1.
Glacier terminus
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A glacier terminus, toe, or snout, is the end of a glacier at any given point in time. Although glaciers seem motionless to the observer, in reality glaciers are in endless motion, the position of a glacier terminus is also impacted by localized or regional temperature change over time. Tracking the change in location of a terminus is a method of monitoring a glaciers movement. The end of the terminus is measured from a fixed position in neighboring bedrock periodically over time. The difference in location of a terminus as measured from this fixed position at different time intervals provides a record of the glaciers change. A similar way of tracking glacier change is comparing photographs of the position at different times. The form of a terminus is determined by many factors. If the glacier is retreating, it is usually mildly sloping in form because a melting glacier tends to assume this shape. The photograph above shows the glacial lakes formed by the glacial termini on the surface of the debris-covered glaciers over the last several decades in the Bhutan-Himalaya region
2.
Alaska
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Alaska is a U. S. state located in the northwest extremity of North America. To the north are the Chukchi and Beaufort seas–the southern parts of the Arctic Ocean, the Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous, approximately half of Alaskas residents live within the Anchorage metropolitan area. Alaskas economy is dominated by the fishing, natural gas, military bases and tourism are also a significant part of the economy. The United States purchased Alaska from the Russian Empire on March 30,1867, the area went through several administrative changes before becoming organized as a territory on May 11,1912. It was admitted as the 49th state of the U. S. on January 3,1959, the name Alaska was introduced in the Russian colonial period when it was used to refer to the peninsula. It was derived from an Aleut, or Unangam idiom, which refers to the mainland of Alaska. Literally, it means object to which the action of the sea is directed, Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere. Alaska is the only non-contiguous U. S. state on continental North America and it is technically part of the continental U. S. but is sometimes not included in colloquial use, Alaska is not part of the contiguous U. S. often called the Lower 48. The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system. Alaskas territorial waters touch Russias territorial waters in the Bering Strait, as the Russian Big Diomede Island, Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the area of the next three largest states, Texas, California, and Montana. It is also larger than the area of the 22 smallest U. S. states. Also referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States, as such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase. The region is dominated by the Alexander Archipelago as well as the Tongass National Forest and it contains the state capital Juneau, the former capital Sitka, and Ketchikan, at one time Alaskas largest city. The Alaska Marine Highway provides a vital transportation link throughout the area. The Interior is the largest region of Alaska, much of it is uninhabited wilderness, Fairbanks is the only large city in the region
3.
Kenai Fjords National Park
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Kenai Fjords National Park is a United States National Park established in 1980 by the Alaska National Interest Lands Conservation Act. The park covers an area of 669,984 acres on the Kenai Peninsula in southcentral Alaska, the park contains the Harding Icefield, one of the largest ice fields in the United States. The park is named for the numerous fjords carved by glaciers moving down the mountains from the ice field, the field is the source of at least 38 glaciers, the largest of which is Bear Glacier. The park lies just to the west of Seward, a port for cruise ships. Exit Glacier is reachable by road and is a tour destination. The remainder of the park is accessible by boat. The fjords are glacial valleys that have been submerged below sea level by a combination of rising sea levels, establishment as a national park followed the passage of the Alaska National Interest Lands Conservation Act in 1980. The park protects the icefield, a fringe of forested land between the mountains and the sea, and the deeply indented coastline. The park is home to a variety of terrestrial and marine mammals, including bears, whales, seals. Kenai Fjords National Park was established in 1980 by the Alaska National Interest Lands Conservation Act and it is a relatively small and accessible park by Alaskan national park standards, about 88% as big as Yosemite National Park. It is the fifth most-visited park in Alaska, but the 11th of 13 Alaska parks in area, the parks headquarters is in Seward. At the time of the establishment, there were few permanent inhabitants. Archeological surveys have altered the view that the area was subject to only transient occupation as evidence has accumulated of long-term use. It is believed that coastal subsidence and rising water levels have inundated many sites, a 1993 Park Service survey documented several village sites dated between 1200 AD and 1920. The survey also found evidence that an earthquake dating to about 1170 AD lowered the shoreline by at least 1.8 metres, a 2003 follow-up survey indicated that one site was occupied between 950 AD and 1800. Another site was used from 1785 to 1820, a third site showed occupancy from 1850 to 1890. Several gold mines from historical times have been documented in the park, mining activity centered on Nuka Bay. Some sites had been active into the 1980s, eleven mine sites have been documented and two of the mine sites have been determined to be eligible for the National Register of Historic Places
4.
Himalayas
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The Himalayas, or Himalaya, form a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau. The Himalayan range has the Earths highest peaks, including the highest, the Himalayas include over a hundred mountains exceeding 7,200 metres in elevation. By contrast, the highest peak outside Asia – Aconcagua, in the Andes – is 6,961 metres tall. The Himalayas are spread across five countries, Bhutan, India, Nepal, China, the Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the major rivers, the Indus, the Ganges, and the Tsangpo-Brahmaputra, rise in the Himalayas. The Himalayas have profoundly shaped the cultures of South Asia, many Himalayan peaks are sacred in Hinduism and Buddhism. Lifted by the subduction of the Indian tectonic plate under the Eurasian Plate and its western anchor, Nanga Parbat, lies just south of the northernmost bend of Indus river. Its eastern anchor, Namcha Barwa, is just west of the bend of the Tsangpo river. The range varies in width from 400 kilometres in the west to 150 kilometres in the east, the name of the range derives from the Sanskrit Himā-laya, from himá and ā-laya. They are now known as the Himalaya Mountains, usually shortened to the Himalayas, formerly, they were described in the singular as the Himalaya. This was also previously transcribed Himmaleh, as in Emily Dickinsons poetry and Henry David Thoreaus essays. The mountains are known as the Himālaya in Nepali and Hindi, the Himalaya or The Land of Snow in Tibetan, the Hamaleh Mountain Range in Urdu, the flora and fauna of the Himalayas vary with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice, the amount of yearly rainfall increases from west to east along the southern front of the range. This diversity of altitude, rainfall and soil conditions combined with the high snow line supports a variety of distinct plant. The extremes of high altitude combined with extreme cold favor extremophile organisms, the unique floral and faunal wealth of the Himalayas is undergoing structural and compositional changes due to climate change. The increase in temperature is shifting various species to higher elevations, the oak forest is being invaded by pine forests in the Garhwal Himalayan region. There are reports of early flowering and fruiting in some species, especially rhododendron, apple. The highest known tree species in the Himalayas is Juniperus tibetica located at 4,900 metres in Southeastern Tibet, the Himalayan range is one of the youngest mountain ranges on the planet and consists mostly of uplifted sedimentary and metamorphic rock
5.
Mount Everest
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Mount Everest, also known in Nepal as Sagarmāthā and in China as Chomolungma/珠穆朗玛峰, is Earths highest mountain. Its peak is 8,848 metres above sea level, Mount Everest is in the Mahalangur Range. The international border between China and Nepal runs across Everests summit point and its massif includes neighbouring peaks Lhotse,8,516 m, Nuptse,7,855 m, and Changtse,7,580 m. In 1856, the Great Trigonometrical Survey of India established the first published height of Everest, then known as Peak XV, at 8,840 m. The current official height of 8,848 m as recognised by China and Nepal was established by a 1955 Indian survey, in 2005, China remeasured the height of the mountain and got a result of 8844.43 m. An argument regarding the height between China and Nepal lasted five years from 2005 to 2010, China argued it should be measured by its rock height which is 8,844 m but Nepal said it should be measured by its snow height 8,848 m. In 2010, an agreement was reached by both sides that the height of Everest is 8,848 m and Nepal recognises Chinas claim that the rock height of Everest is 8,844 m. In 1865, Everest was given its official English name by the Royal Geographical Society upon a recommendation by Andrew Waugh, the British Surveyor General of India. As there appeared to be several different local names, Waugh chose to name the mountain after his predecessor in the post, Sir George Everest, Mount Everest attracts many climbers, some of them highly experienced mountaineers. There are two main climbing routes, one approaching the summit from the southeast in Nepal and the other from the north in Tibet, as of 2016 there are well over 200 corpses on the mountain, with some of them even serving as landmarks. The first recorded efforts to reach Everests summit were made by British mountaineers, with Nepal not allowing foreigners into the country at the time, the British made several attempts on the north ridge route from the Tibetan side. Tragedy struck on the descent from the North Col when seven porters were killed in an avalanche. They had been spotted high on the mountain that day but disappeared in the clouds, never to be seen again, Tenzing Norgay and Edmund Hillary made the first official ascent of Everest in 1953 using the southeast ridge route. Tenzing had reached 8,595 m the previous year as a member of the 1952 Swiss expedition, the Chinese mountaineering team of Wang Fuzhou, Gonpo, and Qu Yinhua made the first reported ascent of the peak from the north ridge on 25 May 1960. In 1802, the British began the Great Trigonometric Survey of India to fix the locations, heights, starting in southern India, the survey teams moved northward using giant theodolites, each weighing 500 kg and requiring 12 men to carry, to measure heights as accurately as possible. They reached the Himalayan foothills by the 1830s, but Nepal was unwilling to allow the British to enter the country due to suspicions of political aggression, several requests by the surveyors to enter Nepal were turned down. The British were forced to continue their observations from Terai, a region south of Nepal which is parallel to the Himalayas, conditions in Terai were difficult because of torrential rains and malaria. Three survey officers died from malaria while two others had to retire because of failing health, nonetheless, in 1847, the British continued the survey and began detailed observations of the Himalayan peaks from observation stations up to 240 km distant
6.
Snow
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Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets, snowflakes take on a variety of shapes, basic among these are platelets, needles, columns and rime. As snow accumulates into a snowpack, it may blow into drifts, over time, accumulated snow metamorphoses, by sintering, sublimation and freeze-thaw. Where the climate is cold enough for year-to-year accumulation, a glacier may form, otherwise, snow typically melts seasonally, causing runoff into streams and rivers and recharging groundwater. Major snow-prone areas include the regions, the upper half of the Northern Hemisphere and mountainous regions worldwide with sufficient moisture. In the Southern Hemisphere, snow is confined primarily to mountainous areas, Snow affects ecosystems, as well, by providing an insulating layer during winter under which plants and animals are able to survive the cold. Snow develops in clouds that themselves are part of a weather system. The physics of snow crystal development in clouds results from a set of variables that include moisture content. The resulting shapes of the falling and fallen crystals can be classified into a number of shapes and combinations. Occasionally, some plate-like, dendritic and stellar-shaped snowflakes can form under clear sky with a cold temperature inversion present. Two additional and locally productive sources of snow are lake-effect storms and elevation effects, miid-latitude cyclones are low pressure areas which are capable of producing anything from cloudiness and mild snow storms to heavy blizzards. During a hemispheres fall, winter, and spring, the atmosphere over continents can be cold enough through the depth of the troposphere to cause snowfall, in the Northern Hemisphere, the northern side of the low pressure area produces the most snow. For the southern mid-latitudes, the side of a cyclone that produces the most snow is the southern side, a cold front, the leading edge of a cooler mass of air, can produce frontal snowsqualls—an intense frontal convective line, when temperature is near freezing at the surface. The strong convection that develops has enough moisture to produce whiteout conditions at places which line passes over as the wind causes intense blowing snow. This type of snowsquall generally lasts less than 30 minutes at any point along its path, in cases where there is a large amount of vertical growth and mixing the squall may develop embedded cumulonimbus clouds resulting in lightning and thunder which is dubbed thundersnow. A warm front can produce snow for a period, as warm, moist air overrides below-freezing air, often, snow transitions to rain in the warm sector behind the front. The same effect occurs over bodies of salt water, when it is termed ocean-effect or bay-effect snow. The effect is enhanced when the air mass is uplifted by the orographic influence of higher elevations on the downwind shores
7.
Snowpack
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Snowpack forms from layers of snow that accumulate in geographic regions and high altitudes where the climate includes cold weather for extended periods during the year. Snowpacks are an important water resource that feed streams and rivers as they melt, therefore, snowpacks are both the drinking water source for many communities and a potential source of flooding. Snowpacks also contribute mass to glaciers in their accumulation zone, assessing the formation and stability of snowpacks is important in the study and prediction of avalanches. Snow is also studied in a global context of impact on animal habitats. An important effort is put into snow classification, both as an hydrometeor and on the ground, snowpack modeling is done for snow stability, flood forecasting, water resource management, and climate studies. Snowpack modeling is either done by simple, statistical methods such as day or complex, physically based energy balance models such as the SNOWPACK model. Advection Glaciation Glacier mass balance Hydrology Subnivean climate SNOWPACK CROCUS SnowModel
8.
Rockslide
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A rockslide is a type of landslide caused by rock failure in which part of the bedding plane of failure passes through intact rock and material collapses en masse and not in individual blocks. While a landslide occurs when loose dirt or sediment falls down a slope, the rocks tumble downhill, loosening other rocks on their way and smashing everything in their path. Fast-flowing rock slides or debris slides behave similarly to snow avalanches, the term landslide refers to a variety of mass wasting events that include slumps, slides, falls, and flows. The two major types of slides are slides and translational slides. Rockslides are a type of translational event since the rock mass moves along a planar surface with little rotation or backward tilting. Rock slides are the most dangerous form of mass-wasting due to the fact that they incorporate a sudden, Rock may break down while falling during rockslides. Mass-wasting occurs whenever gravitational pressure exceeds the affected slopes ability to resist its pressure, therefore, anything that erodes or impedes the mountains ability to resist this force may be one of the causes of mass-wasting. While a major event such as an earthquake can cause large rockslides to happen, amongst these erosional properties, water is arguably the most effective geologic agent that causes mass-wasting events to occur. While these processes can cause a slide to happen, the speed, with increasing populations in rural areas around the world, the hazards presented by potential rock slides are becoming more of a pressing issue moving forward. Luckily, individuals working in the fields of science and engineering continue to perfect methods of rock slide detection, assessment. New earth observation tools have supplied a much enhanced ability to detect potential rock slide hazards, analysis of sequential InSAR and LiDAR data provides a very valuable regional view of slope movement. Once susceptible areas are discovered, detailed analysis can be carried out at the specific sight and these assessments are used to determine the amount of material that will be released as well as the speed at which this material will be transported. Once a site is deemed hazardous, different types of geologic engineering techniques are used in order to prevent the compromised slope from failing, some of these designs are listed below. Wire Meshing A corrosion resistant material that is installed at the crest and this insures that any falling debris is trapped behind the mesh. Soil Nailing An economical method of constructing a form of retaining wall from the top of a slope down, in this process closely spaced steel tendons are drilled into the soil. These nails significantly increase the cohesion of soil through the ability of these rods to carry tensile loads and these steel beams are usually reinforced through the use of welded wire mesh. Rock Bolting Rock bolts are always a means of reinforcement, Bolts are placed in a specific pattern in order to transfer the faces load from the slopes exterior. Sturzstrom, a type of landslide consisting of soil and rock
9.
Mudflow
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Mudflows contain a significant proportion of clay, which makes them more fluid than debris flows, thus, they are able to travel farther and across lower slope angles. Both types are generally mixtures of various kinds of materials of different sizes, mudflows are often called mudslides, a term applied indiscriminately by the mass media to a variety of mass wasting events. Mudflows often start as slides, becoming flows as water is entrained along the flow path, other types of mudflows include lahars and jökulhlaups. A statutory definition of flood-related mudslide appears in the United States National Flood Insurance Act of 1968, as amended, codified at 42 USC Sections 4001, heavy rainfall, snowmelt, or high levels of ground water flowing through cracked bedrock may trigger a movement of soil or sediments. Floods and debris flows may also occur when strong rains on hill or mountain slopes cause extensive erosion and/or what is known as channel scour, the 2006 Sidoarjo mud flow may have been caused by rogue drilling. Some broad mudflows are rather viscous and therefore slow, others very quickly. If large enough, they can devastate villages and countrysides and they are composed of at least 50% silt and clay-sized materials and up to 30% water. The point where a material begins to flow depends on its grain size. Fine grainy material or soil has a friction angle than a coarse sediment or a debris flow. On December 14,1999 in Vargas, Venezuela, a known as The Vargas tragedy significantly altered more than 60 kilometers of the coastline. Landslide is a general term than mudflow. It refers to the failure and subsequent movement downslope of any types of surface movement of soil, rock. The term incorporates earth slides, rock falls, debris flows and they do not have to be as fluid as a mudflow. Mudflows can be caused by heavy rains or a sudden thaw. They consist mainly of mud and water plus fragments of rock and other debris and they can move houses off their foundations or bury a place within minutes because of incredibly strong currents. When a mudflow occurs it is given four named areas, the scarp, in bigger mudflows the upper and lower shelves. The main scarp will be the area of incidence, the toe is the last affected area. The upper and lower shelves are located there is a large dip in the mudflows path
10.
Landslide
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A landslide, also known as a landslip, is a form of mass wasting that includes a wide range of ground movements, such as rockfalls, deep failure of slopes, and shallow debris flows. Landslides can occur underwater, called a submarine landslide, coastal, although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the prone to failure. Landslides occur when the changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, slope material that becomes saturated with water may develop into a debris flow or mud flow. The resulting slurry of rock and mud may pick up trees, houses and cars, debris flow is often mistaken for flash flood, but they are entirely different processes. Muddy-debris flows in alpine areas cause severe damage to structures and infrastructure, muddy-debris flows can start as a result of slope-related factors and shallow landslides can dam stream beds, resulting in temporary water blockage. As the impoundments fail, an effect may be created, with a remarkable growth in the volume of the flowing mass. The solid–liquid mixture can reach densities of up to 2,000 kg/m3, for a small basin in the Italian Alps affected by a debris flow, estimated a peak discharge of 750 m3/s for a section located in the middle stretch of the main channel. At the same section, the maximum foreseeable water discharge, was 19 m3/s. Earthflows are downslope, viscous flows of saturated, fine-grained materials, typically, they can move at speeds from 0.17 to 20 km/h. Though these are a lot like mudflows, overall they are slow moving and are covered with solid material carried along by flow from within. They are different from fluid flows which are more rapid, clay, fine sand and silt, and fine-grained, pyroclastic material are all susceptible to earthflows. The velocity of the earthflow is all dependent on how much content is in the flow itself, if there is more water content in the flow. This thereby creates a bulging lobe which advances with a slow, as these lobes spread out, drainage of the mass increases and the margins dry out, thereby lowering the overall velocity of the flow. This process causes the flow to thicken, the bulbous variety of earthflows are not that spectacular, but they are much more common than their rapid counterparts. They develop a sag at their heads and are derived from the slumping at the source. Earthflows occur much more during periods of precipitation, which saturates the ground
11.
Serac
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A serac is a block or column of glacial ice, often formed by intersecting crevasses on a glacier. Commonly house-sized or larger, they are dangerous to mountaineers since they may topple with little warning, even when stabilized by persistent cold weather, they can be an impediment to glacier travel. Seracs are found within an icefall, often in large numbers, notable examples of this type are well-known obstacles on some of the worlds highest mountains, including K2 at The Bottleneck or Kanchenjunga on the border of India and Nepal. Significant seracs in the Alps are found on the northeast face of Piz Roseg, the face of the Dent dHérens. The collapse of large seracs was responsible for at least 8 of the 11 deaths of the August 2008 climbing accident on K2, in April 2014, a large serac broke off and caused an avalanche on Mount Everest, which was responsible for the deaths of 16 climbers. On a 1970 Japanese expedition to Mount Everest Kyak Tsering was killed by a falling serac
12.
Icefall
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An icefall is a portion of certain glaciers characterized by rapid flow and a chaotic crevassed surface. The term icefall is formed by analogy with the waterfall, a similar. When ice movement is faster than elsewhere, because the glacier bed steepens or narrows, the flow cannot be accommodated by plastic deformation, where two fractures meet, seracs can be formed. When the movement of the ice slows down, the crevasses can coalesce, perhaps the most conspicuous consequence of glacier flow, icefalls occur where the glacier bed steepens and/or narrows. Most glacier ice flows at speeds of a few hundred metres per year or less, however, the flow of ice in an icefall may be measured in kilometres per year. Such rapid flow cannot be accommodated by deformation of the ice. Instead, the ice fractures forming crevasses, intersecting fractures form ice columns or seracs. These processes are imperceptible for the most part, however, a serac may collapse or topple abruptly and this behavior often poses the biggest risk to mountaineers climbing in an icefall. Below the icefall, the bed flattens and/or widens and the ice flow slows. Crevasses close and the surface becomes much smoother and easier to traverse. The Roosevelt Glacier icefall, on the face of Mount Baker, is about 730 metres high. The ice cliff of the side of the ice fall. Typical of mountain glaciers, this icefall forms as the ice flows from a high plateau or basin accumulation zone to a lower valley ablation zone. Much larger icefalls may be found in the glaciers of continental ice sheets. Icefalls are climbed because of their beauty and the challenge they pose, in some cases, an icefall may provide the only feasible or the easiest route up one face of a mountain. An example is the Khumbu Icefall on the Nepalese side of Mount Everest and it is about 5,500 metres above sea level. Glacier morphology Media related to Icefalls at Wikimedia Commons
13.
Natural hazard
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A natural hazard is a natural phenomenon that might have a negative effect on people or the environment. Natural hazard events can be grouped into two broad categories, geophysical hazards encompass geological and meteorological phenomena such as earthquakes, volcanic eruption, wildfire, cyclonic storms, flood, drought, and coastal erosion. Biological hazards can refer to an array of disease and infestation. Many geophysical hazards are related, for example, submarine earthquakes can cause tsunamis, floods and wildfires can result from a combination of geological, hydrological, and climatic factors. It is possible that some natural hazards are intertemporally correlated as well, an example of the division between a natural hazard and a natural disaster is that the 1906 San Francisco earthquake was a disaster, whereas living on a fault line is a hazard. An avalanche occurs when a large snow mass slides down a mountainside, an avalanche is an example of a gravity current consisting of granular material. In an avalanche, lots of material or mixtures of different types of fall or slide rapidly under the force of gravity. Avalanches are often classified by the size or severity of consequences resulting from the event, an earthquake is the sudden release of energy stored as lithospheric stress that radiates seismic waves. Many earthquakes happen each day, few of which are enough to cause significant damage. Coastal erosion can result from long-term processes as well as from events such as tropical cyclones or other severe storm events. These flows can destroy entire towns in seconds and kill thousands of people and this is based on natural events. A landslide is a displacement of sediment, usually down a slope. A sinkhole is a depression in the surface topography, usually caused by the collapse of a subterranean structure such as a cave. Although rare, large sinkholes that develop suddenly in populated areas can lead to the collapse of buildings, a volcanic eruption is the point in which a volcano is active and releases its power, and the eruptions come in many forms. They range from daily small eruptions occur in places like Kilauea in Hawaii, to megacolossal eruptions from supervolcanoes like Lake Taupo. Some eruptions form pyroclastic flows, which are high-temperature clouds of ash, a blizzard is a severe winter stormer icy and windy conditions characterized by low temperature, strong wind and heavy snow. Scientists warn that global warming and climate change may result in more extensive droughts in coming years and these extensive droughts are likely to occur within the African continent due to its very low precipitation levels and high climate. A hailstorm is a hazard where a thunderstorm produces numerous hailstones which damage the location in which they fall
14.
North Cascades
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The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U. S. state of Washington and are named in the U. S. They are predominantly non-volcanic, but include the stratovolcanoes Mount Baker, Glacier Peak and Coquihalla Mountain, while most of the peaks are under 10,000 feet in elevation, the low valleys provide great local relief, often over 6,000 feet. Portions of the US side of the range are protected as part of North Cascades National Park. The large amount of precipitation, much of it in the form of snow, deep, U-shaped valleys carved by glaciers in Pleistocene time separate sharp ridges and peaks carved into steep shapes by more recent snow and ice. The Fraser River and the lowland on its south bank form the northern and northwestern boundary of the range. On the west, the foothills of the range are separated by a coastal plain from Puget Sound except along Chuckanut Drive between Bellingham and Mount Vernon, where they abut the Sound directly. The southern boundary of the North Cascades is less definite, for the purposes of this article, it will be taken as U. S. Highway 2, running over Stevens Pass, or equivalently, the Skykomish River, Nason Creek, and the lower Wenatchee River. This roughly follows Beckeys geologic division in Cascade Alpine Guide. sometimes the southern boundary is defined by Snoqualmie Pass and the approximate route of Interstate 90. Sometimes the term North Cascades or northern Cascades is used for the range north of the Columbia River. Geologically, the rocks of the North Cascades extend south beyond Stevens Pass, the significance of the geologic transitions to the Okanagan Highland to the east and the Interior Plateau and Coast Mountains to the north are less agreed upon. The climate in the North Cascades varies considerably by location and elevation, the western slope of the range is wet and cool, with 60 to 250 inches of precipitation per year. This produces a rain forest climate in the low valleys. Sometimes, the storms move downwind into lowland cities, as with most mountainous areas, precipitation increases dramatically with increasing elevation. As a result, there is a deal of winter snow. The eastern slopes and mountain passes can receive significant snowfall, cold Arctic air can flow south from British Columbia through the Okanogan River valley into the bowl-like basin east of the Cascades. Cold air damming causes this Arctic air to bank up along the eastern Cascade slopes, especially into the lower passes, such as Snoqualmie Pass and Stevens Pass. The milder, Pacific-influenced air moving east over the Cascades is often forced aloft by the air held in place in the passes due to cold air damming
15.
Mount Shuksan
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Mount Shuksan is a glaciated massif in the North Cascades National Park. Shuksan rises in Whatcom County, Washington immediately to the east of Mount Baker, the mountains name Shuksan is derived from the Lummi word, said to mean high peak. The highest point on the mountain is a three sided peak known as Summit Pyramid, the mountain is composed of Shuksan greenschist, oceanic basalt that was metamorphosed when the Easton terrane collided with the west coast of North America, approximately 120 million years ago. The mountain is a remnant of a thrust plate formed by the Easton collision. Mount Shuksan may be one of the most photographed mountains in the Cascade Range, photographs with its reflection in Picture Lake near Mount Baker Ski Area are particularly common. Sulphide Creek Falls, one of the tallest waterfalls in North America, there are four other tall waterfalls that spill off Mount Shuksan and neighboring Jagged Ridge and Seahpo Peak, mostly sourced from small snowfields and glaciers. The traditional name of Mount Shuksan in the Nooksack language is Shéqsan or Ch’ésqen, the first ascent of Mount Shuksan is usually attributed to Asahel Curtis and W. Montelius Price on September 7,1906. Mount Triumph Mount Despair Mount Terror Mount Blum Mount Baker Church Mountain Mount Shuksan, Mount Shucksan Views from Table Mountain Hike
16.
Mount Baker
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Mount Baker, also known as Koma Kulshan or simply Kulshan, is an active glaciated andesitic stratovolcano in the Cascade Volcanic Arc and the North Cascades of Washington in the United States. Mount Baker has the second-most thermally active crater in the Cascade Range after Mount Saint Helens, about 31 miles due east of the city of Bellingham, Whatcom County, Mount Baker is the youngest volcano in the Mount Baker volcanic field. While volcanism has persisted here for some 1.5 million years, the current glaciated cone is likely no more than 140,000 years old, older volcanic edifices have mostly eroded away due to glaciation. It is also one of the snowiest places in the world, in 1999, Mount Baker Ski Area, located 14 km to the northeast, set the world record for recorded snowfall in a single season—1,140 in. Located in the Mount Baker Wilderness, it is visible much of Greater Victoria, Nanaimo. The explorer George Vancouver renamed the mountain for 3rd Lieutenant Joseph Baker of HMS Discovery, Mount Baker was well-known to indigenous peoples of the Pacific Northwest. Indigenous names for the mountain include Koma Kulshan or Kulshan, Quck Sam-ik, Kobah (Skagit, qwúbə’, white sentinel, and Tukullum or Nahcullum. In 1790, Manuel Quimper of the Spanish Navy set sail from Nootka, accompanying Quimper was first-pilot Gonzalo Lopez de Haro, who drew detailed charts during the six-week expedition. Although Quimpers journal of the voyage does not refer to the mountain, the Spanish named the snowy volcano La Gran Montana del Carmelo, as it reminded them of the white-clad monks of the Carmelite Monastery. The British explorer George Vancouver left England a year later and his mission was to survey the northwest coast of America. Vancouver and his crew reached the Pacific Northwest coast in 1792, apparently at a very remote distance. Six years later, the narrative of this voyage was published. By the mid-1850s, Mount Baker was a feature on the horizon to the explorers. Stevens, the first governor of Washington Territory, wrote about Mount Baker in 1853, Mount Baker. Is one of the loftiest and most conspicuous peaks of the northern Cascade range, it is nearly as high as Mount Rainier and it is visible from all the water and islands. And from the southeastern part of the Gulf of Georgia. It is for this region a natural and important landmark, edmund Thomas Coleman, an Englishman who resided in Victoria, British Columbia, Canada and a veteran of the Alps, made the first attempt to ascend the mountain in 1866. He chose a route via the Skagit River, but was forced to back when local Native Americans refused him passage
17.
Powder snow avalanche
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A powder snow avalanche is a type of avalanche where the snow grains are largely or wholly suspended by fluid turbulence. They are particle-laden gravity currents and closely related to turbidity currents, pyroclastic flows from volcanoes, the ambient fluid is generally of similar composition to the interstitial fluid, and is water for turbidity currents and air for avalanches. These flows are non-conservative in that they may exchange particles at the boundary by deposition or suspension. Such flows dissipate when the turbulence can no longer hold the particles in suspension, when the turbulence is strong enough to suspend new material from the bed or the underlying dense flow then current is said to be auto-suspending. Particle concentrations in the cloud are usually sufficiently low that particle-particle interactions play a small or negligible role in maintaining the suspension. This is in contrast to turbidity currents and laboratory experiments in water where the inertia of the particles can usually be neglected
18.
Mass wasting
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Types of mass wasting include creep, slides, flows, topples, and falls, each with its own characteristic features, and taking place over timescales from seconds to years. Mass wasting occurs on both terrestrial and submarine slopes, and has observed on Earth, Mars, Venus. When the gravitational force acting on a slope exceeds its resisting force, the slope materials strength and cohesion and the amount of internal friction between material help maintain the slopes stability and are known collectively as the slopes shear strength. The steepest angle that a slope can maintain without losing its stability is known as its angle of repose. When a slope made of loose material possesses this angle, its shear strength perfectly counterbalances the force of gravity acting upon it. Mass wasting may occur at a slow rate, particularly in areas that are very dry or those areas that receive sufficient rainfall such that vegetation has stabilized the surface. It may also occur at high speed, such as in rockslides or landslides, with disastrous consequences. Factors that change the potential of mass wasting include, change in angle, weakening of material by weathering, increased water content, changes in vegetation cover. Volcano flanks can become over-steep resulting in instability and mass wasting and this is now a recognised part of the growth of all active volcanoes. The failure of the flank of Mount St Helens in 1980 showed how rapidly volcanic flanks can deform. Water can increase or decrease the stability of a slope depending on the amount present, small amounts of water can strengthen soils because the surface tension of water increases soil cohesion. This allows the soil to resist erosion better than if it were dry, if too much water is present the water may act to increase the pore pressure, reducing friction, and accelerating the erosion process and resulting in different types of mass wasting. A good example of this is to think of a sand castle, water must be mixed with sand in order for the castle to keep its shape. If too much water is added the sand away, if not enough water is added the sand falls. Water also increases the mass of the soil, this is important because an increase in mass means that there will be an increase in velocity if mass wasting is triggered. Types of mass movement are distinguished based on how the soil, soil creep is a long term process. The combination of movements of soil or rock in different directions over time are directed by gravity gradually downslope. The steeper the slope, the faster the creep, the creep makes trees and shrubs curve to maintain their perpendicularity, and they can trigger landslides if they lose their root footing
19.
Ridge
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A ridge or mountain ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size, there are several main types of ridges, Dendritic ridge, In typical dissected plateau terrain, the stream drainage valleys will leave intervening ridges. These are by far the most common ridges and these ridges usually represent slightly more erosion resistant rock, but not always – they often remain because there were more joints where the valleys formed, or other chance occurrences. This type of ridge is somewhat random in orientation, often changing direction frequently. Similar ridges have formed in such as the Black Hills. Sometimes these ridges are called hogback ridges, oceanic spreading ridge, In tectonic spreading zones around the world, such as at the Mid-Atlantic Ridge, the volcanic activity forming new plate boundary forms volcanic ridges at the spreading zone. Isostatic settling and erosion gradually reduce the moving away from the zone. Crater ridges, Large meteorite strikes typically form large impact craters bordered by circular ridges, volcanic crater/caldera ridges, Large volcanoes often leave behind a central crater/caldera bordered by circular ridges. Fault ridges, Faults often form escarpments, sometimes the tops of the escarpments form not plateaus, but slope back so that the edges of the escarpments form ridges. Dune ridges, In areas of large-scale dune activity, certain types of dunes result in sand ridges, moraines and eskers, Glacial activity may leave ridges in the form of moraines and eskers. An arête is a ridge of rock that is formed by glacial erosion. Volcanic subglacial ridges, Many subglacial volcanoes create ridge-like formations when lava erupts through a glacier or ice sheet. Shutter ridges, A shutter ridge is a ridge which has moved along a fault line, typically, a shutter ridge creates a valley corresponding to the alignment of the fault that produces it
20.
Angle of repose
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The angle of repose, or critical angle of repose, of a granular material is the steepest angle of descent or dip relative to the horizontal plane to which a material can be piled without slumping. At this angle, the material on the face is on the verge of sliding. The angle of repose can range from 0° to 90°, the morphology of the material affects the angle of repose, smooth, rounded sand grains cannot be piled as steeply as can rough, interlocking sands. When bulk granular materials are poured onto a surface, a conical pile will form. Material with a low angle of repose forms flatter piles than material with an angle of repose. The term has a usage in mechanics, where it refers to the maximum angle at which an object can rest on an inclined plane without sliding down. This angle is equal to the arctangent of the coefficient of static friction μs between the surfaces, the angle of repose is sometimes used in the design of equipment for the processing of particulate solids. For example, it may be used to design an appropriate hopper or silo to store the material and this angle of repose is also crucial in correctly calculating stability in vessels. It is also used by mountaineers as a factor in analysing avalanche danger in mountainous areas. There are numerous methods for measuring angle of repose and each produces slightly different results, results are also sensitive to the exact methodology of the experimenter. As a result, data from different labs are not always comparable, one method is the triaxial shear test, another is the direct shear test. If the coefficient of friction is known of a material. This function is somewhat accurate for piles where individual objects in the pile are minuscule, tan ≈ μ s where, μs is the coefficient of static friction, and θ is the angle of repose. They achieve this by flinging the loose sand out of the pit, the larva assists this process by vigorously flicking sand out from the center of the pit when it detects a disturbance. This undermines the pit walls and causes them to collapse toward the center, the combined effect is to bring the prey down to within grasp of the larva, which then can inject venom and digestive fluids. The measured angle of repose may vary with the method used and this method is appropriate for fine-grained, non-cohesive materials, with individual particle size less than 10 mm. The material is placed within a box with a transparent side to observe the granular test material and it should initially be level and parallel to the base of the box. The box is slowly tilted until the material begins to slide in bulk, the material is poured through a funnel to form a cone
21.
Cordillera Paine
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The Cordillera Paine is a small mountain group in Torres del Paine National Park in Chilean Patagonia. It is located 280 km north of Punta Arenas, and about 1,960 km south of the Chilean capital Santiago and it belongs to the Commune of Torres del Paine in Última Esperanza Province of Magallanes and Antártica Chilena Region. No accurate surveys have been published, and published elevations have been claimed to be seriously inflated, Paine means blue in the native Tehuelche language and is pronounced PIE-nay. The highest summit of the range is Cerro Paine Grande, at 50°59′56″S 73°05′43″W. For a long time its elevation was claimed to be 3,050 m or 3,251 m, the best-known and most spectacular summits are the three Towers of Paine. The South Tower of Paine is now thought to be the highest of the three, although this has not been definitely established and it was first climbed by Armando Aste. The Central Tower of Paine was first climbed in 1963 by Chris Bonington and Don Whillans, other summits include the Cuerno Principal, about 2,100 m, and Cerro Paine Chico, which is usually correctly quoted at about 2,650 m. The range is made up of a yellowish granite underlain by grey gabbro-diorite laccolith, the radiometric age for the quartz diorite at Cerro Paine is 12 ±2 million years by the rubidium-strontium method and 13 ±1 million years by the potassium-argon method. Basal gabbro and diorite were dated by a technique to 12.472 ±0.009 to 12.431 ±0.006 million years. Thus, magma was intruded and crystallized over 162 ±11 thousand years, high resolution dating and excellent 3-D exposure of the laccolith and its vertical feeding system allow detailed reconstruction of the Torres del Paine fossil magma chamber history. The Torres del Paine National Park—an area of 2,400 km²—was declared a Biosphere Reserve by the UNESCO in 1978 and is a hiking destination. There are clearly marked and well maintained paths and many refugios which provide shelter, hikers can opt for a day trip to see the towers, walk the popular W route in about five days, or trek the full circle in 8–9 days. The W route is by far the most popular, and is named for the shape of the route, hikers start and finish at either of the base points of the W, performing each of the three shoots as a day trip. The five points of the W, from west to east, are, Glacier Grey, camping is available next to Refugio Grey. Refugio Paine Grande, situated on Lago Pehoé and this site offers good views of the horns of Torres del Paine. Valle del Francés, often rated as the best scenery in the whole park, the path leads up into a snowy dead-end, where several small glaciers are visible. Hotel Las Torres, a hotel at the base of the mountain range. The Torres del Paine themselves, large formations over a small lake
22.
Patagonia
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Patagonia is a sparsely populated region located at the southern end of South America, shared by Argentina and Chile. The region comprises the section of the Andes mountains as well as the deserts, steppes. Patagonia has two coasts, a western one towards the Pacific Ocean and an eastern one towards the Atlantic Ocean, the Colorado and Barrancas rivers, which run from the Andes to the Atlantic, are commonly considered the northern limit of Argentine Patagonia. The archipelago of Tierra del Fuego is sometimes included as part of Patagonia, most geographers and historians locate the northern limit of Chilean Patagonia at Reloncaví Estuary. The name Patagonia comes from the word used by Magellan in 1520 to describe the native people that his expedition thought to be giants. It is now believed that the people he called the Patagons were Tehuelches, the hypothesis was accepted and published in the New Review of Spanish Philology in the 2011 article. In the hollows of the plains are ponds or lakes of fresh and brackish water, towards the Andes, the shingle gives place to porphyry, granite, and basalt lavas, animal life becomes more abundant and vegetation more luxuriant. It is characteristic of the flora of the western coast, and consist principally of southern beech and conifers. Among the depressions by which the plateau is intersected transversely, the ones are the Gualichu, south of the Río Negro, the Maquinchao and Valcheta, the Senguerr. There, erosion which is caused principally by the sudden melting, best in evidence where in contact with folded Cretaceous rocks which are uplifted by the Cenozoic granite. It generally separates the plateau from the first lofty hills, the ridges generally called the pre-Cordillera, to the west of these, a similar longitudinal depression extends all along the foot of the snowy Andean Cordillera. This latter depression contains the richest and most fertile land of Patagonia, Lake basins along the Cordillera were also excavated by ice-streams, including Lake Argentino and Lake Fagnano, as well as coastal bays such as Bahía Inútil. There have been discrepancies among geologists on the origin of the Patagonian landmass, víctor Ramos has proposed that the Patagonian landmass originated as an allochtonous terrane that separated from Antarctica and docked in South America 250 to 270 Ma in the Permian era. A2014 study by Robert John Pankhurst and coworkers reject any idea of a far-travelled Patagonia claiming it is likely of parautochtonous origin, the Mesozoic and Cenozoic deposits have revealed a most interesting vertebrate fauna. The Patagonian Myolania belongs to the Upper Chalk, having been associated with remains of Dinosauria. In the Cenozoic marine formation, a number of cetaceans has been discovered. At a state level, Patagonia lies inside two countries, Chile and Argentina, both countries have organised their Patagonian territories into non-equivalent administrative subdivisions, Provinces and departments in Argentina, and regions, provinces and communes in Chile. Being a unitary state Chiles first level administrative divisions—the regions—enjoy far less autonomy than Argentine provinces, Argentine provinces have elected governors and parliaments, while Chilean regions have government-appointed intendants
23.
Glacier Peak Wilderness
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Glacier Peak Wilderness is a 566, 057-acre, 35-mile-long, 20-mile-wide wilderness area located within portions of Chelan, Snohomish, and Skagit counties in the North Cascades of Washington. The dominant geologic feature of the area is 10, 541-foot Glacier Peak and it is the most remote major volcanic peak in the Cascade Range and has more active glaciers than any other place in the lower forty-eight states. Glacier Peak is a cone of basalt, pumice. Forest vegetation comprises several species of fir, Douglas fir, hemlock, red cedar as well as stands of mixed pine, various species of wildlife inhabit the area and include deer, elk, black bear, mountain goat, cougar, marten, and lynx. Smaller animals, such as mice are common. The last confirmed grizzly bear sighting in the United States portion of the North Cascade ecosystem occurred in this wilderness, the high mountain lakes often give good catches of fish during their ice-free months. The primary fishery is cutthroat trout, however, other species do exist, no roads approach Glacier Peak, and many miles of hiking through extremely rough terrain to reach its base. Most years the wilderness is still buried under 10 to 20 feet of snow in May, usually most trails and passes are snow free by mid-August, but this varies from year to year. Snow and cold rain can occur in mid-summer, on October 20,2003, there was a record-setting flood event when over 10 inches of rain fell on the wilderness. The warm rain melted snow and ice driving massive amounts of water, trees, downstream, roads, bridges, campgrounds and trails were damaged and destroyed. The destruction was devastating to the Pacific Crest Trail. Eight trail bridges and one stream ford on a 30-mile section of the trail below Glacier Peak were destroyed, little or no evidence remains that some of these bridges ever existed. The two most notable losses were bridges over the Upper White Chuck River and the Suiattle River, both crossings are dangerous fords under the best of conditions. Additionally, five trails that provided access to the PCT in the area sustained varying degrees of damage from fairly light to severe. Kennedy Hot Springs was buried in a mudslide and completely destroyed, construction on the Suiattle River road began in 2013 and was scheduled to be completed by October 2014. Dome Peak Image Lake Ptarmigan Traverse This article incorporates public domain material from websites or documents of the U. S. Forest Service, Glacier Peak Wilderness U. S. Forest Service Glacier Peak Wilderness U. S. Forest Service Glacier Peak Wilderness Wilderness. net
24.
Washington (state)
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It was admitted to the Union as the 42nd state in 1889. Washington is sometimes referred to as Washington State or the State of Washington to distinguish it from Washington, Washington is the 18th largest state with an area of 71,362 square miles, and the 13th most populous state with over 7 million people. Washington is the second most populous state on the West Coast and in the Western United States, Mount Rainier, an active stratovolcano, is the states highest elevation at almost 14,411 feet and is the most topographically prominent mountain in the contiguous United States. Washington is a leading lumber producer and its rugged surface is rich in stands of Douglas fir, hemlock, ponderosa pine, white pine, spruce, larch, and cedar. Manufacturing industries in Washington include aircraft and missiles, shipbuilding and other equipment, lumber, food processing, metals and metal products, chemicals. Washington has over 1,000 dams, including the Grand Coulee Dam, built for a variety of purposes including irrigation, power, flood control, the Washington Territory was named after George Washington, the first President of the United States. The area was part of a region called the Columbia District after the Columbia River. The area was renamed Washington in order to avoid confusion with the District of Columbia, Washington is the only U. S. state named after a president. To distinguish it from the U. S. capital, which is named for George Washington, Washington is sometimes referred to as Washington State, or, in more formal contexts. Washingtonians and other residents of the Pacific Northwest refer to the state simply as Washington, calling the nations capital Washington, D. C. or, often, Washington is the northwestern-most state of the contiguous United States. Washington is bordered by Oregon to the south, with the Columbia River forming the western part, to the west of Washington lies the Pacific Ocean. The high mountains of the Cascade Range run north-south, bisecting the state, from the Cascade Mountains westward, Western Washington has a mostly marine west coast climate, with mild temperatures and wet winters, autumns and springs, and relatively dry summers. The Cascade Range contains several volcanoes, which reach altitudes significantly higher than the rest of the mountains, from the north to the south, these major volcanoes are Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams. Mount Rainier, the tallest mountain in the state, is 50 miles south of the city of Seattle and it is also covered with more glacial ice than any other peak in the contiguous 48 states. Western Washington also is home of the Olympic Mountains, far west on the Olympic Peninsula and these deep forests, such as the Hoh Rainforest, are among the only temperate rainforests in the continental United States. Eastern Washington – the part of the state east of the Cascades – has a dry climate. It includes large areas of steppe and a few truly arid deserts lying in the rain shadow of the Cascades. Farther east, the climate becomes less arid, with annual rainfall increasing as one goes east to 21.2 inches in Pullman, the Okanogan Highlands and the rugged Kettle River Range and Selkirk Mountains cover much of the northeastern quadrant of the state
25.
Snow cornice
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A snow cornice or simply cornice is an overhanging edge of snow on a ridge or the crest of a mountain and along the sides of gullies. They form by wind blowing snow over sharp terrain breaks where it attaches and this build-up is most common on the leeward sides of mountains. Cornices are extremely dangerous and travelling above or below them should be avoided, when a cornice collapses, it breaks in from the cornice to the top of the peak, even being on the snow on top of rock exposes the alpinist to hazard in this situation. The best practice in mountaineering is to stay far enough back from the edge so as not to be able to see the drop, of course, this is not always possible. A good test for safety is to insert an ice axe and this indicates the ice is being lit from underneath, and that the climber should retreat to a safer location. In avalanche safety, cornices are a high avalanche danger as they often break, cornices are particularly vulnerable to collapse during periods of solar warming. List of climbing topics Sastrugi Media related to Snow cornices at Wikimedia Commons Cornice from the Avalanche Encyclopedia Climber found dead in Mount St. Helens crater after falling through cornice
26.
Sunlight
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Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is filtered through Earths atmosphere, and is obvious as daylight when the Sun is above the horizon, when the direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When it is blocked by clouds or reflects off other objects, the World Meteorological Organization uses the term sunshine duration to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per square meter. Other sources indicate an Average over the earth of 164 Watts per square meter over a 24 hour day. The ultraviolet radiation in sunlight has both positive and negative effects, as it is both a principal source of vitamin D3 and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface. Researchers may record sunlight using a sunshine recorder, pyranometer, or pyrheliometer, to calculate the amount of sunlight reaching the ground, both Earths elliptical orbit and the attenuation by Earths atmosphere have to be taken into account. In this formula dn–3 is used, because in modern times Earths perihelion, the closest approach to the Sun and, therefore, the value of 0.033412 is determined knowing that the ratio between the perihelion squared and the aphelion squared should be approximately 0.935338. The solar illuminance constant, is equal to 128×103 lx, the atmospheric extinction brings the number of lux down to around 100000. The total amount of energy received at ground level from the Sun at the zenith depends on the distance to the Sun and it is about 3. 3% higher than average in January and 3. 3% lower in July. In terms of energy, sunlight at Earths surface is around 52 to 55 percent infrared,42 to 43 percent visible, and 3 to 5 percent ultraviolet. At the top of the atmosphere, sunlight is about 30% more intense, having about 8% ultraviolet, direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux. This is higher than the efficacy of most artificial lighting, which means using sunlight for illumination heats up a less than using most forms of artificial lighting. Multiplying the figure of 1050 watts per square metre by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98000 lux on a surface at sea level. The illumination of a surface will be considerably less than this if the Sun is not very high in the sky. Averaged over a day, the highest amount of sunlight on a horizontal surface occurs in January at the South Pole, dividing the irradiance of 1050 W/m2 by the size of the suns disk in steradians gives an average radiance of 15.4 MW per square metre per steradian. Multiplying this by π gives a limit to the irradiance which can be focused on a surface using mirrors,48.5 MW/m2
27.
Convex function
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Equivalently, a function is convex if its epigraph is a convex set. Also equivalently, if the function is differentiable, and the second derivative is always greater than or equal to zero for its entire domain. Well-known examples of convex functions include the function x 2. Convex functions play an important role in areas of mathematics. They are especially important in the study of problems where they are distinguished by a number of convenient properties. For instance, a function on an open set has no more than one minimum. In probability theory, a convex function applied to the value of a random variable is always less than or equal to the expected value of the convex function of the random variable. This result, known as Jensens inequality, underlies many important inequalities, let X be a convex set in a real vector space and let f, X → R be a function. F is called if, ∀ x 1, x 2 ∈ X, ∀ t ∈, f ≤ t f + f. F is called convex if, ∀ x 1 ≠ x 2 ∈ X, ∀ t ∈, f < t f + f. A function f is said to be concave if −f is convex, suppose f is a function of one real variable defined on an interval, and let R = f − f x 1 − x 2. F is convex if and only if R is monotonically non-decreasing in x1 and this characterization of convexity is quite useful to prove the following results. A convex function f defined on some open interval C is continuous on C, F admits left and right derivatives, and these are monotonically non-decreasing. As a consequence, f is differentiable at all but at most countably many points, if C is closed, then f may fail to be continuous at the endpoints of C.3. A function is midpoint convex on an interval C if ∀ x 1, x 2 ∈ C, f ≤ f + f 2 and this condition is only slightly weaker than convexity. For example, a real-valued Lebesgue measurable function that is midpoint-convex will be convex by the Sierpinski theorem, in particular, a continuous function that is midpoint convex will be convex. A differentiable function of one variable is convex on an interval if, if a function is differentiable and convex then it is also continuously differentiable. For the basic case of a function from the real numbers to the real numbers
28.
Concave function
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In mathematics, a concave function is the negative of a convex function. A concave function is also synonymously called concave downwards, concave down, convex upwards, a real-valued function f on an interval is said to be concave if, for any x and y in the interval and for any α in, f ≥ f + α f. A function is called strictly concave if f > f + α f for any α in and x ≠ y. For a function f, R→R, this definition merely states that for every z between x and y, the point on the graph of f is above the line joining the points. A function f is quasiconcave if the upper contour sets of the function S = are convex sets, a function f is concave over a convex set if and only if the function −f is a convex function over the set. Points where concavity changes are inflection points, the sum of two concave functions is itself concave and so is the pointwise minimum of two concave functions, i. e. the set of concave functions on a given domain form a semifield. If f is twice-differentiable, then f is concave if and only if f ′′ is non-positive, if its second derivative is negative then it is strictly concave, but the opposite is not true, as shown by f = −x4. Any local maximum of a function is also a global maximum. A strictly concave function will have at most one global maximum, if f is concave and differentiable, then it is bounded above by its first-order Taylor approximation, f ≤ f + f ′. A continuous function on C is concave if and only if for any x and y in C f ≥ f + f 2, if a function f is concave, and f ≥0, then f is subadditive.5 are always negative. The logarithm function f = log x is concave on its domain, any affine function f = a x + b is both concave and convex, but not strictly-concave nor strictly-convex. The sine function is concave on the interval, the function f = log | B |, where | B | is the determinant of a nonnegative-definite matrix B, is concave. Practical example, rays bending in computation of radiowave attenuation in the atmosphere, concave polygon Convex function Jensens inequality Logarithmically concave function Quasiconcave function Crouzeix, J. -P. In Durlauf, Steven N. Blume, Lawrence E, the New Palgrave Dictionary of Economics. Rao, Singiresu S. Engineering Optimization, Theory and Practice
29.
Ultimate tensile strength
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In other words, tensile strength resists tension, whereas compressive strength resists compression. Ultimate tensile strength is measured by the stress that a material can withstand while being stretched or pulled before breaking. In the study of strength of materials, tensile strength, compressive strength, some materials break very sharply, without plastic deformation, in what is called a brittle failure. Others, which are more ductile, including most metals, experience some plastic deformation, the UTS is usually found by performing a tensile test and recording the engineering stress versus strain. The highest point of the curve is the UTS. It is a property, therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, Tensile strengths are rarely used in the design of ductile members, but they are important in brittle members. They are tabulated for common materials such as alloys, composite materials, ceramics, plastics, Tensile strength can be defined for liquids as well as solids under certain conditions. Tensile strength is defined as a stress, which is measured as force per unit area, for some non-homogeneous materials it can be reported just as a force or as a force per unit width. In the International System of Units, the unit is the pascal, or, equivalently to pascals, Many materials can display linear elastic behavior, defined by a linear stress–strain relationship, as shown in the left figure up to point 3. Beyond this elastic region, for materials, such as steel. A plastically deformed specimen does not completely return to its original size, for many applications, plastic deformation is unacceptable, and is used as the design limitation. The reversal point is the stress on the engineering stress–strain curve. The UTS is not used in the design of static members because design practices dictate the use of the yield stress. It is, however, used for quality control, because of the ease of testing and it is also used to roughly determine material types for unknown samples. The UTS is a common engineering parameter to design members made of material because such materials have no yield point. Typically, the testing involves taking a sample with a fixed cross-sectional area. When testing some metals, indentation hardness correlates linearly with tensile strength and this important relation permits economically important nondestructive testing of bulk metal deliveries with lightweight, even portable equipment, such as hand-held Rockwell hardness testers
30.
Compressive strength
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In other words, compressive strength resists compression, whereas tensile strength resists tension. In the study of strength of materials, tensile strength, compressive strength, some materials fracture at their compressive strength limit, others deform irreversibly, so a given amount of deformation may be considered as the limit for compressive load. Compressive strength is a key value for design of structures, Compressive strength is often measured on a universal testing machine, these range from very small table-top systems to ones with over 53 MN capacity. Measurements of compressive strength are affected by the specific test method, Compressive strengths are usually reported in relationship to a specific technical standard. When a specimen of material is loaded in such a way that it extends it is said to be in tension, on the other hand, if the material compresses and shortens it is said to be in compression. On an atomic level, the molecules or atoms are forced apart when in tension whereas in compression they are forced together. Since atoms in solids always try to find an equilibrium position, the phenomena prevailing on an atomic level are therefore similar. Tension tends to pull small sideways deflections back into alignment, while compression tends to amplify such deflection into buckling, Compressive strength is measured on materials, components, and structures. By definition, the compressive strength of a material is that value of uniaxial compressive stress reached when the material fails completely. The compressive strength is usually obtained experimentally by means of a compressive test, the apparatus used for this experiment is the same as that used in a tensile test. However, rather than applying a uniaxial tensile load, a uniaxial compressive load is applied, as can be imagined, the specimen is shortened as well as spread laterally. In a compression test, there is a region where the material follows Hookes Law. Hence for this region σ = E ϵ where this time E refers to the Youngs Modulus for compression, in this region, the material deforms elastically and returns to its original length when the stress is removed. This linear region terminates at what is known as the yield point, above this point the material behaves plastically and will not return to its original length once the load is removed. There is a difference between the stress and the true stress. By its basic definition the uniaxial stress is given by, σ = F A where, F = Load applied, A = Area As stated, in reality therefore the area is some function of the applied load i. e. Indeed, stress is defined as the force divided by the area at the start of the experiment, in engineering design practice, professionals mostly rely on the engineering stress. In reality, the stress is different from the engineering stress
31.
Tree line
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The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and in frigid environments, beyond the tree line, trees cannot tolerate the environmental conditions. The tree line should not be confused with a lower timberline or forest line, at the tree line, tree growth is often sparse and stunted, with the last trees forming densely matted bushes, known as krummholz. The tree line, like other natural lines, appears well-defined from a distance. Trees grow shorter towards the inhospitable climate until they stop growing. The climate above the line of mountains is called an alpine climate. In the northern hemisphere treelines on north-facing slopes are lower than on south-facing slopes because the increased shade on north-facing slopes means the snowpack takes longer to melt and this shortens the growing season for trees. In the southern hemisphere, the slopes have the shorter growing season. The alpine tree line boundary is seldom abrupt, it forms a transition zone between closed forest below and treeless alpine tundra above. Environmentally dwarfed shrubs commonly forms the upper limit, the decrease in air temperature due to increasing elevation causes the alpine climate. Skin effects and topography can create microclimates that alter the general cooling trend, however, the number of degree days calculated from leaf temperatures may be very similar in the two kinds of timberlines. A series of warm summers in the 1940s seems to have permitted the establishment of “significant numbers” of spruce seedlings above the treeline in the hills near Fairbanks. Survival depends on a sufficiency of new growth to support the tree, the windiness of high-elevation sites is also a potent determinant of the distribution of tree growth. However, snow accumulation in sheltered gullies in the Selkirk Mountains of southeastern British Columbia causes timberline to be 400 metres lower than on exposed intervening shoulders. In a desert, the line marks the driest places where trees can grow. These tend to be called the tree line and occur below about 5,000 ft elevation in the Desert Southwestern United States. In some mountainous areas, higher elevations above the line or on equator-facing and leeward slopes can result in low rainfall. This dries out the soil, resulting in an arid environment unsuitable for trees
32.
Mount Stephen
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Mount Stephen,3,199 m, is a mountain located in the Kicking Horse River Valley of Yoho National Park, ½ km east of Field, British Columbia, Canada. The mountain was named in 1886 for George Stephen, the first president of the Canadian Pacific Railway, the mountain is composed mainly of shales and dolomites from the Cambrian Period, some 550 million years ago. The Stephen Formation, a unit of the Western Canadian Sedimentary Basin was first described at the mountain and was named for it. The first ascent was made in September 1887 by James, J. McArthur and his assistant T. Riley, which was made even more difficult by the surveying equipment they also carried with them. Unfortunately for them, smoke from forest fires limited visibility from the top, the main route ascends slopes on the southwest face but requires much route finding and the final section of 125 m to the top is rated difficult. A cornice on the summit may prevent parties from reaching the top so if in doubt of conditions, the route also passes through a fossil bed and thus requires a special park permit to be in the area. The elevation gain is 1,920 m, for rock climbers, a route on the north ridge is rated III5.7 with generally good rock formations composed mainly of quartzite. Mount Stephen trilobite beds Mount Stephen House
33.
Kicking Horse Pass
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Kicking Horse Pass is a high mountain pass across the Continental Divide of the Americas of the Canadian Rockies on the Alberta/British Columbia border, and lying within Yoho and Banff National Parks. The pass was first explored by Europeans in 1858 by the Palliser Expedition led by Captain John Palliser, due to frequent accidents and expensive helper engines associated with railroading in the pass, the CPR opened a pair of Spiral Tunnels in 1909 that replaced the direct route. Although these tunnels add several kilometres to the route, the grade was reduced to a more manageable 2.2 percent. The Trans-Canada Highway was constructed through the pass in 1962 following essentially the original CPR route and it reaches its highest point at the Kicking Horse Pass with an elevation of 1,643 metres. Divide Creek, a creek that forks onto both sides of the Continental Divide, is located at Kicking Horse Pass, dave Broadfoot played The Honourable Member for Kicking Horse Pass in the CBC Television satirical series Royal Canadian Air Farce and in his personal standup routines. List of Rocky Mountain passes on the continental divide Zoomable map of Kicking Horse Pass showing railway Ten Mile Hill Project HD Video LibriVox Audiobook Recordings
34.
Frost
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Frost is the coating or deposit of ice that may form in humid air in cold conditions, usually overnight. In temperate climates it most commonly appears as white crystals or frozen dew drops near the ground. Frost is composed of delicate branched patterns of ice crystals formed as the result of fractal process development, Frost is known to damage crops or reduce future crop yields, therefore farmers in those regions where frost is a problem often invest substantial means to prevent its formation. In most temperate countries such temperatures usually are the result of loss by radiation at night. The size of frost crystals varies depending on the time they have been building up, Frost crystals may be clear or translucent, but, like snow, a mass of frost crystals will scatter light in all directions, so that a coating of frost appears white. If a solid surface is chilled below the dew point of the humid air. If the water deposits as a liquid that freezes, it forms a coating that may look glassy, opaque, or crystalline. Depending on context, that also may be called atmospheric icing. The ice it produces differs in ways from crystalline frost. For desublimation to proceed the surface must be below the frost point of the air, the air must be humid, but not sufficiently humid to permit the condensation of liquid water, or icing will result instead of desublimation. The size of the crystals depends largely on the temperature, the amount of water vapor available, as a rule, except in conditions where supercooled droplets are present in the air, frost will form only if the deposition surface is colder than the surrounding air. For instance frost may be observed around cracks in cold wooden sidewalks when humid air escapes from the ground beneath. Other objects on which frost commonly forms are those with low specific heat or high thermal emissivity, such as blackened metals, the apparently erratic occurrence of frost in adjacent localities is due partly to differences of elevation, the lower areas becoming colder on calm nights. Where static air settles above an area of ground in the absence of wind, hoar frost refers to white ice crystals, deposited on the ground or loosely attached to exposed objects such as wires or leaves. They form on cold, clear nights when conditions are such that heat radiates out to the sky faster than it can be replaced from nearby sources such as wind or warm objects. Under suitable circumstances, objects cool to below the frost point of the surrounding air, such freezing may be promoted by effects such as flood frost or frost pocket. These occur when ground-level radiation losses cool air till it flows downhill and accumulates in pockets of cold air in valleys. Hoar frost may freeze in such low-lying cold air even when the air temperature a few feet above ground is well above freezing
35.
Friction
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Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction, Dry friction resists relative lateral motion of two surfaces in contact. Dry friction is subdivided into static friction between non-moving surfaces, and kinetic friction between moving surfaces, fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces, skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. Internal friction is the force resisting motion between the making up a solid material while it undergoes deformation. When surfaces in contact move relative to other, the friction between the two surfaces converts kinetic energy into thermal energy. This property can have consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Kinetic energy is converted to thermal energy whenever motion with friction occurs, another important consequence of many types of friction can be wear, which may lead to performance degradation and/or damage to components. Friction is a component of the science of tribology, Friction is not itself a fundamental force. Dry friction arises from a combination of adhesion, surface roughness, surface deformation. The complexity of interactions makes the calculation of friction from first principles impractical and necessitates the use of empirical methods for analysis. Friction is a non-conservative force - work done against friction is path dependent, in the presence of friction, some energy is always lost in the form of heat. Thus mechanical energy is not conserved, the Greeks, including Aristotle, Vitruvius, and Pliny the Elder, were interested in the cause and mitigation of friction. They were aware of differences between static and kinetic friction with Themistius stating in 350 A. D. that it is easier to further the motion of a moving body than to move a body at rest. The classic laws of sliding friction were discovered by Leonardo da Vinci in 1493, a pioneer in tribology and these laws were rediscovered by Guillaume Amontons in 1699. Amontons presented the nature of friction in terms of surface irregularities, the understanding of friction was further developed by Charles-Augustin de Coulomb. Coulomb further considered the influence of sliding velocity, temperature and humidity, the distinction between static and dynamic friction is made in Coulombs friction law, although this distinction was already drawn by Johann Andreas von Segner in 1758. Leslie was equally skeptical about the role of adhesion proposed by Desaguliers, in Leslies view, friction should be seen as a time-dependent process of flattening, pressing down asperities, which creates new obstacles in what were cavities before
36.
Ductility
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In materials science, ductility is a solid materials ability to deform under tensile stress, this is often characterized by the materials ability to be stretched into a wire. Malleability, a property, is a materials ability to deform under compressive stress. Both of these properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Also, these properties are dependent on temperature and pressure. Ductility and malleability are not always coextensive – for instance, while gold has high ductility and malleability, lead has low ductility, the word ductility is sometimes used to encompass both types of plasticity. Ductility is especially important in metalworking, as materials that crack, break or shatter under stress cannot be manipulated using metal-forming processes such as hammering, rolling, malleable materials can be formed cold using stamping or pressing, whereas brittle materials may be cast or thermoformed. High degrees of ductility occur due to bonds, which are found predominantly in metals. In metallic bonds valence shell electrons are delocalized and shared between many atoms, the delocalized electrons allow metal atoms to slide past one another without being subjected to strong repulsive forces that would cause other materials to shatter. Ductility can be quantified by the fracture strain ε f, which is the strain at which a test specimen fractures during a uniaxial tensile test. Another commonly used measure is the reduction of area at fracture q, the ductility of steel varies depending on the alloying constituents. Increasing levels of carbon decrease ductility, many plastics and amorphous solids, such as Play-Doh, are also malleable. The most ductile metal is platinum and the most malleable metal is gold, DBTT is important since, once a material is cooled below the DBTT, it has a much greater tendency to shatter on impact instead of bending or deforming. For example, zamak 3 exhibits good ductility at room temperature, DBTT is a very important consideration in selecting materials that are subjected to mechanical stresses. A similar phenomenon, the transition temperature, occurs with glasses and polymers. In some materials the transition is sharper than others and typically requires a temperature-sensitive deformation mechanism and this can be problematic for steels with a high ferrite content. This famously resulted in serious hull cracking in Liberty ships in colder waters during World War II, DBTT can also be influenced by external factors such as neutron radiation, which leads to an increase in internal lattice defects and a corresponding decrease in ductility and increase in DBTT. The most accurate method of measuring the DBTT of a material is by fracture testing, typically four point bend testing at a range of temperatures is performed on pre-cracked bars of polished material. For experiments conducted at higher temperatures, dislocation activity increases, the temperature at which this occurs is the ductile–brittle transition temperature
37.
Humid continental climate
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Precipitation is usually well distributed through the year. Some climatologists prefer to use the 0 °C isotherm as it is commonly used. In addition, the location in question must not be semi-arid or arid, humid continental climates tend to be found between latitudes 40° N and 60° N, within the central and northeastern portions of North America, Europe, and Asia. They are much less commonly found in the Southern Hemisphere due to the ocean area at that latitude. More extreme humid continental climates found in southern Siberia and the American Midwest combine hotter summer maxima, climatological averages are used to determine which locations are within a certain climate regime. The World Meteorological Organization has defined this average as through a 30 year period, the version from 1936 utilized a mean temperature of the coldest month of below −3 °C and there must be at least four months whose mean temperatures are at or above 10 °C. In Europe, the −3 °C average temperature isotherm was near the extent of winter snowpack. Many climatologists in the U. S. prefer to use 0 °C as the standard because they feel it better reflects consistency in regional landscapes, the 10 °C average temperature was found to be the minimum temperature necessary for the tree growth. Large temperature ranges are common within this climate zone, in addition, the location in question must not be semi-arid or arid. This is from an update to the climate regime definition introduced by Trewartha & Horn in 1980, despite the 1980 update, climate regimes are essentially the same within the Southern Hemisphere. The largest changes are seen in North America, Europe, under Köppen, the following variants of this climate are possible. The climate regime uses a three letter code, beginning with the letter D. Otherwise, The second letter f , s , A dry summer — the driest summer month has at most 30 millimetres of rainfall and has at most 1⁄3 the precipitation of the wettest winter month. W , A dry winter — the driest winter month has at most one‑tenth of the found in the wettest summer month. The third letter a , Warmest month averages above 22 °C b , Does not meet the requirements for a, within North America, moisture within this climate regime is supplied by the Gulf of Mexico and adjacent western subtropical Atlantic. Snowfall occurs in all areas with a continental climate and in many such places is more common than rain during the height of winter. In places with sufficient wintertime precipitation, the cover is often deep. Most summer rainfall occurs during thunderstorms, and in North America, though humidity levels are often high in locations with humid continental climates, the humid designation means that the climate is not dry enough to be classified as semi-arid or arid. By definition, forests thrive within this climate, biomes within this climate regime include temperate woodlands, temperate grasslands, temperate deciduous, temperature evergreen forests, and coniferous forests
38.
Oceanic climate
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Oceanic climates are defined as having a monthly mean temperature below 22 °C in the warmest month, and above 0 °C in the coldest month. It typically lacks a dry season, as precipitation is evenly dispersed throughout the year. Oceanic climates generally have cool summers and mild to cool winters, Oceanic climates are most dominant in Europe, where they spread much farther inland than in other continents. Oceanic climates can have much storm activity as they are located in the belt of the stormy westerlies, many oceanic climates have frequent cloudy or overcast conditions due to the near constant storms and lows tracking over or near them. Precipitation is both adequate and reliable throughout the year in oceanic climates, extended months of rain and cloudy conditions are common in oceanic climates. Seattle is an example of this, between October and May, Seattle experiences high rainfall and is mostly or partly cloudy six out of every seven days. In most areas with a climate, precipitation comes in the form of rain for the majority of the year. However, some areas with this climate see some snowfall annually during winter, outside of Australia and parts of New Zealand, most areas with an oceanic climate experience at least one snowstorm per year. In the poleward locations of the climate zone, snowfall is more frequent. Overall temperature characteristics of the oceanic climates feature cool temperatures and infrequent extremes of temperature, summers are cool, with the warmest month having a mean temperature below 22 °C. Poleward of the latter is a zone of the subpolar oceanic climate, with long and cold winters and cool. Examples of this climate include parts of coastal Iceland in the Northern Hemisphere and extreme southern Chile, Oceanic climates are not necessarily always found in coastal locations on the aforementioned parallels, however, in most cases oceanic climates parallel higher middle latitude oceans. The polar jet stream, which moves in a west to east direction across the middle latitudes, advancing low pressure systems, storms, in coastal areas of the higher middle latitudes, the prevailing onshore flow creates the basic structure of most oceanic climates. Oceanic climates are a product and reflection of the adjacent to them. In summer, high pressure pushes the prevailing westerlies north of many oceanic climates. As a result of the Gulf Stream, west-coast areas located in high latitudes like Ireland, the UK, Oceanic climates in Europe occur mostly in Northwest Europe, from Ireland and Great Britain eastward to central Europe. Most of France, Germany, Norway, the north coast of Spain, examples of oceanic climates are found in London, Bergen, Dublin, Berlin, Bilbao, Donostia-San Sebastian, Biarritz, Bayonne, Zürich, Copenhagen and Paris. With decreasing distance to the Mediterranean Sea, the climate of Northwest Europe gradually changes to the subtropical dry-summer or Mediterranean climate of southern Europe
39.
Radar
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Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the objects location and speed. Radar was developed secretly for military use by several nations in the period before, the term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging or RAdio Direction And Ranging. The term radar has since entered English and other languages as a common noun, high tech radar systems are associated with digital signal processing, machine learning and are capable of extracting useful information from very high noise levels. Other systems similar to make use of other parts of the electromagnetic spectrum. One example is lidar, which uses ultraviolet, visible, or near infrared light from lasers rather than radio waves, as early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects. In 1895, Alexander Popov, an instructor at the Imperial Russian Navy school in Kronstadt. The next year, he added a spark-gap transmitter, in 1897, while testing this equipment for communicating between two ships in the Baltic Sea, he took note of an interference beat caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon might be used for detecting objects, the German inventor Christian Hülsmeyer was the first to use radio waves to detect the presence of distant metallic objects. In 1904, he demonstrated the feasibility of detecting a ship in dense fog and he obtained a patent for his detection device in April 1904 and later a patent for a related amendment for estimating the distance to the ship. He also got a British patent on September 23,1904 for a radar system. It operated on a 50 cm wavelength and the radar signal was created via a spark-gap. In 1915, Robert Watson-Watt used radio technology to advance warning to airmen. Watson-Watt became an expert on the use of direction finding as part of his lightning experiments. As part of ongoing experiments, he asked the new boy, Arnold Frederic Wilkins, Wilkins made an extensive study of available units before selecting a receiver model from the General Post Office. Its instruction manual noted that there was fading when aircraft flew by, in 1922, A. Hoyt Taylor and Leo C. Taylor submitted a report, suggesting that this might be used to detect the presence of ships in low visibility, eight years later, Lawrence A. Australia, Canada, New Zealand, and South Africa followed prewar Great Britain, and Hungary had similar developments during the war. Hugon, began developing a radio apparatus, a part of which was installed on the liner Normandie in 1935
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Chisholm, Hugh, ed. (1911). "Avalanche". Encyclopædia Britannica (11th ed.). Cambridge University Press. But note the myths cited above
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