rather general term used differently in different contexts, ranging geographically from the waters within a few kilometers of the coast, through to the entire continental shelf which may stretch for more than a hundred kilometers from land. Thus the term coastal waters is used in

4392-593: The Sierra Club proposed year-round fencing to protect plover habitat, but the Oceano Dunes State Vehicular Recreation Area rejected the idea. Soon after the decision, a plover was killed by an off-road vehicle in a recommended area for fencing. The Sierra Club sued the State Parks for violating the ESA by not providing enough protection for the snowy plover, as well as the California least tern and steelhead trout. In

4514-456: The US EPA considers this region to extend much further offshore. "Coastal waters" has specific meanings in the context of commercial coastal shipping , and somewhat different meanings in the context of naval littoral warfare . Oceanographers and marine biologists have yet other takes. Coastal waters have a wide range of marine habitats from enclosed estuaries to the open waters of

4636-617: The United Nations , about 44% of the human population lives within 150 km (93 mi) of the sea as of 2013 . Due to its importance in society and its high population concentrations, the coast is important for major parts of the global food and economic system, and they provide many ecosystem services to humankind. For example, important human activities happen in port cities. Coastal fisheries (commercial, recreational, and subsistence) and aquaculture are major economic activities and create jobs, livelihoods, and protein for

4758-523: The Western Desert of Egypt . The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than three kilometres, are in China's Taklamakan Desert . Abundant barchan dunes may merge into barchanoid ridges, which then grade into linear (or slightly sinuous) transverse dunes, so called because they lie transverse, or across, the wind direction, with the wind blowing perpendicular to

4880-686: The Western Interior Seaway , a shallow sea that flooded central North America during the late Cretaceous Period (about 100 to 66 million years ago). These are beautifully exposed along the Book Cliffs of Utah and Colorado . The following articles describe the various geologic processes that affect a coastal zone: Larger animals that live in coastal areas include puffins , sea turtles and rockhopper penguins , among many others. Sea snails and various kinds of barnacles live on rocky coasts and scavenge on food deposited by

5002-469: The ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although marine transportation significantly contributes as well. It is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide. Since most inputs come from land, either via

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5124-596: The ocean . Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing aground, when it is known as beach litter or tidewrack. Deliberate disposal of wastes at sea is called ocean dumping . Naturally occurring debris, such as driftwood and drift seeds , are also present. With the increasing use of plastic , human influence has become an issue as many types of (petrochemical) plastics do not biodegrade quickly, as would natural or organic materials. The largest single type of plastic pollution (~10%) and majority of large plastic in

5246-444: The rivers , sewage or the atmosphere, it means that continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor by carrying off iron, carbonic acid, nitrogen , silicon, sulfur, pesticides or dust particles into the ocean. The pollution often comes from nonpoint sources such as agricultural runoff , wind-blown debris , and dust. These nonpoint sources are largely due to runoff that enters

5368-631: The slipface of the dunes—that face away from the winds—also move the dunes forward. Coastline Coasts are important zones in natural ecosystems , often home to a wide range of biodiversity . On land, they harbor important ecosystems such as freshwater or estuarine wetlands , which are important for bird populations and other terrestrial animals . In wave-protected areas, they harbor salt marshes , mangroves or seagrasses , all of which can provide nursery habitat for fin fish , shellfish , and other aquatic animals . Rocky shores are usually found along exposed coasts and provide habitat for

5490-459: The southwest US , for consolidated and hardened sand dunes is "slickrock", a name that was introduced by pioneers of the Old West because their steel-rimmed wagon wheels could not gain traction on the rock. Sand dunes can have a negative impact on humans when they encroach on human habitats. Sand dunes move via a few different means, all of them helped along by wind. One way that dunes can move

5612-659: The stoss (upflow) side, where the sand is pushed up the dune, and have a shorter slip face in the lee side. The valley or trough between dunes is called a dune slack . Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash , and in other areas where poorly cemented sandstone bedrock disintegrates to produce an ample supply of loose sand. Subaqueous dunes can form from

5734-438: The Dunes and shot a skinny bear by the shores of what is now called Oso Flaco Lake. After eating the bear, two of the explorers became sick. The Chumash had poisoned the skinny bear - as a means of protection, they often incapacitated dangerous wildlife by feeding them tainted meat. This incident resulted in the lake's name: Oso Flaco or "Skinny Bear". In 1923, the epic movie The Ten Commandments directed by Cecil B. DeMille ,

5856-773: The French use the term "Riviera" to refer to the Italian Riviera and call the French portion the "Côte d'Azur". As a result of the fame of the Ligurian rivieras, the term came into English to refer to any shoreline, especially one that is sunny, topographically diverse and popular with tourists. Such places using the term include the Australian Riviera in Queensland and the Turkish Riviera along

5978-728: The San Luis Obispo Board of Supervisors voted 4-0 not to sell the 584 acres (2.36 km) of land to the State. Dune#Coastal dunes A dune is a landform composed of wind- or water-driven sand . It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex . A large dune complex is called a dune field , while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ergs or sand seas . Dunes occur in different shapes and sizes, but most kinds of dunes are longer on

6100-546: The United Nations has declared 2021–2030 the UN Decade on Ecosystem Restoration , but restoration of coastal ecosystems has received insufficient attention. Since coasts are constantly changing, a coastline's exact perimeter cannot be determined; this measurement challenge is called the coastline paradox . The term coastal zone is used to refer to a region where interactions of sea and land processes occur. Both

6222-551: The action of water flow ( fluvial processes) on sand or gravel beds of rivers , estuaries , and the sea-bed. Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach . In most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea . Artificial dunes are sometimes constructed to protect coastal areas. The dynamic action of wind and water can sometimes cause dunes to drift, which can have serious consequences. For example,

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6344-571: The average sea level rose by 15–25 cm (6–10 in), with an increase of 2.3 mm (0.091 in) per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise , with another 42% resulting from thermal expansion of water . International attention to address

6466-417: The average wind wave and swell conditions are relatively mild. Low energy coasts typically change slowly, and tend to be depositional environments. High energy coasts are exposed to the direct impact of waves and storms, and are generally erosional environments. High energy storm events can make large changes to a coastline, and can move significant amounts of sediment over a short period, sometimes changing

6588-568: The breeding success at Oceano Dunes which is particularly stark compared to very low breeding numbers elsewhere in the state. Ecologists argue that the snowy plover does not just breed on any coastal area; they seek protection in the dunes. Scientist Tom Jordan studied data on bird nesting sites and found that snowy plovers "prefer the beach and the flatter areas," such as on top of the dunes, where they can watch for predators. Plovers prefer nesting on open sand which can put nests at risk of being crushed by vehicles or hikers. The Santa Lucia Chapter of

6710-530: The case settlement, the State Park was given the responsibility of researching, fund raising, and establishing an education program about the snowy plover. The Park must close off an additional half-mile of the beach between March and October, the plover's breeding season. Additionally, they must find alternate routes to avoid vehicles crossing the Arroyo Grande Creek because it is inhabited by

6832-461: The coast of Wales and other countries. Coastal fish , also called inshore fish or neritic fish, inhabit the sea between the shoreline and the edge of the continental shelf . Since the continental shelf is usually less than 200 metres (660 ft) deep, it follows that pelagic coastal fish are generally epipelagic fish , inhabiting the sunlit epipelagic zone . Coastal fish can be contrasted with oceanic fish or offshore fish , which inhabit

6954-812: The coast. Estuarine and marine coastal ecosystems are both marine ecosystems . Together, these ecosystems perform the four categories of ecosystem services in a variety of ways: The provisioning services include forest products, marine products, fresh water , raw materials, biochemical and genetic resources. Regulating services include carbon sequestration (contributing to climate change mitigation ) as well as waste treatment and disease regulation and buffer zones. Supporting services of coastal ecosystems include nutrient cycling , biologically mediated habitats and primary production . Cultural services of coastal ecosystems include inspirational aspects, recreation and tourism , science and education. According to one principle of classification, an emergent coastline

7076-409: The coastal environment of the sand dune vital to their species' survival. Over the course of time coastal dunes may be impacted by tropical cyclones or other intense storm activity, dependent on their location. Recent work has suggested that coastal dunes tend to evolve toward a high or low morphology depending on the growth rate of dunes relative to storm frequency. During a storm event, dunes play

7198-608: The concave sides of the dunes. These dunes form under winds that blow consistently from one direction (unimodal winds). They form separate crescents when the sand supply is comparatively small. When the sand supply is greater, they may merge into barchanoid ridges, and then transverse dunes (see below). Some types of crescentic dunes move more quickly over desert surfaces than any other type of dune. A group of dunes moved more than 100 metres per year between 1954 and 1959 in China 's Ningxia Province , and similar speeds have been recorded in

7320-567: The continental shelf. Similarly, the term littoral zone has no single definition. It is the part of a sea , lake , or river that is close to the shore . In coastal environments, the littoral zone extends from the high water mark , which is rarely inundated, to shoreline areas that are permanently submerged . Coastal waters can be threatened by coastal eutrophication and harmful algal blooms . The identification of bodies of rock formed from sediments deposited in shoreline and nearshore environments (shoreline and nearshore facies )

7442-405: The corridors between individual dunes. Because all dune arms are oriented in the same direction, and, the inter-dune corridors are generally swept clear of loose sand, the corridors can usually be traversed in between the trailing arms of the dune. However to cross straight over the dune by going over the trailing arms, can be very difficult. Also, traversing the nose is very difficult as well because

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7564-608: The counties of San Luis Obispo and Santa Barbara, California State Parks , U.S. Fish and Wildlife Service and the Land Conservancy of San Luis Obispo County. The first known inhabitants of the Guadalupe-Nipomo Dunes were Native Americans of the Chumash tribe; early Spanish maritime explorers noted their settlements. However, Europeans did not travel through the Dunes themselves until September 2–4, 1769, when members of Don Gaspar de Portolà 's overland expedition stayed in

7686-555: The deep seas beyond the continental shelves. Many coastal areas are famous for their kelp beds. Kelp is a fast-growing seaweed that can grow up to half a meter a day in ideal conditions. Mangroves , seagrasses , macroalgal beds, and salt marsh are important coastal vegetation types in tropical and temperate environments respectively. Restinga is another type of coastal vegetation. Coasts also face many human-induced environmental impacts and coastal development hazards . The most important ones are: The pollution of coastlines

7808-496: The direction (s) of prevailing winds, are known as lunettes, source-bordering dunes, bourrelets and clay dunes. They may be composed of clay, silt, sand, or gypsum, eroded from the basin floor or shore, transported up the concave side of the dune, and deposited on the convex side. Examples in Australia are up to 6.5 km long, 1 km wide, and up to 50 metres high. They also occur in southern and West Africa , and in parts of

7930-682: The distance between the water line and where vegetation can grow. Coastal dunes can be classified by where they develop, or begin to take shape. Dunes are commonly grouped into either the Primary Dune Group or the Secondary Dune Group. Primary dunes gain most of their sand from the beach itself, while secondary dunes gain their sand from the primary dune. Along the Florida Panhandle, most dunes are considered to be foredunes or hummocks. Different locations around

8052-604: The dune and underlying soils . The stability of the dunes was once attributed to the vegetative cover but recent research has pointed to water as the main source of parabolic dune stability. The vegetation that covers them—grasses, shrubs, and trees—help anchor the trailing arms. In inland deserts, parabolic dunes commonly originate and extend downwind from blowouts in sand sheets only partly anchored by vegetation. They can also originate from beach sands and extend inland into vegetated areas in coastal zones and on shores of large lakes. Most parabolic dunes do not reach heights higher than

8174-513: The dunes and provide horticultural benefits, but instead spread taking land away from native species. Ammophila arenaria , known as European beachgrass, has a similar story, though it has no horticulture benefits. It has great ground coverage and, as intended, stabilized the dunes but as an unintended side effect prevented native species from thriving in those dunes. One such example is the dune field at Point Reyes, California . There are now efforts to get rid of both of these invasive species. As

8296-452: The dunes as well. The dunes have been involved with an ongoing series of environmental debates regarding the reduced air quality found in the receiving towns downwind of the dune system. Physical effects by the dust aerosols are indicated by accounts of homeowners claiming discomfort in breathing during times of high dust concentration, and air quality measurements. The San Luis Obispo County Air Pollution Control District has been researching

8418-466: The dunes environment, much of the Complex has been set aside for conservation. In addition, it is recognized as a National Natural Landmark . Another portion of the Dunes is utilized for recreation, such as camping and off-highway vehicle (OHV) use. The Guadalupe-Nipomo Dunes is owned by a number of federal, state, and local agencies, and private companies, organizations and individuals. These include

8540-517: The dunes shift. Portions of Beyoncé 's Black Is King were filmed on the Dunes in 2019. From the 1920s until the 1940s, a group of mystics, nudists, artists, writers, and hermits known as the "Dunites" inhabited the Dunes. They regarded the Dunes as a center of creative energy. Gavin Arthur founded this art and literature commune and a magazine called "The Dune Forum". At the same time, oil companies had started buying up Dune land, and in 1948 oil

8662-598: The dunes, washing humus into the slacks, and the slacks may be much more developed than the exposed tops of the dunes. It is usually in the slacks that more rare species are developed and there is a tendency for the dune slacks' soil to be waterlogged where only marsh plants can survive. In Europe these plants include: creeping willow, cotton grass, yellow iris , reeds, and rushes. As for vertebrates in European dunes, natterjack toads sometimes breed here. Dune ecosystems are extremely difficult places for plants to survive. This

8784-592: The dunes. Typically these are heather , heaths and gorses . These too are adapted to the low soil water content and have small, prickly leaves which reduce transpiration. Heather adds humus to the soil and is usually replaced by coniferous trees, which can tolerate low soil pH , caused by the accumulation and decomposition of organic matter with nitrate leaching. Coniferous forests and heathland are common climax communities for sand dune systems. Young dunes are called yellow dunes and dunes which have high humus content are called grey dunes . Leaching occurs on

8906-401: The effective winds associated with the growth and migration of both the parabolic and crescent dunes probably are the most consistent in wind direction. The grain size for these well-sorted, very fine to medium sands is about 0.06 to 0.5 mm. Parabolic dunes have loose sand and steep slopes only on their outer flanks. The inner slopes are mostly well packed and anchored by vegetation, as are

9028-519: The geological record . All these dune shapes may occur in three forms: simple (isolated dunes of basic type), compound (larger dunes on which smaller dunes of same type form), and complex (combinations of different types). Simple dunes are basic forms with the minimum number of slipfaces that define the geometric type. Compound dunes are large dunes on which smaller dunes of similar type and slipface orientation are superimposed. Complex dunes are combinations of two or more dune types. A crescentic dune with

9150-595: The globe have dune formations unique to their given coastal profile. Coastal sand dunes can provide privacy and/or habitats to support local flora and fauna. Animals such as sand snakes, lizards, and rodents can live in coastal sand dunes, along with insects of all types. Often the vegetation of sand dunes is discussed without acknowledging the importance that coastal dunes have for animals. Further, some animals, such as foxes and feral pigs can use coastal dunes as hunting grounds to find food. Birds are also known to utilize coastal dunes as nesting grounds. All these species find

9272-638: The ground to avoid the wind and others adopt a Krummholz growth form. The back dunes, just behind the fore dunes, are stabilized and covered with plants. The back dunes are dominated by shrub species like mock heather, dune lupine, coastal buckwheat, and blochman's senecio. The sandy beaches are a harsh environment with no plants able to survive there. The wetlands include the areas that contain water: salt marshes , fresh and brackish-water marshes, swamps , and mudflats . Plants that live there are adapted to dynamic environmental conditions including high salinity concentration and extreme temperatures. Solutions that

9394-408: The harsh conditions of the foredune, typically having deep roots which reach the water table , root nodules that produce nitrogen compounds, and protected stoma , reducing transpiration . Also, the deep roots bind the sand together, and the dune grows into a foredune as more sand is blown over the grasses. The grasses add nitrogen to the soil, meaning other, less hardy plants can then colonize

9516-789: The human uses of the coast and threaten coastal ecosystems. The interactive effects of climate change, habitat destruction , overfishing , and water pollution (especially eutrophication ) have led to the demise of coastal ecosystem around the globe. This has resulted in population collapse of fisheries stocks, loss of biodiversity , increased invasion of alien species , and loss of healthy habitats. International attention to these issues has been captured in Sustainable Development Goal 14 "Life Below Water", which sets goals for international policy focused on preserving marine coastal ecosystems and supporting more sustainable economic practices for coastal communities. Likewise,

9638-429: The land if it isn't sold. Land available for vehicle use has already been reduced from 15,000 acres (61 km) to 1,500 acres (6.1 km). The State wants to buy the land in order to secure a place for off-road vehicles for the future. They claim not all the land would be used for off-road vehicles and camping, and that part of the land would be set aside as preserve areas, as the County wants. On Tuesday April 17, 2007,

9760-457: The land, renewal of the deal with the state or creation of a deal requiring the state to pay rent. To determine whether or not to sell the dune property to the state, two public hearings were held April 17, 2007. To sell real property, four-fifths of the supervisors must vote in favor; but in order to renew a lease only a majority is required. The State Parks offered to pay $ 4.86 million for nearly 584 acres (2.36 km) of beachfront property that

9882-486: The last ice age under permafrost conditions dominated by sparse tundra vegetation. Star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the high center of the mound. They tend to accumulate in areas with multidirectional wind regimes. Star dunes grow upward rather than laterally. They dominate the Grand Erg Oriental of the Sahara. In other deserts, they occur around

10004-410: The majority of coastal human populations. Other coastal spaces like beaches and seaside resorts generate large revenues through tourism . Marine coastal ecosystems can also provide protection against sea level rise and tsunamis . In many countries, mangroves are the primary source of wood for fuel (e.g. charcoal ) and building material. Coastal ecosystems like mangroves and seagrasses have

10126-673: The margins of the continental shelves , make up about 7 percent of the Earth's oceans, but at least 85% of commercially harvested fish depend on coastal environments during at least part of their life cycle. As of October 2010, about 2.86% of exclusive economic zones were part of marine protected areas . The definition of coasts varies. Marine scientists think of the "wet" (aquatic or intertidal ) vegetated habitats as being coastal ecosystems (including seagrass, salt marsh etc.) whilst some terrestrial scientists might only think of coastal ecosystems as purely terrestrial plants that live close to

10248-521: The margins of the sand seas , particularly near topographic barriers. In the southeast Badain Jaran Desert of China, the star dunes are up to 500 metres tall and may be the tallest dunes on Earth. Oval or circular mounds that generally lack a slipface. Dome dunes are rare and occur at the far upwind margins of sand seas. Fixed crescentic dunes that form on the leeward margins of playas and river valleys in arid and semiarid regions in response to

10370-587: The microplastics go through the water filtration system and into the ocean, but because of their small size they are likely to escape capture by the preliminary treatment screens on wastewater plants. These beads are harmful to the organisms in the ocean, especially filter feeders, because they can easily ingest the plastic and become sick. The microplastics are such a concern because it is difficult to clean them up due to their size, so humans can try to avoid using these harmful plastics by purchasing products that use environmentally safe exfoliates. Between 1901 and 2018,

10492-507: The more resistant rocks erode more slowly, remaining as headlands or outcroppings . Parts of a coastline can be categorised as high energy coast or low energy coast. The distinguishing characteristics of a high energy coast are that the average wave energy is relatively high so that erosion of small grained material tends to exceed deposition, and consequently landforms like cliffs, headlands and wave-cut terraces develop. Low energy coasts are generally sheltered from waves, or in regions where

10614-658: The nose is usually made up of loose sand without much if any vegetation. A type of extensive parabolic dune that lacks discernible slipfaces and has mostly coarse grained sand is known as a zibar . The term zibar comes from the Arabic word to describe "rolling transverse ridges ... with a hard surface". The dunes are small, have low relief, and can be found in many places across the planet from Wyoming (United States) to Saudi Arabia to Australia. Spacing between zibars ranges from 50 to 400 metres and they do not become more than 10 metres high. The dunes form at about ninety degrees to

10736-441: The ocean through rivers, but wind-blown debris and dust can also play a role, as these pollutants can settle into waterways and oceans. Pathways of pollution include direct discharge, land runoff, ship pollution , bilge pollution , atmospheric pollution and, potentially, deep sea mining . Marine debris , also known as marine litter, is human-created solid material that has deliberately or accidentally been released in seas or

10858-485: The oceans is discarded and lost nets from the fishing industry. Waterborne plastic poses a serious threat to fish , seabirds , marine reptiles , and marine mammals , as well as to boats and coasts. A growing concern regarding plastic pollution in the marine ecosystem is the use of microplastics. Microplastics are beads of plastic less than 5 millimeters wide, and they are commonly found in hand soaps, face cleansers, and other exfoliators. When these products are used,

10980-443: The plants can take to adapt to high salinity are large tap roots to reach the perched water table, thick cuticle to prevent water loss, and succulence. Weeds have been introduced into the Dunes environment both purposefully and accidentally and threaten the native plant life. Various native plants are being choked out by invasive species like European beach grass. European beach grass achieves higher cover than native dune grass and

11102-440: The prevailing wind which blows away the small, fine-grained sand leaving behind the coarser grained sand to form the crest. Occurring wherever winds periodically reverse direction, reversing dunes are varieties of any of the above shapes. These dunes typically have major and minor slipfaces oriented in opposite directions. The minor slipfaces are usually temporary, as they appear after a reverse wind and are generally destroyed when

11224-596: The reduced air quality downwind of the Oceano Dunes SVRA since 1995, and has concluded that while there is a natural component to the dust pollution, off-highway vehicular activity makes it worse. Off-road vehicle use partially conflicts with habitat of the western snowy plover ( Charadrius nivosus ) which was listed as threatened under the Endangered Species Act (ESA) on March 5, 1993. It is alleged that use by vehicles directly correlates with

11346-484: The resultant direction of sand movement (hence the name "longitudinal"). Some linear dunes merge to form Y-shaped compound dunes. Formation is debated. Ralph Bagnold , in The Physics of Blown Sand and Desert Dunes , suggested that some seif dunes form when a barchan dune moves into a bidirectional wind regime, and one arm or wing of the crescent elongates. Others suggest that seif dunes are formed by vortices in

11468-479: The ridge crest. Seif dunes are linear (or slightly sinuous) dunes with two slip faces. The two slip faces make them sharp-crested. They are called seif dunes after the Arabic word for "sword". They may be more than 160 kilometres (100 miles) long, and thus easily visible in satellite images (see illustrations). Seif dunes are associated with bidirectional winds. The long axes and ridges of these dunes extend along

11590-415: The sand in the dune migrates forward. In plan view, these are U-shaped or V-shaped mounds of well-sorted, very fine to medium sand with elongated arms that extend upwind behind the central part of the dune. There are slipfaces that often occur on the outer side of the nose and on the outer slopes of the arms. These dunes often occur in semiarid areas where the precipitation is retained in the lower parts of

11712-425: The sand particles move leeward; the leeward flux of sand is greater than the windward flux. Conversely, if sand hits from below, sand particles move windward. Further, if the wind is carrying sand particles when it hits the dune, the dune's sand particles will saltate more than if the wind had hit the dune without carrying sand particles. Coastal dunes form when wet sand is deposited along the coast and dries out and

11834-416: The sandstone is coarser than the lower part (a coarsening upwards sequence ). Geologists refer to these are parasequences . Each records an episode of retreat of the ocean from the shoreline over a period of 10,000 to 1,000,000 years. These often show laminations reflecting various kinds of tidal cycles. Some of the best-studied shoreline deposits in the world are found along the former western shore of

11956-438: The sea. A nabkha , or coppice dune, is a small dune anchored by vegetation. They usually indicate desertification or soil erosion, and serve as nesting and burrow sites for animals. Sub-aqueous ( underwater ) dunes form on a bed of sand or gravel under the actions of water flow. They are ubiquitous in natural channels such as rivers and estuaries, and also form in engineered canals and pipelines. Dunes move downstream as

12078-579: The sea. Some coastal animals are used to humans in developed areas, such as dolphins and seagulls who eat food thrown for them by tourists. Since the coastal areas are all part of the littoral zone , there is a profusion of marine life found just off-coast, including sessile animals such as corals , sponges, starfish, mussels, seaweeds, fishes, and sea anemones . There are many kinds of seabirds on various coasts. These include pelicans and cormorants , who join up with terns and oystercatchers to forage for fish and shellfish. There are sea lions on

12200-401: The seashore (see also estuaries and coastal ecosystems ). While there is general agreement in the scientific community regarding the definition of coast, in the political sphere, the delineation of the extents of a coast differ according to jurisdiction . Government authorities in various countries may define coast differently for economic and social policy reasons. The coastline paradox

12322-427: The second principle of classification, a concordant coastline is a coastline where bands of different rock types run parallel to the shore. These rock types are usually of varying resistance , so the coastline forms distinctive landforms, such as coves. Discordant coastlines feature distinctive landforms because the rocks are eroded by the ocean waves . The less resistant rocks erode faster, creating inlets or bay ;

12444-458: The shore with vegetative ridges. Moving sand sheets consist of constantly moving sand, making it hard for vegetation to settle. The fore dunes begin at the high tide line, where only low growing plants with deep root systems (such as sand verbena ) can live. The strong winds, salt spray, and massive amounts of sand make this area uninhabitable for other types of plants. Plants in the dunes adapt growth forms to survive high winds. Some grow close to

12566-404: The slope than up it. Steep waves that are close together and break with the surf plunging down onto the shore slope expend much of their energy lifting the sediment. The weak swash does not carry it far up the slope, and the strong backwash carries it further down the slope, where it either settles in deeper water or is carried along the shore by a longshore current induced by an angled approach of

12688-537: The steelhead trout. Within the Guadalupe-Nipomo Dunes Complex are several distinct regions, each managed by different organizations and used for various purposes. The Oceano State Vehicular Recreation Area has taken measures to protect wildlife by fencing off specific areas from pedestrians and vehicles and creating rules for visitors. Some rules are: adhere to the 15 mph (24 km/h) speed limit, do not enter closed areas, keep dogs on

12810-402: The steeper slip face facing downstream. Ripple marks preserved in sedimentary strata in the geological record can be used to determine the direction of current flow, and thus an indication of the source of the sediments. Dunes on the bed of a channel significantly increase flow resistance, their presence and growth playing a major part in river flooding . A lithified (consolidated) sand dune

12932-604: The stoss side, and slides down the lee side. A side of a dune that the sand has slid down is called a slip face (or slipface). The Bagnold formula gives the speed at which particles can be transported. Five basic dune types are recognized: crescentic, linear, star, dome, and parabolic. Dune areas may occur in three forms: simple (isolated dunes of basic type), compound (larger dunes on which smaller dunes of same type form), and complex (combinations of different types). Barchan dunes are crescent-shaped mounds which are generally wider than they are long. The lee-side slipfaces are on

13054-620: The summer. The converse is true in areas with harsher summer weather. There are many threats to these coastal communities. Some coastal dunes, for example ones in San Francisco, have been completely altered by urbanization; reshaping the dune for human use. This puts native species at risk. Another danger, in California and places in the UK specifically, is the introduction of invasive species. Plant species, such as Carpobrotus edulis , were introduced from South Africa in an attempt to stabilize

13176-758: The terms coast and coastal are often used to describe a geographic location or region located on a coastline (e.g., New Zealand's West Coast , or the East , West , and Gulf Coast of the United States .) Coasts with a narrow continental shelf that are close to the open ocean are called pelagic coast , while other coasts are more sheltered coast in a gulf or bay . A shore , on the other hand, may refer to parts of land adjoining any large body of water, including oceans (sea shore) and lakes (lake shore). The Earth has approximately 620,000 kilometres (390,000 mi) of coastline. Coastal habitats, which extend to

13298-509: The town of Eucla, Western Australia , had to be relocated in the 1890s because of dune drift. The modern word "dune" came into English from French around 1790, which in turn came from Middle Dutch dūne . A universally precise distinction does not exist between ripples, dunes, and draas , which are all deposits of the same type of materials. Dunes are generally defined as greater than 7 cm tall and may have ripples, while ripples are deposits that are less than 3 cm tall. A draa

13420-471: The upstream slope is eroded and the sediment deposited on the downstream or lee slope in typical bedform construction. In the case of sub-aqueous barchan dunes, sediment is lost by their extremities, known as horns. These dunes most often form as a continuous 'train' of dunes, showing remarkable similarity in wavelength and height. The shape of a dune gives information about its formation environment. For instance, rivers produce asymmetrical ripples, with

13542-487: The wave the more energy it releases and the more sediment it moves. 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, and 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

13664-476: The wave-front to the shore. These waves which erode the beach are called destructive waves. Low waves that are further apart and break by spilling , expend more of their energy in the swash which carries particles up the beach, leaving less energy for the backwash to transport them downslope, with a net constrictive influence on the beach. Riviera is an Italian word for "shoreline", ultimately derived from Latin ripa ("riverbank"). It came to be applied as

13786-407: The waves surge up the river estuaries from the ocean. Geologists classify coasts on the basis of tidal range into macrotidal coasts with a tidal range greater than 4 m (13 ft); mesotidal coasts with a tidal range of 2 to 4 m (6.6 to 13 ft); and microtidal coasts with a tidal range of less than 2 m (7 ft). The distinction between macrotidal and mesotidal coasts

13908-534: The western United States, especially Texas. U-shaped mounds of sand with convex noses trailed by elongated arms are parabolic dunes. These dunes are formed from blowout dunes where the erosion of vegetated sand leads to a U-shaped depression. The elongated arms are held in place by vegetation; the largest arm known on Earth reaches 12 km. Sometimes these dunes are called U-shaped, blowout , or hairpin dunes, and they are well known in coastal deserts. Unlike crescent shaped dunes, their crests point upwind. The bulk of

14030-406: The whole ocean system are ultimately connected, although certain regional classifications are useful and relevant. The waters of the continental shelves represent such a region. The term "coastal waters" has been used in a wide variety of different ways in different contexts. In European Union environmental management it extends from the coast to just a few nautical miles while in the United States

14152-402: The wind and lead to the deposition of sand grains. These small "incipient dunes or "shadow dunes" tend to grow in the vertical direction if the obstacle slowing the wind can also grow vertically (i.e., vegetation). Coastal dunes expand laterally as a result of lateral growth of coastal plants via seed or rhizome . Models of coastal dunes suggest that their final equilibrium height is related to

14274-483: The wind next blows in the dominant direction. Draas are very large-scale dune bedforms; they may be tens or a few hundreds of metres in height, kilometres wide, and hundreds of kilometres in length. After a draa has reached a certain size, it generally develops superimposed dune forms. They are thought to be more ancient and slower-moving than smaller dunes, and to form by vertical growth of existing dunes. Draas are widespread in sand seas and are well-represented in

14396-482: The world's people live in coastal regions. According to a United Nations atlas, 44% of all people live within 150 km (93 mi) of the sea. Many major cities are on or near good harbors and have port facilities. Some landlocked places have achieved port status by building canals . Nations defend their coasts against military invaders, smugglers and illegal migrants. Fixed coastal defenses have long been erected in many nations, and coastal countries typically have

14518-668: Was discovered in the Dunes. The oil company Unocal began operating the Guadalupe Oil Field in the 1950s. Over the course of the next forty years, Unocal leaked 18 million gallons of petroleum under the Dunes. In 1994, the company publicly recognized the spill and began cleaning up the 2,700-acre (11 km) site, which lies in San Luis Obispo County immediately north of the Santa Barbara County line. As of 2015, cleanup and restoration work

14640-441: Was expanded upon by Benoit Mandelbrot . Tides often determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, and areas with lower tidal ranges produce deposition at a smaller elevation interval. The tidal range is influenced by the size and shape of the coastline. Tides do not typically cause erosion by themselves; however, tidal bores can erode as

14762-469: Was expected to continue for at least another 10 years. Starting in the 1970s, measures were taken to protect the natural environment at the Dunes. One of the biggest changes was the restriction of OHVs to the designated Oceano Dunes State Vehicular Recreation Area. This allowed for the other areas of the Dunes to undergo restoration efforts by conservation groups. As of 2013 the process of dune restoration continues. The Guadalupe-Nipomo Dunes were formed by

14884-625: Was filmed on the Dunes. At the end of production, the massive sets reproducing ancient Egypt were dismantled and buried on the site to prevent reuse. The location was later used to film the episode "White Tip's Journey" (set in Late Cretaceous Mongolia ) of the dinosaur documentary miniseries Dinosaur Planet in 2004. As of 2013 they remain buried there, despite decades of various proposals for excavation. Some artifacts have been recovered and are on display at The Dunes Visitor Center, while others may be seen from time to time as

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