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49-699: Ettaler Manndl is a 1636-meter-high mountain of the Ammergau Alps in Bavaria , Germany . It is close to the town of Oberammergau , above Ettal , and about 10 km north of Garmisch-Partenkirchen . It is a sub-peak of the Laber mountain at 1681 m. The mountain is a popular destination for hiking and in Winter, skiing is also possible. A cable car (the Laberbergbahn) brings visitors up to just below

98-518: A bad drainage system were blamed for its creation. It swallowed a three-story building and a house; it measured approximately 20 m (66 ft) wide and 30 m (98 ft) deep. A similar hole had formed nearby in February 2007. This large vertical hole is not a true sinkhole, as it did not form via the dissolution of limestone, dolomite, marble, or any other water-soluble rock. Instead, they are examples of "piping pseudokarst", created by

147-809: A gross underestimate based on inadequate data. The greatest amount of karst sinkhole damage in the United States occurs in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. The largest recent sinkhole in the USA is possibly one that formed in 1972 in Montevallo, Alabama , as a result of man-made lowering of the water level in a nearby rock quarry. This "December Giant" or "Golly Hole" sinkhole measures 130 m (425 ft) long, 105 m (350 ft) wide and 45 m (150 ft) deep. Other areas of significant karst hazards include

196-519: A high likelihood of snow in winter. Each there on the first weekend in February the famous King Ludgwig Race ( König-Ludwig-Lauf ) takes place. Downhill skiing is possible in Oberammergau, Bad Kohlgrub and Unterammergau. In Bad Kohlgrub there is a 4.5-kilometre-long bobsleigh run on the Hörnle. In summer there is a large network of paths and trails, for example: A large part of the range forms

245-514: A relatively monotone topography. By contrast, the northern part is more varied and has a complicated stratigraphic sequence of. Here, although there is still dolomite in smaller areas, the predominant rock is Wetterstein limestone . The Ammergauer Hochplatte and the Säuling are the most impressive mountains made from this rock. In addition, small patches of argillite , marl , sandstones , radiolarite , conglomerates and gravel limestones enrich

294-533: A small area, giving the landscape a pock-marked appearance. These sinkholes drain all the water, so there are only subterranean rivers in these areas. Examples of karst landscapes with numerous massive sinkholes include Khammouan Mountains ( Laos ) and Mamo Plateau (Papua New Guinea). The largest known sinkholes formed in sandstone are Sima Humboldt and Sima Martel in Venezuela . Some sinkholes form in thick layers of homogeneous limestone. Their formation

343-543: A very dense network of forest tracks . In many areas (e.g. on the Friederspitz ), intensive grazing of sheep has caused problems as a result of the destruction of grassy alpine mountainside by erosion . Unlike the neighbouring mountain ranges to the west and southwest, the Ammergau Alps only have a few pastures and alms . The majority of the range is covered in forest. This is due to the fact that large parts of

392-515: Is also the county boundary between Garmisch-Partenkirchen and Ostallgäu , runs from south to north through the Ammergau Alps. Geologically the Ammergau Alps are mostly composed of Main Dolomite , which forms striking summits like the Kreuzspitze . Generally dolomite underlies the whole southern section of the range with the exception of small pockets of plattenkalk , which is why it has

441-612: Is facilitated by high groundwater flow, often caused by high rainfall; such rainfall causes formation of the giant sinkholes in the Nakanaï Mountains , on the New Britain island in Papua New Guinea. Powerful underground rivers may form on the contact between limestone and underlying insoluble rock, creating large underground voids. In such conditions, the largest known sinkholes of the world have formed, like

490-488: Is sometimes used to refer to doline , enclosed depressions that are also known as shakeholes , and to openings where surface water enters into underground passages known as ponor , swallow hole or swallet . A cenote is a type of sinkhole that exposes groundwater underneath. Sink , and stream sink are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock. Most sinkholes are caused by karst processes –

539-695: Is subsidence due to subterranean human activity, such as mining and military trenches . Examples have included, instances above World War I trenches in Ypres , Belgium ; near mines in Nitra , Slovakia ; a limestone quarry in Dudley , England; and above an old gypsum mine in Magheracloone , Ireland . Some of the largest sinkholes in the world are: [REDACTED]  This article incorporates public domain material from websites or documents of

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588-490: Is the pollution of groundwater resources, with serious health implications in such areas. The Maya civilization sometimes used sinkholes in the Yucatán Peninsula (known as cenotes ) as places to deposit precious items and human sacrifices. When sinkholes are very deep or connected to caves, they may offer challenges for experienced cavers or, when water-filled, divers . Some of the most spectacular are

637-420: Is well understood, and proper site characterization can avoid karst disasters. Thus most sinkhole disasters are predictable and preventable rather than " acts of God ". The American Society of Civil Engineers has declared that the potential for sinkhole collapse must be a part of land-use planning in karst areas. Where sinkhole collapse of structures could cause loss of life, the public should be made aware of

686-489: The Rosetta space probe . Collapses, commonly incorrectly labeled as sinkholes, also occur due to human activity, such as the collapse of abandoned mines and salt cavern storage in salt domes in places like Louisiana , Mississippi and Texas , in the United States of America. More commonly, collapses occur in urban areas due to water main breaks or sewer collapses when old pipes give way. They can also occur from

735-568: The Ebro Basin in northern Spain ; the island of Sardinia ; the Italian peninsula; the Chalk areas in southern England ; Sichuan , China ; Jamaica ; France ; Croatia ; Bosnia and Herzegovina ; Slovenia ; and Russia , where one-third of the total land area is underlain by karst. Sinkholes tend to occur in karst landscapes. Karst landscapes can have up to thousands of sinkholes within

784-720: The Graswangtal ). The most intensive examples are in the area of the Kreuzspitze and on the north flanks of the southern main chain of mountains. The Friedergries and the Lindergries are particularly notable areas of deposition in the valleys. One unusual topographic feature is the Kessel , a large doline funnel in the area of the Hasentalkopf , that was deepened as a result of the loosening of rock. The ecology of

833-743: The Plansee and the Heiterwanger See the Ammergau Alps have two of the most attractive lakes in the Austrian state of Tyrol. The lakes are located in valleys (a rarity in the Northern Limestone Alps) and cut fjord -like into the forested mountainsides. Their shores are almost undeveloped. Other lakes occur on the northwestern edge of the range (the Alpsee , Schwansee and Forggensee ). At around two dozen boggy depressions in

882-1117: The Zacatón cenote in Mexico (the world's deepest water-filled sinkhole), the Boesmansgat sinkhole in South Africa, Sarisariñama tepuy in Venezuela, the Sótano del Barro in Mexico, and in the town of Mount Gambier, South Australia . Sinkholes that form in coral reefs and islands that collapse to enormous depths are known as blue holes and often become popular diving spots. Large and visually unusual sinkholes have been well known to local people since ancient times. Nowadays sinkholes are grouped and named in site-specific or generic names. Some examples of such names are listed below. The 2010 Guatemala City sinkhole formed suddenly in May of that year; torrential rains from Tropical Storm Agatha and

931-423: The collapse of a cave roof, or a lowering of the water table . Sinkholes often form through the process of suffosion . For example, groundwater may dissolve the carbonate cement holding the sandstone particles together and then carry away the lax particles, gradually forming a void. Occasionally a sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, such as

980-573: The 288 km Ammergau Alps Nature Reserve ( Naturschutzgebiet Ammergebirge ), the largest reserve in Bavaria. In the Bavarian part of the Ammergau Alps there are three Alpine Club huts. In the Tyrolean part of the mountains there are no Alpine Club huts at all. Sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term

1029-520: The 662-metre-deep (2,172 ft) Xiaozhai Tiankeng ( Chongqing , China), giant sótanos in Querétaro and San Luis Potosí states in Mexico and others. Unusual processes have formed the enormous sinkholes of Sistema Zacatón in Tamaulipas (Mexico), where more than 20 sinkholes and other karst formations have been shaped by volcanically heated, acidic groundwater. This has produced not only

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1078-487: The Ammergau Alps were a royal hunting area and also that dolomite and flysch soils create unsuitable conditions for alm and grassland cultivation. Dolomite produces thin, dry soils and flysch is too prone to landslips. There are buildings of international renown in the Ammergau Alps. These include the castles of Linderhof and Neuschwanstein as well as Ettal Abbey . To the north the Alpine Foreland forms

1127-518: The Ammergau Alps, Alpine mountain pine raised bogs are excavated and supplied to the spa facilities and "wellness" hotels in the region. The mosses and lichens in the Ammer valley and its surrounding area are due to the last ice age which ended about 10,000 years ago. Forestry is the human activity that most dominates the landscape and which has changed the natural appearance of forests and woodlands, in some cases, significantly. It has also established

1176-665: The Ammergau are found on the main, southern, crest (the Daniel ridge or Danielkamm ). The most diverse and touristically interesting part of the Ammergau Alps is in the Hochplatten-Tegelberg Group. The ten highest peaks of the Ammergau Alps: In the Ammergau Alps there are just under 200 named peaks with spot heights. Amongst the better known are (in order of height): The Ammergau Alps border on

1225-682: The Ehrwald Basin and the Reutte Basin ( Talkessel ). The Zwischentoren valley forms a barely noticeable pass that links the Ammergau Alps to the Lechtal Alps . The Alpine Club guide, Alpenvereinsführer Allgäuer Alpen und Ammergauer Alpen , divides the Ammergau Alps into the following sub-groups: The Kreuzspitze Group with its Kreuzspitze and the Geierköpfen are the most alpine part of the Ammergau Alps. The highest peaks in

1274-667: The Minyé sinkhole in Papua New Guinea or Cedar Sink at Mammoth Cave National Park in Kentucky , an underground stream or river may be visible across its bottom flowing from one side to the other. Sinkholes are common where the rock below the land surface is limestone or other carbonate rock , salt beds , or in other soluble rocks, such as gypsum , that can be dissolved naturally by circulating ground water . Sinkholes also occur in sandstone and quartzite terrains. As

1323-461: The boundary from the river Lech to the river Loisach . The Lech forms the boundary in the west from its exit into the Alpine Foreland downstream as far as Reutte. The Loisach borders the Ammergau Alps in the east , southeast and south from its exit into the Alpine Foreland upstream as far as the Ehrwald Basin. To the southwest the valley of the Zwischentoren forms the link between

1372-757: The chemical dissolution of carbonate rocks , collapse or suffosion processes. Sinkholes are usually circular and vary in size from tens to hundreds of meters both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide. Sinkholes may capture surface drainage from running or standing water, but may also form in high and dry places in specific locations. Sinkholes that capture drainage can hold it in large limestone caves. These caves may drain into tributaries of larger rivers. The formation of sinkholes involves natural processes of erosion or gradual removal of slightly soluble bedrock (such as limestone ) by percolating water,

1421-437: The collapse of cavities in soil that have developed where soil falls down into underlying rock cavities, pose the most serious hazards to life and property. Fluctuation of the water level accelerates this collapse process. When water rises up through fissures in the rock, it reduces soil cohesion . Later, as the water level moves downward, the softened soil seeps downwards into rock cavities. Flowing water in karst conduits carries

1470-675: The collapse of large cavities that had developed in the weak, crumbly Quaternary volcanic deposits underlying the city. Although weak and crumbly, these volcanic deposits have enough cohesion to allow them to stand in vertical faces and to develop large subterranean voids within them. A process called " soil piping " first created large underground voids, as water from leaking water mains flowed through these volcanic deposits and mechanically washed fine volcanic materials out of them, then progressively eroded and removed coarser materials. Eventually, these underground voids became large enough that their roofs collapsed to create large holes. A crown hole

1519-405: The downward movement of water beyond the natural rate of groundwater recharge. The increased runoff from the impervious surfaces of roads, roofs, and parking lots also accelerate man-induced sinkhole collapses. Some induced sinkholes are preceded by warning signs, such as cracks, sagging, jammed doors, or cracking noises, but others develop with little or no warning. However, karst development

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1568-639: The following other mountain ranges in the Alps: To the north the Ammergau Alps border on the Alpine Foreland . The Via Alpina , a cross-border, long distance path with five stages across the whole Alps, also runs through the Ammergau Alps. The Violet Way of the Via Alpina has 3 stages and runs through the range as follows: In the valleys between Unterammergau , Oberammergau , Ettal and Schloss Linderhof there are numerous loipe s with

1617-489: The formation of the deepest water-filled sinkhole in the world— Zacatón —but also unique processes of travertine sedimentation in upper parts of sinkholes, leading to sealing of these sinkholes with travertine lids. The U.S. state of Florida in North America is known for having frequent sinkhole collapses, especially in the central part of the state. Underlying limestone there is from 15 to 25 million years old. On

1666-494: The fringes of the state, sinkholes are rare or non-existent; limestone there is around 120,000 years old. The Murge area in southern Italy also has numerous sinkholes. Sinkholes can be formed in retention ponds from large amounts of rain. On the Arctic seafloor, methane emissions have caused large sinkholes to form. Sinkholes have been used for centuries as disposal sites for various forms of waste . A consequence of this

1715-459: The land surface and natural drainage. Since water level changes accelerate sinkhole collapse, measures must be taken to minimize water level changes. The areas most susceptible to sinkhole collapse can be identified and avoided. In karst areas the traditional foundation evaluations ( bearing capacity and settlement ) of the ability of soil to support a structure must be supplemented by geotechnical site investigation for cavities and defects in

1764-620: The landscape. Near the edge of the Alps, however, flysch appears over wide areas ( Hohe Bleick , Hörnle ) and, because of its susceptibility to erosion, forms rounded, frequently densely wooded mountains more typical of the Central Uplands . The widespread occurrence of dolomite results in the typical appearance of much of the Ammergau Alps: great streams of dolomite scree, the so-called Gries , which fills entire valleys (such as

1813-444: The natural dissolution of rock. The U.S. Geological Survey notes that "It is a frightening thought to imagine the ground below your feet or house suddenly collapsing and forming a big hole in the ground." Human activities can accelerate collapses of karst sinkholes, causing collapse within a few years that would normally evolve over thousands of years under natural conditions. Soil-collapse sinkholes, which are characterized by

1862-415: The northern Alpine region here in the Ammergau Alps. Of internationaler significance are the diverse raised bogs and fens . Certain woodland communities are also very valuable such as the unique boulder and ravine and forests or coloured reed grass and pine woods. Extensive meadow cultivation on calcareous grassland , wet meadows and matgrass meadows further enrich the flora of the Ammergau Alps. In

1911-560: The northern perimeter - the Tegelberg and Laber Bergbahn - and three chair lifts : to the Buchenberg , Hörnle and Kolben Saddle. In the central and southern areas there are no lifts or accommodation huts at all. The Ammergau Alps are a relatively natural, undeveloped range with a very low population density . It is the largest Bavarian nature reserve . The border between the Bavarian provinces of Upper Bavaria and Swabia , which

1960-417: The overpumping and extraction of groundwater and subsurface fluids. Sinkholes can also form when natural water-drainage patterns are changed and new water-diversion systems are developed. Some sinkholes form when the land surface is changed, such as when industrial and runoff-storage ponds are created; the substantial weight of the new material can trigger a collapse of the roof of an existing void or cavity in

2009-495: The perimeter of the mountains. The Ammergau Alps are an ideal region for the average walker thanks to the comparatively low height of their summits and their location on the northern edge of the Alps with its proximity to the population centres of south Germany. Most of the summits are accessible within a day's round trip from bases in the valleys. As a result, there is only a small number of Alpine Club huts . Neither are there many cable cars or lifts. There are just two cable cars on

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2058-601: The region is important because of the constant shifting of the Griese , the dolomitic screes, because this dynamic supports the existence of rare plants. In the Friedergries, for example, the rare Spirke tree grows, a species exclusively dependent on frequent movements of scree. In addition, many other rare plants occur here. The snowbell ( Soldanella minima ssp. minima ) and Mount Baldo sedge ( Carex baldensis ), which are predominantly southern Alpine species, only occur in

2107-499: The risks. The most likely locations for sinkhole collapse are areas where there is already a high density of existing sinkholes. Their presence shows that the subsurface contains a cave system or other unstable voids. Where large cavities exist in the limestone large surface collapses can occur, such the Winter Park, Florida sinkhole collapse . Recommendations for land uses in karst areas should avoid or minimize alterations of

2156-414: The rock dissolves, spaces and caverns develop underground. These sinkholes can be dramatic, because the surface land usually stays intact until there is not enough support. Then, a sudden collapse of the land surface can occur. On 2 July 2015, scientists reported that active pits, related to sinkhole collapses and possibly associated with outbursts, were found on the comet 67P/Churyumov-Gerasimenko by

2205-512: The soil away, preventing soil from accumulating in rock cavities and allowing the collapse process to continue. Induced sinkholes occur where human activity alters how surface water recharges groundwater . Many human-induced sinkholes occur where natural diffused recharge is disturbed and surface water becomes concentrated. Activities that can accelerate sinkhole collapses include timber removal, ditching, laying pipelines, sewers, water lines, storm drains, and drilling. These activities can increase

2254-467: The soil to create larger surface depressions. Cover-collapse sinkholes or "dropouts" form where so much soil settles down into voids in the limestone that the ground surface collapses. The surface collapses may occur abruptly and cause catastrophic damages. New sinkhole collapses can also form when human activity changes the natural water-drainage patterns in karst areas. Pseudokarst sinkholes resemble karst sinkholes but are formed by processes other than

2303-441: The subsurface, resulting in development of a sinkhole. Solution or dissolution sinkholes form where water dissolves limestone under a soil covering. Dissolution enlarges natural openings in the rock such as joints, fractures, and bedding planes. Soil settles down into the enlarged openings forming a small depression at the ground surface. Cover-subsidence sinkholes form where voids in the underlying limestone allow more settling of

2352-671: The summit of the Laber, from where a variety of footpaths lead. There is also a restaurant at the top cable car station. This Bavaria location article is a stub . You can help Misplaced Pages by expanding it . Ammergau Alps The Ammergau Alps are a cross-border range shared between the German Free State of Bavaria (ca. 3/4 of the area) and the Austrian state of Tyrol . The towns of Füssen , Oberammergau , Garmisch-Partenkirchen , Ehrwald and Reutte lie around

2401-428: The underlying rock. Since the soil/rock surface in karst areas are very irregular the number of subsurface samples ( borings and core samples ) required per unit area is usually much greater than in non-karst areas. In 2015, the U.S. Geological Survey estimated the cost for repairs of damage arising from karst-related processes as at least $ 300 million per year over the preceding 15 years, but noted that this may be

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