A trail is a path, track or unpaved lane or road. In the United Kingdom and the Republic of Ireland path or footpath is the preferred term for a walking trail; the term is applied, in North America, to routes along rivers, sometimes to highways. In the US, the term was used for a route into or through wild territory used by emigrants. In the USA "trace" is a synonym for trail, as in Natchez Trace; some trails are single use and can only be used for walking, horse riding and cross-country skiing. There are unpaved trails used by dirt bikes and other off-road vehicles and in some places, like the Alps, trails are used for moving cattle and other livestock. In Australia, the term track can be used interchangeably with trail, can refer to anything from a dirt road to an unpaved pedestrian path. In New Zealand, the terms track or walkway are used exclusively except in reference to cross-country skiing: "walkways vary enormously in nature, from short urban strolls, to moderate coastal locations, to challenging tramps in the high country ".
Walkway is used in St. John's, Canada, where the "Grand Concourse", is an integrated walkway system. In the United Kingdom, the term trail is in common usage. Longer distance walking routes, government-promoted long distance paths, collectively known as National Trails, are frequently called ways; the term footpath is preferred for pedestrian routes, including long distance trails, is used for urban paths and sometimes in place of pavement. Track is used for wider paths used for hiking; the terms bridleway, restricted byway are all recognised legal terms and to a greater or lesser extent in general usage. The increased popularity of mountain biking has led to a proliferation of mountain bike trails in many countries; these will be grouped to form larger complexes, known as trail centers. In the early years of the 20th century, the term auto trail was used for a marked highway route, trail is now used to designate routes, including highway routes, designated for tourist interest like the Cabot Trail, Nova Scotia and the Quilt Trails in the US.
The term trail has been used by developers and urban planners for a variety of modern paved roads and boulevards, in these countries, some highways continue to be called a trail, such as the Susquehanna Trail in Pennsylvania, a designation that varies from a two-lane road to a four-lane freeway. A unusual use of the term is in the Canadian province of Alberta, which has multi-lane freeways called trails. Trail segregation, the practice of designating certain trails as having a specific preferred or exclusive use, is common and diverse. For example, bike trails are used not only on roads open to motor vehicles, but in trail systems open to other trail users; some trails are segregated for use by both equestrians and mountain bikes, or by equestrians only, or by mountain bikes only. Designated "wilderness area" trails may be segregated for non-wheeled use. Trail segregation for a particular use is accompanied by prohibitions against that use on other trails within the trail system. Trail segregation may be supported by signage, trail design and construction, by separation between parallel treads.
Separation may be achieved by "natural" barriers including distance, banking and vegetation, by "artificial" barriers including fencing and walls. Bicycle trails encompass a wide variety of trail types, including shared-use paths used for commuting, off-road cross country trails and downhill mountain bike trails; the number of off-road cycle trails has increased along with the popularity of mountain bikes. Off-road bicycle trails are function-specific and most waymarked along their route, they may form part of larger complexes, known as trail centres. Off-road trails incorporate a mix of challenging terrain, smooth fireroads, paved paths. Trails with an easy or moderate technical complexity are deemed cross-country trails, while trails difficult to experienced riders are more dubbed all-mountain, freeride, or downhill. Downhilling is popular at ski resorts such as Mammoth Mountain in California or Whistler Blackcomb in British Columbia, where ski lifts are used to get bikes and riders to the top of the mountain.
EuroVelo bicycle routes are a network of long-distance cycling routes criss-crossing Europe in various stages of completion, more than 45,000 km was in place by 2013. It is envisaged that the network will be complete by 2020 and when finished, the EuroVelo network's total length will exceed 70,000 km. EuroVelo is a project of the European Cyclists' Federation. EuroVelo routes can be used for bicycle touring across the continent, as well as by local people making short journeys; the routes are made of both existing national bike routes, such as the Dutch LF-Routes, the German D-Routes, the British National Cycle Network, existing general purpose roads, together with new stretches of cycle routes to connect them. Off-road cycling can cause soil erosion and habitat destruction if not carried out on established trails; this is so when trails are wet, overall though, cycling may have only as mu
A zip line consists of a pulley suspended on a cable made of stainless steel, mounted on a slope. It is designed to enable cargo or a person propelled by gravity to travel from the top to the bottom of the inclined cable by holding on to or being attached to the moving pulley, it has been described as a Tyrolean traverse that engages gravity to assist its speed of movement. Its use is not confined to adventure sport, play or tourism, but current usage tends to favour these meanings. Ropeways or aerial cables have been used as a method of transport in some mountainous countries for more than 2,000 years starting in China and Japan as early as 250 BC, remaining in use in some remote areas in China such as Nujiang valley in Yunnan as late as 2015 before being replaced by bridges. Not all of these structures were assisted by gravity, so not all fitted the definition of the zip-line. Various technological advances in Europe in the Middle Ages improved the ropeways, some of which were still assisted by gravity.
The first recorded use of the zip-line as a form of entertainment was in 1739, when Robert Cadman, a steeplejack and ropeslider, died when descending from Shrewsbury's St Mary’s Church when his rope snapped. In literature, one appears in The Invisible Man by H. G. Wells as part of a Whit Monday fair and referred to as "an inclined strong"; some sources attribute the development of zip-lines used today as a vacation activity to the Tyrolean traverses developed for mountaineering purposes. In the Australian outback, zip-lines were sometimes used for delivering necessities to people working in or on the other side of a valley, they may have been used in conflicts by Australian troops to deliver food and ammunition to forward positions. Yungas, features a system of zip-lines used for transporting harvested crops coca, across a valley 200m below, they can be seen in the Ladakh region of India. In recent years, there has been renewed interest in the use of aerial ropeways for transporting cargo due to their low energy requirements and environmental impact.
Gravity-fed types, i.e. zip-lines, have been built in Latin America and India. Zip-lines may be found on some adventure playgrounds. Inclines are shallow and so the speeds kept low, negating the need for a means of stopping; the term "flying fox" is used in reference to such a small-scale zip-line in Australia and New Zealand. With playground equipment, the pulleys are fixed to the cable, the user hanging onto a hand grip underneath but including a seat or a safety strap. Return of the grip or seat is done by pushing or pulling via a short wire it back to the top of the hill on foot. Longer and higher rides are used as a means of accessing remote areas, such as a rainforest canopy. In the 1970s, wildlife biologists set up zip-lines as a way to study and explore the dense rainforests of Costa Rica without disturbing the environment; the business idea for zip-line canopy tours developed from these. Darren Hreniuk, a Canadian citizen who moved to Costa Rica in 1992, around the same time that a scene in the film Medicine Man incorporated the treetop rides, with the goal of using canopy tours to help raise awareness for reforestation and socio-economic development in the surrounding areas.
In October 1998, the Costa Rican Patent Office granted patent No. 2532 for an “Elevated Forest Transport System Propelled by Gravity, Using Harness and Pulley Through a Simple Horizontal Line” to Hreniuk. The patent was annulled and brought uncertainty to zip-line businesses, before being reinstated after 20 years. A canopy tour provides a route through a wooded and mountainous landscape making primary use of zip-lines and aerial bridges between platforms built in trees. Tourists are harnessed to a cable for safety, many are restricted to adults. Heights vary from a close to the ground to high up near the treetops. Canopy tours are marketed under the banner of ecotourism, although the environmental impact of any type of zip-line is a disputed topic; the terminology varies and the line between using zip-lines for ecotourism and zip-lining as an adventure sport is not drawn. Zip-line tours are now popular vacation activities, found at both upscale resorts and outdoor adventure camps, where they may be an element on a larger challenge such as a hike or ropes course.
A type of pulley with a grooved wheel known as a sheave is used in zip-lines, the pulley turns as it travels along, thus reducing friction and enabling greater speed than would otherwise be possible. The zip-line trolley is the frame or assembly together with the pulley inside that run along the cable. Zip-lines have some kind of device to allow the cargo or rider take advantage of the pulley system; this could include a harness, seat, a cabin or just a handhold in smaller playground applications, that attaches to the pulley by a pivoting link or carabiner which secures the load, allowing the person or cargo to travel down the line. To be propelled by gravity, the cable needs to be on a steep slope; the rider or cargo will not travel to the end, some means of safely stopping the car at the bottom end is needed with the larger zip-lines. Users of zip-lines must have means of stopping themselves. Typical mechanisms include: Friction created between the pulley against the cable. Thick, purpos
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. A sill is a concordant intrusive sheet, meaning that a sill does not cut across preexisting rock beds. Stacking of sills builds a large magma chamber at high magma flux. In contrast, a dike is a discordant intrusive sheet. Sills are fed by dikes, except in unusual locations where they form in nearly vertical beds attached directly to a magma source; the rocks must be brittle and fracture to create the planes along which the magma intrudes the parent rock bodies, whether this occurs along preexisting planes between sedimentary or volcanic beds or weakened planes related to foliation in metamorphic rock. These planes or weakened areas allow the intrusion of a thin sheet-like body of magma paralleling the existing bedding planes, concordant fracture zone, or foliations. Sills parallel beds and foliations in the surrounding country rock.
They can be emplaced in a horizontal orientation, although tectonic processes may cause subsequent rotation of horizontal sills into near vertical orientations. Sills can be confused with solidified lava flows. Intruded sills will show partial incorporation of the surrounding country rock. On both contact surfaces of the country rock into which the sill has intruded, evidence of heating will be observed. Lava flows will show this evidence only on the lower side of the flow. In addition, lava flows will show evidence of vesicles where gases escaped into the atmosphere; because sills form at shallow depths below the surface, the pressure of overlying rock prevents this from happening much, if at all. Lava flows will typically show evidence of weathering on their upper surface, whereas sills, if still covered by country rock do not. Certain layered intrusions are a variety of sill that contain important ore deposits. Precambrian examples include the Bushveld and the Great Dyke complexes of southern Africa, the Duluth intrusive complex of the Superior District, the Stillwater igneous complex of the United States.
Phanerozoic examples are smaller and include the Rùm peridotite complex of Scotland and the Skaergaard igneous complex of east Greenland. These intrusions contain concentrations of gold, platinum and other rare elements. Despite their concordant nature, many large sills change stratigraphic level within the intruded sequence, with each concordant part of the intrusion linked by short dike-like segments; such sills are known as transgressive, examples include the Whin Sill and sills within the Karoo basin. The geometry of large sill complexes in sedimentary basins has become clearer with the availability of 3D seismic reflection data; such data has shown that many sills have an overall saucer shape and that many others are at least in part transgressive. Aquatic sill Batholith Dike Laccolith Sheet intrusion Sill swarm Stock
A boardwalk is an elevated footpath, walkway, or causeway built with wooden planks that enables pedestrians to cross wet, fragile, or marshy land. They are in effect a low type of bridge; such timber trackways have existed since at least Neolithic times. An early example is the Sweet Track that Neolithic people built in the Somerset levels, around 6000 years ago; this track consisted of planks of oak laid end-to-end, supported by crossed pegs of ash and lime, driven into the underlying peat. The Wittmoor bog trackway is the name given to each of two prehistoric plank roads, or boardwalks, trackway No. I being discovered in trackway No. II in 1904 in the Wittmoor bog in northern Hamburg, Germany; the trackways date to the 4th and 7th century AD, both linked the eastern and western shores of the inaccessible, swampy bog. A part of the older trackway No. II dating to the period of the Roman Empire is on display at the permanent exhibition of the Archaeological Museum Hamburg in Harburg, Hamburg. A duckboard is a type of boardwalk placed over wet ground.
During World War I, duckboards were used to line the bottom of trenches on the Western Front, as these were flooded, mud and water would lie in the trenches for months on end. The boards helped to keep the soldiers' feet dry and prevent the development of trench foot, caused by prolonged standing in waterlogged conditions, they allowed for troops' easier movement through the trench systems. Combat troops on nearly all sides wore hobnail style "Trench Boots" that slipped on the new duck boards when they were wet, required extra caution. Falling or slipping off the duckboards could be dangerous fatal. Unfortunate soldiers were left struggling to rise under the weight of their equipment in the intractable and sometimes deep water or mud. If this happened at ground level during a tactical advance, the rising soldier could be left a defenseless target for enemy fire as well as hinder forward progress, he could simply go unnoticed in the ensuing melee, drown under his heavy equipment. Many waterfront commercial boardwalks in the United States have become so successful as tourist attractions that the simple wooden pathways have been replaced by esplanades made of concrete, brick or other construction, sometimes with a wooden facade on the surface and sometimes not.
One of the earliest such boardwalks was designed in New Jersey and opened June 26, 1870, in Atlantic City. Media related to Duckboards at Wikimedia Commons
In earth science, erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust, transports it to another location. This natural process is caused by the dynamic activity of erosive agents, that is, ice, air, plants and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind erosion, zoogenic erosion, anthropogenic erosion; the particulate breakdown of rock or soil into clastic sediment is referred to as physical or mechanical erosion. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Natural rates of erosion are controlled by the action of geological weathering geomorphic drivers, such as rainfall; the rates at which such processes act control. Physical erosion proceeds fastest on steeply sloping surfaces, rates may be sensitive to some climatically-controlled properties including amounts of water supplied, wind speed, wave fetch, or atmospheric temperature.
Feedbacks are possible between rates of erosion and the amount of eroded material, carried by, for example, a river or glacier. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, which control the arrival and emplacement of material at a new location. While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the natural rate of erosion in the region. Excessive erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses.
Water and wind erosion are the two primary causes of land degradation. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, gully erosion. Splash erosion is seen as the first and least severe stage in the soil erosion process, followed by sheet erosion rill erosion and gully erosion. In splash erosion, the impact of a falling raindrop creates a small crater in the soil, ejecting soil particles; the distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs.
If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are of the order of a few centimetres or less and along-channel slopes may be quite steep; this means that rills exhibit hydraulic physics different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and flows in narrow channels during or after heavy rains or melting snow, removing soil to a considerable depth. Valley or stream erosion occurs with continued water flow along a linear feature; the erosion is both downward, deepening the valley, headward, extending the valley into the hillside, creating head cuts and steep banks.
In the earliest stage of stream erosion, the erosive activity is dominantly vertical, the valleys have a typical V cross-section and the stream gradient is steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain; the stream gradient becomes nearly flat, lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far the most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone
Dorion is a township in the Canadian province of Ontario, located within the Thunder Bay District. The township had a population of 338 in the Canada 2011 Census. Ouimet Canyon and the Dorion Bible Camp are located in the community. Population trend: Population in 2006: 379 Population in 2001: 442 Population in 1996: 472 Population in 1991: 513 List of townships in Ontario
A glacier is a persistent body of dense ice, moving under its own weight. Glaciers deform and flow due to stresses induced by their weight, creating crevasses and other distinguishing features, they abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets in the polar regions, but glaciers may be found in mountain ranges on every continent including Oceania's high-latitude oceanic island countries such as New Zealand and Papua New Guinea. Between 35°N and 35°S, glaciers occur only in the Himalayas, Rocky Mountains, a few high mountains in East Africa, New Guinea and on Zard Kuh in Iran. Glaciers cover about 10 percent of Earth's land surface. Continental glaciers cover nearly 13 million km2 or about 98 percent of Antarctica's 13.2 million km2, with an average thickness of 2,100 m.
Greenland and Patagonia have huge expanses of continental glaciers. Glacial ice is the largest reservoir of fresh water on Earth. Many glaciers from temperate and seasonal polar climates store water as ice during the colder seasons and release it in the form of meltwater as warmer summer temperatures cause the glacier to melt, creating a water source, important for plants and human uses when other sources may be scant. Within high-altitude and Antarctic environments, the seasonal temperature difference is not sufficient to release meltwater. Since glacial mass is affected by long-term climatic changes, e.g. precipitation, mean temperature, cloud cover, glacial mass changes are considered among the most sensitive indicators of climate change and are a major source of variations in sea level. A large piece of compressed ice, or a glacier, appears blue, as large quantities of water appear blue; this is. The other reason for the blue color of glaciers is the lack of air bubbles. Air bubbles, which give a white color to ice, are squeezed out by pressure increasing the density of the created ice.
The word glacier is a loanword from French and goes back, via Franco-Provençal, to the Vulgar Latin glaciārium, derived from the Late Latin glacia, Latin glaciēs, meaning "ice". The processes and features caused by or related to glaciers are referred to as glacial; the process of glacier establishment and flow is called glaciation. The corresponding area of study is called glaciology. Glaciers are important components of the global cryosphere. Glaciers are categorized by their morphology, thermal characteristics, behavior. Cirque glaciers form on the slopes of mountains. A glacier that fills a valley is called a valley glacier, or alternatively an alpine glacier or mountain glacier. A large body of glacial ice astride a mountain, mountain range, or volcano is termed an ice cap or ice field. Ice caps have an area less than 50,000 km2 by definition. Glacial bodies larger than 50,000 km2 are called continental glaciers. Several kilometers deep, they obscure the underlying topography. Only nunataks protrude from their surfaces.
The only extant ice sheets are the two that cover most of Greenland. They contain vast quantities of fresh water, enough that if both melted, global sea levels would rise by over 70 m. Portions of an ice sheet or cap that extend into water are called ice shelves. Narrow, fast-moving sections of an ice sheet are called ice streams. In Antarctica, many ice streams drain into large ice shelves; some drain directly into the sea with an ice tongue, like Mertz Glacier. Tidewater glaciers are glaciers that terminate in the sea, including most glaciers flowing from Greenland, Antarctica and Ellesmere Islands in Canada, Southeast Alaska, the Northern and Southern Patagonian Ice Fields; as the ice reaches the sea, pieces break off, or calve. Most tidewater glaciers calve above sea level, which results in a tremendous impact as the iceberg strikes the water. Tidewater glaciers undergo centuries-long cycles of advance and retreat that are much less affected by the climate change than those of other glaciers.
Thermally, a temperate glacier is at melting point throughout the year, from its surface to its base. The ice of a polar glacier is always below the freezing point from the surface to its base, although the surface snowpack may experience seasonal melting. A sub-polar glacier includes both temperate and polar ice, depending on depth beneath the surface and position along the length of the glacier. In a similar way, the thermal regime of a glacier is described by its basal temperature. A cold-based glacier is below freezing at the ice-ground interface, is thus frozen to the underlying substrate. A warm-based glacier is above or at freezing at the interface, is able to slide at this contact; this contrast is thought to a large extent to govern the ability of a glacier to erode its bed, as sliding ice promotes plucking at rock from the surface below. Glaciers which are cold-based and warm-based are known as polythermal. Glaciers form where the accumulation of ice exceeds ablation. A glacier originates from a landform called'cirque' – a armchair-shaped geological feature (such as a depressio