Norway the Kingdom of Norway, is a Nordic country in Northern Europe whose territory comprises the western and northernmost portion of the Scandinavian Peninsula. The Antarctic Peter I Island and the sub-Antarctic Bouvet Island are dependent territories and thus not considered part of the kingdom. Norway lays claim to a section of Antarctica known as Queen Maud Land. Norway has a total area of 385,207 square kilometres and a population of 5,312,300; the country shares a long eastern border with Sweden. Norway is bordered by Finland and Russia to the north-east, the Skagerrak strait to the south, with Denmark on the other side. Norway has an extensive coastline, facing the Barents Sea. Harald V of the House of Glücksburg is the current King of Norway. Erna Solberg has been prime minister since 2013. A unitary sovereign state with a constitutional monarchy, Norway divides state power between the parliament, the cabinet and the supreme court, as determined by the 1814 constitution; the kingdom was established in 872 as a merger of a large number of petty kingdoms and has existed continuously for 1,147 years.
From 1537 to 1814, Norway was a part of the Kingdom of Denmark-Norway, from 1814 to 1905, it was in a personal union with the Kingdom of Sweden. Norway was neutral during the First World War. Norway remained neutral until April 1940 when the country was invaded and occupied by Germany until the end of Second World War. Norway has both administrative and political subdivisions on two levels: counties and municipalities; the Sámi people have a certain amount of self-determination and influence over traditional territories through the Sámi Parliament and the Finnmark Act. Norway maintains close ties with both the United States. Norway is a founding member of the United Nations, NATO, the European Free Trade Association, the Council of Europe, the Antarctic Treaty, the Nordic Council. Norway maintains the Nordic welfare model with universal health care and a comprehensive social security system, its values are rooted in egalitarian ideals; the Norwegian state has large ownership positions in key industrial sectors, having extensive reserves of petroleum, natural gas, lumber and fresh water.
The petroleum industry accounts for around a quarter of the country's gross domestic product. On a per-capita basis, Norway is the world's largest producer of oil and natural gas outside of the Middle East; the country has the fourth-highest per capita income in the world on the World IMF lists. On the CIA's GDP per capita list which includes autonomous territories and regions, Norway ranks as number eleven, it has the world's largest sovereign wealth fund, with a value of US$1 trillion. Norway has had the highest Human Development Index ranking in the world since 2009, a position held between 2001 and 2006, it had the highest inequality-adjusted ranking until 2018 when Iceland moved to the top of the list. Norway ranked first on the World Happiness Report for 2017 and ranks first on the OECD Better Life Index, the Index of Public Integrity, the Democracy Index. Norway has one of the lowest crime rates in the world. Norway has two official names: Norge in Noreg in Nynorsk; the English name Norway comes from the Old English word Norþweg mentioned in 880, meaning "northern way" or "way leading to the north", how the Anglo-Saxons referred to the coastline of Atlantic Norway similar to scientific consensus about the origin of the Norwegian language name.
The Anglo-Saxons of Britain referred to the kingdom of Norway in 880 as Norðmanna land. There is some disagreement about whether the native name of Norway had the same etymology as the English form. According to the traditional dominant view, the first component was norðr, a cognate of English north, so the full name was Norðr vegr, "the way northwards", referring to the sailing route along the Norwegian coast, contrasting with suðrvegar "southern way" for, austrvegr "eastern way" for the Baltic. In the translation of Orosius for Alfred, the name is Norðweg, while in younger Old English sources the ð is gone. In the 10th century many Norsemen settled in Northern France, according to the sagas, in the area, called Normandy from norðmann, although not a Norwegian possession. In France normanni or northmanni referred to people of Sweden or Denmark; until around 1800 inhabitants of Western Norway where referred to as nordmenn while inhabitants of Eastern Norway where referred to as austmenn. According to another theory, the first component was a word nór, meaning "narrow" or "northern", referring to the inner-archipelago sailing route through the land.
The interpretation as "northern", as reflected in the English and Latin forms of the name, would have been due to folk etymology. This latter view originated with philologist Niels Halvorsen Trønnes in 1847; the form Nore is still used in placenames such as the village of Nore and lake Norefjorden in Buskerud county, still has the same meaning. Among other arguments in favour of the theor
Guangxi (. A province, Guangxi became an autonomous region in 1958. Guangxi's location, in mountainous terrain in the far south of China, has placed it on the frontier of Chinese civilization throughout much of China's history; the current name "Guang" means "expanse" and has been associated with the region since the creation of Guang Prefecture in 226 AD. It was given provincial level status during the Yuan dynasty, but into the 20th century it was considered an open, wild territory; the abbreviation of the region is "桂", which comes from the name of the city of Guilin, the provincial capital during the Ming and Qing dynasties. The current capital is Nanning. "Guǎng" means "expanse" or "vast", has been associated with the region since the creation of Guang Prefecture in AD 226. Guangxi and neighboring Guangdong mean "expanse west" and "expanse east". Together and Guangdong are called Loeng gwong. During the Song dynasty, the Two Guangs were formally separated as Guǎngnán Xīlù and Guǎngnán Dōnglù, which became abbreviated as Guǎngxī Lù and Guǎngdōng Lù.
Inhabited by a mixture of tribal groups known to the Chinese as the Baiyue, the region first became part of China during the Qin dynasty. In 214 BC, the Han Chinese general Zhao Tuo claimed most of southern China for Qin Shi Huang before the emperor's death; the ensuing civil war permitted Zhao to establish a separate kingdom at Panyu known as Nanyue. Alternatively submissive to and independent of Han dynasty control, Southern Yue expanded colonization and sinicization under its policy of "Harmonizing and Gathering the Hundred Yue" until its collapse in 111 BC during the southward expansion of the Han dynasty; the name "Guangxi" can be traced to the "Expansive" or "Wide" province of the Eastern Wu, who controlled southeastern China during the Three Kingdoms period. Guilin formed one of its commanderies. Under the Tang dynasty, the Zhuang moved to support Piluoge's kingdom of Nanzhao in Yunnan, which repulsed imperial armies in 751 and 754. Guangxi was divided into an area of Zhuang ascendancy west of Nanning and an area of Han ascendancy east of Nanning.
After the collapse of the Southern Zhao, Liu Yan established the Southern Han in Xingwangfu. Although this state gained minimal control over Guangxi, it was plagued by instability and annexed by the Song dynasty in 971; the name "Guangxi" itself can be traced to the Song, who administered the area as the Guangnanxi Circuit. Harassed by both Song and the Jiaozhi in modern Vietnam, the Zhuang leader Nong Zhigao led a revolt in 1052 for which he is still remembered by the Zhuang people, his independent kingdom was short-lived and the tattooed Song general Di Qing returned Guangxi to China. The Yuan dynasty established control over Yunnan during its conquest of the Dali Kingdom in 1253 and eliminated the Southern Song following the Battle of Yamen in 1279. Rather than ruling Lingnan as a subject territory or military district, the Mongolians established Guangxi as a proper province; the area nonetheless continued to be unruly, leading the Ming dynasty to employ the different local groups against one another.
At the Battle of Big Rattan Gorge between the Zhuang and the Yao in 1465, 20,000 deaths were reported. During the Ming and Qing dynasty, parts of Guangxi were ruled by the powerful Cen clan; the Cen were recognized as tusi or local ruler by the Chinese emperors. The Qing dynasty left the region alone until the imposition of direct rule in 1726, but the 19th century was one of constant unrest. A Yao revolt in 1831 was followed the Jintian Uprising in January 1851 and the Da Cheng Rebellion in April 1854; the execution of St. Auguste Chapdelaine by local officials in Guangxi provoked the Second Opium War in 1858 and the legalization of foreign interference in the interior. Although Louis Brière de l'Isle was unable to invade its depot at Longzhou, the Guangxi Army saw a great deal of action in the 1884 Sino-French War. Ineffective within Vietnam, it was still able to repulse the French from China itself at the Battle of Zhennan Pass on 23 March 1885. Following the Wuchang Uprising, Guangxi seceded from the Qing Empire on 6 November 1911.
The Qing governor, Shen Bingdan remained in place, but was subsequently removed by a mutiny commanded by General Lu Rongting. General Lu's Old Guangxi clique overran Hunan and Guangdong as well and helped lead the National Protection War against Yuan Shikai's attempt to re-establish an imperial government. Zhuang loyalty made his Self-Government Army cohesive but reluctant to move far beyond its own provinces. Subsequent feuding with Sun Yat-sen led to defeat in the 1921 Guangdong -- Guangxi War. After a brief occupation by Chen Jiongming's Cantonese forces, Guangxi fell into disunity and profound banditry for several years until Li Zongren's Guangxi Pacification Army established the New Guangxi clique dominated by Li, Huang Shaohong, Bai Chongxi. Successful action in Hunan against Wu Peif
Guilin romanized as Kweilin, is a prefecture-level city in the northeast of China's Guangxi Zhuang Autonomous Region. It is situated on the west bank of the Li borders Hunan to the north, its name means "Forest of Sweet Osmanthus", owing to the large number of fragrant sweet osmanthus trees located in the region. The city has long been renowned for its scenery of karst topography and is one of China's most popular tourist destinations. Relics found in the city's Baojiyan and Zengpiyan caves that dates back to 10,000 years ago; the Zengpiyan people had a matriarchal clan society. Before the Qin dynasty, Guilin region was settled by the Baiyue people. In 314 BC, a small settlement was established along the banks of the Li River. During the Qin dynasty's campaigns against the state of Nanyue, the first administration was set up in the area around Guilin; the modern city was located within the Guilin Commandery, origin of the modern name "Guilin". In 111 BC, during the reign of Emperor Wu of the Han dynasty, Shi'an County was established, which could be regarded as the beginning of the city.
In AD 507, the town was renamed Guizhou. In 634, Lingui County was established under Gui Prefecture. In 868, Pang Xun rebelled against the Tang from Gui Prefecture. Guilin remained a county; the city was a nexus between the central government and the southwest border, it was where regular armies were placed to guard that border. Canals were built through the city so that food supplies could be directly transported from the food-productive Yangtze plain to the farthest southwestern point of the empire. In 997, Guangnan West Circuit, predecessor of modern Guangxi, was established, with Guizhou as the capital. In 1133, Guizhou was renamed Jingjiang Prefecture. In 1367, the name was changed to Guilin Prefecture. In 1921, Guilin became one of the headquarters of the Northern Expeditionary Army led by Sun Yat-sen. In 1940, Guilin City was established. In 1950, the provincial capital of Guangxi was moved from Guilin to Nanning. In 1981, Guilin was listed by the State Council as one of the four cities where the protection of historical and cultural heritage, as well as natural scenery, should be treated as a priority project.
Guilin administers seventeen county-level divisions, including 6 districts, 8 counties, 2 autonomous counties, 1 county-level city. District: Xiufeng District Xiangshan District Diecai District Qixing District Yanshan District Lingui District County-level city: Lipu city County: Yangshuo County Lingchuan County Xing'an County Quanzhou County Yongfu County Ziyuan County Guanyang County Pingle County Autonomous county: Gongcheng Yao Autonomous County Longsheng Various Nationalities Autonomous County Guilin is located in northern Guangxi, bordering Liuzhou to the west, Laibin to the southwest, Wuzhou to the south, Hezhou to the southeast, within neighbouring Hunan, Huaihua to the northwest, Shaoyang to the north, Yongzhou to the east, it has a total area of 27,809 square kilometres. The topography of the area is marked by karst formations; the Li River flows through the city. Hills and mountains: Diecai Hill, Elephant Trunk Hill, Wave-Subduing Hill, Lipu Mountains, Kitten Mountain, the highest peak of Guangxi, Yao Hill Caves: Reed Flute Cave, Seven-Star Cave Guilin has a monsoon-influenced humid subtropical climate, with short, mild winters, long, humid summers.
Winter becomes progressively wetter and cloudier. Spring is overcast and rainy, while summer continues to be rainy though is the sunniest time of year. Autumn is dry; the monthly 24-hour average temperature ranges from 8.1 °C in January to 28.2 °C in July, the annual mean is 19.12 °C. The annual rainfall is just above 1,888 mm, is delivered in bulk from April to June, when the plum rains occur and create the risk of flooding. With monthly percent possible sunshine ranging from 14% in March to 53% in September, the city receives 1,487 hours of bright sunshine annually. Population: 4,747,963 Urban population: 975,638 Ethnic groups: Zhuang, Hui, Miao and Dong The GDP per capita was ¥19435 in 2009, ranked no. 125 among 659 Chinese cities. Local industries: condoms, pharmaceutical goods, machinery, silk, wine, cinnamon, herbal medicine Local agricultural products: Shatian Pomelo, summer orange, Fructus Momordicae, moon persimmon, Lipu Taro, Sanhua Alcohol, pepper sauce, fermented bean curd, Guilin Rice Noodle, water chestnut, grain and dried bean milk cream in tight rollsUntil 1949 only a thermal power plant, a cement works, some small textile mills existed as signs of industrialization in Guilin.
However, since the 1950s Guilin has electronics and agricultural equipment, medicine and buses, it has textile and cotton yarn factories. Food processing, including the processing of local agricultural produce, remains the most important industry. More recent and modern industry feature high technology and the tertiary industry characterized by tourism trading and service; the airport is Guilin Liangjiang International Airport. Airlines that fly to the airport are: China Eastern Asiana Airlines China Southern Air China H
China the People's Republic of China, is a country in East Asia and the world's most populous country, with a population of around 1.404 billion. Covering 9,600,000 square kilometers, it is the third- or fourth-largest country by total area. Governed by the Communist Party of China, the state exercises jurisdiction over 22 provinces, five autonomous regions, four direct-controlled municipalities, the special administrative regions of Hong Kong and Macau. China emerged as one of the world's earliest civilizations, in the fertile basin of the Yellow River in the North China Plain. For millennia, China's political system was based on hereditary monarchies, or dynasties, beginning with the semi-legendary Xia dynasty in 21st century BCE. Since China has expanded, re-unified numerous times. In the 3rd century BCE, the Qin established the first Chinese empire; the succeeding Han dynasty, which ruled from 206 BC until 220 AD, saw some of the most advanced technology at that time, including papermaking and the compass, along with agricultural and medical improvements.
The invention of gunpowder and movable type in the Tang dynasty and Northern Song completed the Four Great Inventions. Tang culture spread in Asia, as the new Silk Route brought traders to as far as Mesopotamia and Horn of Africa. Dynastic rule ended in 1912 with the Xinhai Revolution; the Chinese Civil War resulted in a division of territory in 1949, when the Communist Party of China established the People's Republic of China, a unitary one-party sovereign state on Mainland China, while the Kuomintang-led government retreated to the island of Taiwan. The political status of Taiwan remains disputed. Since the introduction of economic reforms in 1978, China's economy has been one of the world's fastest-growing with annual growth rates above 6 percent. According to the World Bank, China's GDP grew from $150 billion in 1978 to $12.24 trillion by 2017. Since 2010, China has been the world's second-largest economy by nominal GDP and since 2014, the largest economy in the world by purchasing power parity.
China is the world's largest exporter and second-largest importer of goods. China is a recognized nuclear weapons state and has the world's largest standing army and second-largest defense budget; the PRC is a permanent member of the United Nations Security Council as it replaced the ROC in 1971, as well as an active global partner of ASEAN Plus mechanism. China is a leading member of numerous formal and informal multilateral organizations, including the Shanghai Cooperation Organization, WTO, APEC, BRICS, the BCIM, the G20. In recent times, scholars have argued that it will soon be a world superpower, rivaling the United States; the word "China" has been used in English since the 16th century. It is not a word used by the Chinese themselves, it has been traced through Portuguese and Persian back to the Sanskrit word Cīna, used in ancient India."China" appears in Richard Eden's 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. Barbosa's usage was derived from Persian Chīn, in turn derived from Sanskrit Cīna.
Cīna was first used including the Mahābhārata and the Laws of Manu. In 1655, Martino Martini suggested that the word China is derived from the name of the Qin dynasty. Although this derivation is still given in various sources, it is complicated by the fact that the Sanskrit word appears in pre-Qin literature; the word may have referred to a state such as Yelang. The meaning transferred to China as a whole; the origin of the Sanskrit word is still a matter of debate, according to the Oxford English Dictionary. The official name of the modern state is the "People's Republic of China"; the shorter form is "China" Zhōngguó, from zhōng and guó, a term which developed under the Western Zhou dynasty in reference to its royal demesne. It was applied to the area around Luoyi during the Eastern Zhou and to China's Central Plain before being used as an occasional synonym for the state under the Qing, it was used as a cultural concept to distinguish the Huaxia people from perceived "barbarians". The name Zhongguo is translated as "Middle Kingdom" in English.
Archaeological evidence suggests that early hominids inhabited China between 2.24 million and 250,000 years ago. The hominid fossils of Peking Man, a Homo erectus who used fire, were discovered in a cave at Zhoukoudian near Beijing; the fossilized teeth of Homo sapiens have been discovered in Fuyan Cave in Hunan. Chinese proto-writing existed in Jiahu around 7000 BCE, Damaidi around 6000 BCE, Dadiwan from 5800–5400 BCE, Banpo dating from the 5th millennium BCE; some scholars have suggested. According to Chinese tradition, the first dynasty was the Xia, which emerged around 2100 BCE; the dynasty was considered mythical by historians until scientific excavations found early Bronze Age sites at Erlitou, Henan in 1959. It remains unclear whether these sites are the remains of the Xia dynasty or of another culture from the same period; the succeeding Shang dynasty is the earliest to be confirmed by contemporary records. The Shang ruled the plain of the Yellow River in eastern China from the 17th to the 11th century BCE.
Their oracle bone script
Torghatten is a granite mountain on the island of Torget in Brønnøy Municipality in Nordland county, Norway. It is known for natural tunnel, through its center, it is possible to walk up to the tunnel on a well-prepared path, through it on a natural path. On 6 May 1988, Widerøe Flight 710 from Namsos to Brønnøysund crashed into the side of the mountain, all the 36 passengers and crew died. According to legend, the hole was made by the troll Hestmannen while he was chasing the beautiful girl Lekamøya; as the troll realized he would not get the girl, he released an arrow to kill her, but the troll-king of Sømna threw his hat into the arrow's path to save her. The hat turned into the mountain with a hole in the middle. Felice Vinci has linked the legends about Torghatten to the Homeric myth of Polyphemus; the tunnel is 160 metres long, 20 metres wide, 35 metres high. It was formed during the Scandinavian ice age. Ice and water eroded the looser rocks, while the harder ones in the mountain top have resisted erosion.
Moon Hill, in Yangshuo County Elephant Trunk Hill, in Guilin Brønnøy municipality website about Torghatten
Rock climbing is a sport in which participants climb up, down or across natural rock formations or artificial rock walls. The goal is to reach the summit of a formation or the endpoint of a pre-defined route without falling. Professional rock climbing competitions have the objectives of either completing the route in the quickest possible time or attaining the farthest point on an difficult route. Due to the length of time and extended endurance required, because accidents are most to happen on the descent, rock climbers do not climb back down the route, or "downclimb" on the larger multiple pitch class III–IV, or multi-day grade IV–VI climbs. Rock climbing is a physically and mentally demanding sport, one that tests a climber's strength, endurance and balance along with mental control, it can be a dangerous activity and knowledge of proper climbing techniques and use of specialized climbing equipment is crucial for the safe completion of routes. Because of the wide range and variety of rock formations around the world, rock climbing has been separated into several different styles and sub-disciplines, such as scrambling, another activity involving the scaling of hills and similar formations, differentiated by rock climbing's sustained use of hands to support the climber's weight as well as to provide balance.
Paintings dating from 200 BC show Chinese men rock climbing. In early America, the cliff-dwelling Anasazi in the 12th century are thought to have been excellent climbers. Early European climbers used rock climbing techniques as a skill required to reach the summit in their mountaineering exploits. In the 1880s, European rock climbing became an independent pursuit outside of mountain climbing. Although rock climbing was an important component of Victorian mountaineering in the Alps, it is thought that the sport of rock climbing began in the last quarter of the nineteenth century in various parts of Europe. Rock climbing evolved from an alpine necessity to a distinct athletic activity. Aid climbing, climbing using equipment that acts as artificial handhold or footholds, became popular during the period 1920–1960, leading to ascents in the Alps and in Yosemite Valley that were considered impossible without such means. However, climbing techniques and ethical considerations have evolved steadily.
Today, free climbing, climbing using holds made of natural rock while using gear for protection and not for upward movement, is the most popular form of the sport. Free climbing has since been divided into several sub-styles of climbing dependent on belay configuration. Over time, grading systems have been created in order to compare more the relative difficulties of the rock climbs. In How to Rock Climb, John Long notes that for moderately skilled climbers getting to the top of a route is not enough. Within free climbing, there are distinctions given to ascents: on-sight and redpoint. To on-sight a route is to ascend the wall without aid or any foreknowledge, it is considered the way to climb with the most style. Flashing is similar to on-sighting, except that the climber has previous information about the route including talking about the beta with other climbers. Redpointing means to make a free ascent of the route after having first tried it. Style is up to each individual climber and among climbers the verbiage and definitions can differ.
Most of the climbing done in modern times is considered free climbing—climbing using one's own physical strength, with equipment used as protection and not as support—as opposed to aid climbing, the gear-dependent form of climbing, dominant in the sport's earlier days. Free climbing is divided into several styles that differ from one another depending on the choice of equipment used and the configurations of their belay and anchor systems; as routes get higher off the ground, the increased risk of life-threatening injuries necessitates additional safety measures. A variety of specialized climbing techniques and climbing equipment exists to provide that safety. Climbers will work in pairs and utilize a system of ropes and anchors designed to catch falls. Ropes and anchors can be configured in different ways to suit many styles of climbing, roped climbing are thus divided into further sub-types that vary based on how their belay systems are set up. Speaking, beginners will start with top roping and/or easy bouldering and work their way up to lead climbing and beyond.
Still the most popular method of climbing big walls, aid climbers make progress up a wall by placing and weighting gear, used directly to aid ascent and enhance safety. This form of climbing is used when ascent is too technically difficult or impossible for free climbing; the most used method to ascend climbs refers to climbs where the climber's own physical strength and skill are relied on to accomplish the climb. Free climbing may rely on top rope belay systems, or on lead climbing to establish protection and the belay stations. Anchors and protection are used to back up the climber and are passive as opposed to active ascending aids. Subtypes of free climbing are trad sport climbing. Free climbing is done as "clean lead" meaning no pitons or pins are used as protection. Climbing on short, low routes without the use of the safety rope, typical of most other styles. Protection, if used at all consists of a cushioned bouldering pad below the route and a spotter, a person who watches from below and directs the fall of the climber away from hazardous areas.
Bouldering may be an arena for intense and safe competition, resulting in exceptionally high diffic
Karst is a topography formed from the dissolution of soluble rocks such as limestone and gypsum. It is characterized by underground drainage systems with caves, it has been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no lakes. However, in regions where the dissolved bedrock is covered or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and be missing above ground; the study of karst is considered of prime importance in petroleum geology because as much as 50% of the world's hydrocarbon reserves are hosted in porous karst systems. The English word karst was borrowed from German Karst in the late 19th century, which entered German much earlier. According to one interpretation the term is derived from the German name for a number of geological and hydrological features found within the range of the Dinaric Alps, stretching from the northeastern corner of Italy above the city of Trieste, across the Balkan peninsula along the coast of the eastern Adriatic to Kosovo and North Macedonia, where the massif of the Šar Mountains begins, more the karst zone at the northwestern-most section, described in early topographical research as a plateau, between Italy and Slovenia.
In the local South Slavic languages, all variations of the word are derived from a Romanized Illyrian base metathesized from the reconstructed form *korsъ into forms such as Bosnian: krš, Croatian: krš, kraš, Serbian: kras, Slovene: kras. Languages preserving the older, non-metathesized form include Italian: Carso, German: Karst, Albanian: karsti; the Slovene common noun kras was first attested in the 18th century, the adjective form kraški in the 16th century. As a proper noun, the Slovene form Grast was first attested in 1177; the word is of Mediterranean origin. It has been suggested that the word may derive from the Proto-Indo-European root karra-'rock'; the name may be connected to the oronym Karsádios oros cited by Ptolemy, also to Latin Carusardius. Johann Weikhard von Valvasor, a pioneer of the study of karst in Slovenia and a fellow of the Royal Society for Improving Natural Knowledge, introduced the word karst to European scholars in 1689, describing the phenomenon of underground flows of rivers in his account of Lake Cerknica.
Jovan Cvijić advanced the knowledge of karst regions, so much that he became known as the "father of karst geomorphology". Discussing the karstic regions of the Balkans, Cvijić's 1893 publication Das Karstphänomen describes landforms such as karren and poljes. In a 1918 publication, Cvijić proposed a cyclical model for karstic landscape development. Karst hydrology emerged as a discipline in early 1960s in France; the activities of cave explorers, called speleologists, had been dismissed as more of a sport than a science, meaning that underground karstic caves and their associated watercourses were, from a scientific perspective, understudied. The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, or bedding planes; as the bedrock continues to degrade, its cracks tend to get bigger. As time goes on, these fractures will become wider, a drainage system of some sort may start to form underneath. If this underground drainage system does form, it will speed up the development of karst formations there because more water will be able to flow through the region, giving it more erosive power.
The carbonic acid that causes karstic features is formed as rain passes through Earth's atmosphere picking up carbon dioxide, which dissolves in the water. Once the rain reaches the ground, it may pass through soil that can provide much more CO2 to form a weak carbonic acid solution, which dissolves calcium carbonate; the primary reaction sequence in limestone dissolution is the following: In particular and rare conditions such as encountered in the past in Lechuguilla Cave in New Mexico, other mechanisms may play a role. The oxidation of sulfides leading to the formation of sulfuric acid can be one of the corrosion factors in karst formation; as oxygen -rich surface waters seep into deep anoxic karst systems, they bring oxygen, which reacts with sulfide present in the system to form sulfuric acid. Sulfuric acid reacts with calcium carbonate, causing increased erosion within the limestone formation; this chain of reactions is: This reaction chain forms gypsum. The karstification of a landscape may result in a variety of large- or small-scale features both on the surface and beneath.
On exposed surfaces, small features may include solution flutes, limestone pavement, collectively called karren or lapiez. Medium-sized surface features may include sinkholes or cenotes, vertical shafts, disappearing streams, reappearing springs. Large-scale features may include limestone pavements and karst valleys. Mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground drainage systems and extensive caves and cavern systems may form. Erosion along limes