Misplaced Pages

#327672

39-692: The Thorung La pass, at 5,415 meters above sea level, connects the district with Mustang district by providing a route between the towns of Manang and Muktinath . Manang district gets the lowest amount of rainfall among the districts of Nepal as it lies to the north of the Himalayas , which block monsoon winds. The Manang Valley, which lies close to the Nepal-Tibet border, offers tremendous opportunities due to its rich natural flora and fauna. Three tracks start from here. The first, via Thorangla, Muktinath, and Mustang to Lhasa—a journey that takes four days;

78-611: A 300 km (190 mi) route around the Annapurna mountain range. In addition to trekkers , the pass is regularly used by local traders. Most trekkers cross the pass from east to west (Manang to Muktinath), which is the easiest and safest direction. It is not possible to cross Thorong La from Manang to Muktinath in one day. Trekkers usually spend the first night in Yak Kharka and the second night in Thorong Phedi — which

117-409: A defined barometric pressure . Generally, the pressure used to set the altimeter is the barometric pressure that would exist at MSL in the region being flown over. This pressure is referred to as either QNH or "altimeter" and is transmitted to the pilot by radio from air traffic control (ATC) or an automatic terminal information service (ATIS). Since the terrain elevation is also referenced to MSL,

156-432: A few metres, in timeframes ranging from minutes to months: Between 1901 and 2018, the average sea level rose by 15–25 cm (6–10 in), with an increase of 2.3 mm (0.091 in) per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities

195-438: A reference datum for mean sea level (MSL). It is also used in aviation, where some heights are recorded and reported with respect to mean sea level (contrast with flight level ), and in the atmospheric sciences , and in land surveying . An alternative is to base height measurements on a reference ellipsoid approximating the entire Earth, which is what systems such as GPS do. In aviation, the reference ellipsoid known as WGS84

234-470: A sharp reduction in greenhouse gas emissions, this may increase to hundreds of millions in the latter decades of the century. Local factors like tidal range or land subsidence will greatly affect the severity of impacts. For instance, sea level rise in the United States is likely to be two to three times greater than the global average by the end of the century. Yet, of the 20 countries with

273-417: Is an average surface level of one or more among Earth 's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datum  – a standardised geodetic datum  – that is used, for example, as a chart datum in cartography and marine navigation , or, in aviation, as the standard sea level at which atmospheric pressure

312-488: Is because the sea is in constant motion, affected by the tides, wind , atmospheric pressure, local gravitational differences, temperature, salinity , and so forth. The mean sea level at a particular location may be calculated over an extended time period and used as a datum . For example, hourly measurements may be averaged over a full Metonic 19-year lunar cycle to determine the mean sea level at an official tide gauge . Still-water level or still-water sea level (SWL)

351-427: Is due to change in either the volume of water in the world's oceans or the volume of the oceanic basins . Two major mechanisms are currently causing eustatic sea level rise. First, shrinking land ice, such as mountain glaciers and polar ice sheets, is releasing water into the oceans. Second, as ocean temperatures rise, the warmer water expands. Many factors can produce short-term changes in sea level, typically within

390-561: Is filled with snowfall of 1 to 3 inches and the temperature remains between negative 3 to 7 degrees Celcius. After a heavy blizzard from Cyclone Hudhud about forty people, including trekkers, guides and locals, were killed around Thorong La. Hampered by 1.8 meters of snow within twelve hours and disruption of cell service in the Manang District, local forces were able to rescue ca. 300 people by helicopter. Sea level Mean sea level ( MSL , often shortened to sea level )

429-483: Is increasingly used to define heights; however, differences up to 100 metres (328 feet) exist between this ellipsoid height and local mean sea level. Another alternative is to use a geoid -based vertical datum such as NAVD88 and the global EGM96 (part of WGS84). Details vary in different countries. When referring to geographic features such as mountains, on a topographic map variations in elevation are shown by contour lines . A mountain's highest point or summit

SECTION 10

#1732780883328

468-512: Is measured to calibrate altitude and, consequently, aircraft flight levels . A common and relatively straightforward mean sea-level standard is instead a long-term average of tide gauge readings at a particular reference location. Sea levels can be affected by many factors and are known to have varied greatly over geological time scales . Current sea level rise is mainly caused by human-induced climate change . When temperatures rise, mountain glaciers and polar ice sheets melt, increasing

507-556: Is situated at 4,540 metres (14,895 ft), or at Thorong High Camp — which is situated at 4,880 metres (16,010 ft) before attempting to go over Thorong La. Choosing this option decreases the elevation gain and loss for that day's hike, as well as decreasing the distance. The staff of the Himalayan Rescue Association post in Manang recommends that trekkers spend five nights between their arrival in Manang and

546-450: Is the level of the sea with motions such as wind waves averaged out. Then MSL implies the SWL further averaged over a period of time such that changes due to, e.g., the tides , also have zero mean. Global MSL refers to a spatial average over the entire ocean area, typically using large sets of tide gauges and/or satellite measurements. One often measures the values of MSL with respect to

585-727: Is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise , with another 42% resulting from thermal expansion of water . Sea level rise lags behind changes in the Earth 's temperature by many decades, and sea level rise will therefore continue to accelerate between now and 2050 in response to warming that has already happened. What happens after that depends on human greenhouse gas emissions . If there are very deep cuts in emissions, sea level rise would slow between 2050 and 2100. It could then reach by 2100 slightly over 30 cm (1 ft) from now and approximately 60 cm (2 ft) from

624-531: Is typically illustrated with the AMSL height in metres, feet or both. In unusual cases where a land location is below sea level, such as Death Valley, California , the elevation AMSL is negative. It is often necessary to compare the local height of the mean sea surface with a "level" reference surface, or geodetic datum, called the geoid . In the absence of external forces, the local mean sea level would coincide with this geoid surface, being an equipotential surface of

663-680: The Annapurna Himal, in central Nepal . Thorong Ri is on the slope of Khatung Kang and Yakawa Kang are the mountains forming Thorong La. The pass is located on a trail that connects the village of Manang in the Manang District to the east, with the temple of Muktinath and the nearby village of Ranipauwa , in the Mustang District to the west. Thorong La is the highest point on the Annapurna Circuit ,

702-622: The geoid of the Earth, which approximates the local mean sea level for locations in the open ocean. The geoid includes a significant depression in the Indian Ocean , whose surface dips as much as 106 m (348 ft) below the global mean sea level (excluding minor effects such as tides and currents). Precise determination of a "mean sea level" is difficult because of the many factors that affect sea level. Instantaneous sea level varies substantially on several scales of time and space. This

741-418: The height above mean sea level (AMSL). The term APSL means above present sea level, comparing sea levels in the past with the level today. Earth's radius at sea level is 6,378.137 km (3,963.191 mi) at the equator. It is 6,356.752 km (3,949.903 mi) at the poles and 6,371.001 km (3,958.756 mi) on average. This flattened spheroid , combined with local gravity anomalies , defines

780-562: The 1690s. Satellite altimeters have been making precise measurements of sea level since the launch of TOPEX/Poseidon in 1992. A joint mission of NASA and CNES , TOPEX/Poseidon was followed by Jason-1 in 2001 and the Ocean Surface Topography Mission on the Jason-2 satellite in 2008. Height above mean sea level ( AMSL ) is the elevation (on the ground) or altitude (in the air) of an object, relative to

819-973: The 19th century. With high emissions it would instead accelerate further, and could rise by 1.0 m ( 3 + 1 ⁄ 3  ft) or even 1.6 m ( 5 + 1 ⁄ 3  ft) by 2100. In the long run, sea level rise would amount to 2–3 m (7–10 ft) over the next 2000 years if warming stays to its current 1.5 °C (2.7 °F) over the pre-industrial past. It would be 19–22 metres (62–72 ft) if warming peaks at 5 °C (9.0 °F). Rising seas affect every coastal and island population on Earth. This can be through flooding, higher storm surges , king tides , and tsunamis . There are many knock-on effects. They lead to loss of coastal ecosystems like mangroves . Crop yields may reduce because of increasing salt levels in irrigation water. Damage to ports disrupts sea trade. The sea level rise projected by 2050 will expose places currently inhabited by tens of millions of people to annual flooding. Without

SECTION 20

#1732780883328

858-448: The Earth's gravitational field which, in itself, does not conform to a simple sphere or ellipsoid and exhibits gravity anomalies such as those measured by NASA's GRACE satellites . In reality, the geoid surface is not directly observed, even as a long-term average, due to ocean currents, air pressure variations, temperature and salinity variations, etc. The location-dependent but time-persistent separation between local mean sea level and

897-712: The Manangies spend as much as six months away from home, returning only during the summers. Many of them reside in Kathmandu, where their children study in English-medium schools. The parents' lack of proficiency in the English language is irrelevant as it in no way affects their trading skills. Since the area was opened to outsiders in the late 1970s, many have switched from the traditional agriculture to hoteleering. The trail from Manang to Muktinath has been used by

936-705: The Marégraphe in Marseilles measures continuously the sea level since 1883 and offers the longest collated data about the sea level. It is used for a part of continental Europe and the main part of Africa as the official sea level. Spain uses the reference to measure heights below or above sea level at Alicante , while the European Vertical Reference System is calibrated to the Amsterdam Peil elevation, which dates back to

975-533: The altitude. For trekkers choosing this direction of travel, the last place where it is possible to spend the night is located at Ranipauwa, where there is a lodge situated at 3,670 metres (12,041 ft). There is also a very basic lodge located at Muktinath Phedi, situated at 4,190 metres (13,747 ft), but this lodge is only open seasonally. Trekkers going from west to east must therefore ascend at least 1,230 metres (4,035 ft) and descend at least 540 metres (1,772 ft) in one day. The safest months to cross

1014-456: The amount of water in the oceans, while the existing seawater also expands with heat. Because most of human settlement and infrastructure was built in response to a more-normalized sea level with limited expected change, populations affected by sea level rise will need to invest in climate adaptation to mitigate the worst effects or, when populations are at extreme risk, a process of managed retreat . The term above sea level generally refers to

1053-440: The crossing to Muktinath. The additional time spent in Manang allows trekkers to acclimatize sufficiently to minimize the risk of acute mountain sickness (AMS). The Himalayan Rescue Association operates a medical clinic at Manang, and periodically a small outpost at Thorong Phedi. The route from west to east (Muktinath to Manang) is much more difficult, because it does not allow most trekkers sufficient time for acclimatization to

1092-482: The geoid is referred to as (mean) ocean surface topography . It varies globally in a typical range of ±1 m (3 ft). Several terms are used to describe the changing relationships between sea level and dry land. The melting of glaciers at the end of ice ages results in isostatic post-glacial rebound , when land rises after the weight of ice is removed. Conversely, older volcanic islands experience relative sea level rise, due to isostatic subsidence from

1131-634: The greatest exposure to sea level rise, twelve are in Asia , including Indonesia , Bangladesh and the Philippines. The resilience and adaptive capacity of ecosystems and countries also varies, which will result in more or less pronounced impacts. The greatest impact on human populations in the near term will occur in the low-lying Caribbean and Pacific islands . Sea level rise will make many of them uninhabitable later this century. Pilots can estimate height above sea level with an altimeter set to

1170-555: The height of planetary features. Local mean sea level (LMSL) is defined as the height of the sea with respect to a land benchmark, averaged over a period of time long enough that fluctuations caused by waves and tides are smoothed out, typically a year or more. One must adjust perceived changes in LMSL to account for vertical movements of the land, which can occur at rates similar to sea level changes (millimetres per year). Some land movements occur because of isostatic adjustment to

1209-591: The land; hence a change in relative MSL or ( relative sea level ) can result from a real change in sea level, or from a change in the height of the land on which the tide gauge operates, or both. In the UK, the ordnance datum (the 0 metres height on UK maps) is the mean sea level measured at Newlyn in Cornwall between 1915 and 1921. Before 1921, the vertical datum was MSL at the Victoria Dock, Liverpool . Since

Manang District, Nepal - Misplaced Pages Continue

1248-1209: The locals for hundreds of years to transport huge herds of sheep and yak in and out of Manang. It is an important route for the people of the region. The northern parts of Manang Valley are dry, brown and desolate places, very different from the thick forests and brown green valleys of Sikkim and Eastern Nepal. At the time of the 2011 Nepal census , Manang District had a population of 6,538. As their first language , 62.3% spoke Gurung , 16.2% Nepali , 8.1% Tamang , 7.4% Sherpa , 1.2% Magar , 0.9% Newari , 0.9% Thakali , 0.4% Kham , 0.3% Sign language , 0.2% Bhojpuri , 0.2% Bote , 0.2% Rai and 1.6% other languages. Ethnicity/caste: 57.1% were Gurung , 12.6% Tamang , 7.1% Ghale , 6.9% Bhote , 3.8% Kami , 2.5% Hill Brahmin , 2.3% Magar , 1.5% Chhetri , 1.5% Newar , 0.9% Damai /Dholi, 0.9% Thakali , 0.5% Rai , 0.3% Sherpa , 0.2% Bote, 0.2% Sarki and 1.6% others. Religion: 55.2% were Buddhist , 39.2% Hindu , 1.4% Christian , 0.5% Bon , 0.2% Prakriti , 0.1% Muslim and 3.4% others. Literacy: 72.0% could read and write, 0.7% could only read and 27.3% could neither read nor write. The district consists of four rural municipalities : Prior to

1287-481: The melting of ice sheets at the end of the last ice age . The weight of the ice sheet depresses the underlying land, and when the ice melts away the land slowly rebounds . Changes in ground-based ice volume also affect local and regional sea levels by the readjustment of the geoid and true polar wander . Atmospheric pressure , ocean currents and local ocean temperature changes can affect LMSL as well. Eustatic sea level change (global as opposed to local change)

1326-444: The pass are March–May and September–November. Attempting to cross Thorong La at other times of the year is dangerous due to the increased risk of avalanches , frostbite and the likelihood of a storm or a whiteout , which can cause trekkers to become disoriented and lost. Trekkers usually depart Thorung Pedi / Thorung High camp a few hours before sunrise, as strong winds typically begin a few hours after sunrise. The local climate on

1365-486: The restructuring of the district, Manang District consisted of the following municipalities and village development committees : 28°33′7″N 84°14′27″E  /  28.55194°N 84.24083°E  / 28.55194; 84.24083 Thorung La Thorong La or Thorung La is a mountain pass with an elevation of 5,416 metres (17,769 ft) above sea level in the Damodar Himal , north of

1404-711: The second via Naur Khola and Naurgaon, which takes five days to Lhasa; and the third via Larkiya bazar, which is the one most commonly used by the people of Central Nepal. Along with the Marwaris who have migrated from India to Nepal in large numbers, the Manangies are the best known traders of Nepal. They have received special dispensation from the King to trade in South East Asia, and travel abroad with precious stones and metals, musk, herbs and other items. They import ready-made garments, watches and electronic goods. Many of

1443-518: The times of the Russian Empire , in Russia and its other former parts, now independent states, the sea level is measured from the zero level of Kronstadt Sea-Gauge. In Hong Kong, "mPD" is a surveying term meaning "metres above Principal Datum" and refers to height of 0.146 m (5.7 in) above chart datum and 1.304 m (4 ft 3.3 in) below the average sea level. In France,

1482-411: The weight of cooling volcanos. The subsidence of land due to the withdrawal of groundwater is another isostatic cause of relative sea level rise. On planets that lack a liquid ocean, planetologists can calculate a "mean altitude" by averaging the heights of all points on the surface. This altitude, sometimes referred to as a "sea level" or zero-level elevation , serves equivalently as a reference for

1521-406: The western side of the pass is much drier than on the eastern side. There is practically no vegetation on the western side, except where irrigated, while in the Manang valley, there is much more vegetation and cultivation is possible, while it is still fairly dry, as the valley is protected from the wet southern monsoon winds by the Annapurna mountain range. From December to February, Thorong la Pass

#327672