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Tsergo Ri Landslide
The Tsergo Ri landslide was a prehistoric landslide in the Nepalese Himalaya, which took place around 51,000±13,000 years ago, during the Last Glacial Period. During the collapse, a mass of rock of about detached from a previous mountain or ridge and descended with a speed of about ; later, glaciers eroded almost the entire landslide mass. Previously weakened rocks may have contributed to the collapse, which was probably started by an earthquake. Geomorphology and geology The collapse of Tsergo Ri took place in Nepal's Langtang valley, perpendicular to the Himalaya and about north of the Nepalese capital Kathmandu. The small settlement of Kyangjin Kharka lies at the foot of the landslide deposit. With a volume of , it is one of the largest known mass movements on Earth and perhaps the largest known landslide in crystalline bedrock. Causes and trigger The collapse affected Himalayan gneiss rocks, which also contain migmatites and granites; they also include older pseudotachyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nepal
Nepal (; ne, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne, सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain, bordering the Tibet Autonomous Region of China to the north, and India in the south, east, and west, while it is narrowly separated from Bangladesh by the Siliguri Corridor, and from Bhutan by the Indian state of Sikkim. Nepal has a diverse geography, including fertile plains, subalpine forested hills, and eight of the world's ten tallest mountains, including Mount Everest, the highest point on Earth. Nepal is a multi-ethnic, multi-lingual, multi-religious and multi-cultural state, with Nepali as the official language. Kathmandu is the nation's capital and the largest city. The name "Nepal" is first recorded in texts from the Vedic period of the India ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Central Thrust
The Main Central Thrust is a major geological fault where the Indian Plate has pushed under the Eurasian Plate along the Himalaya. The fault slopes down to the north and is exposed on the surface in a NW-SE direction (strike). It is a thrust fault that continues along 2900 km of the Himalaya mountain belt.Upreti, B. N.An overview of the stratigraphy and tectonics of the Nepal Himalaya ''Journal of Asian Earth Sciences'' 17.5 (1994): 577–606. The generally accepted definition of the Main Central Thrust is that it is a ductile shear zone along which the High-grade Great Himalayan Crystalline complex was placed above the low-grade to unmetamorphosed Lesser Himalayan Sequence.Helm, A., and A. Gansser. "Central Himalaya, Geological observations of the Swiss expedition 1936." ''Memoires de la Societe Helvetique des Sciences Naturelles'' 73.1,245 (1939). However, this definition is not perfect because of many difficulties and complications defining the Main Central Thrust. Many geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology. Typically, groundwater is thought of as water flowing through shallow aquifers, but, in the technical sense, it can also contain soil moisture, perma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radon
Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colourless, odourless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into various short-lived radioactive elements and lead. Radon itself is the immediate decay product of radium. Its most stable isotope, 222Rn, has a half-life of only 3.8 days, making it one of the rarest elements. Since thorium and uranium are two of the most common radioactive elements on Earth, while also having three isotopes with half-lives on the order of several billion years, radon will be present on Earth long into the future despite its short half-life. The decay of radon produces many other short-lived nuclides, known as "radon daughters", ending at stable isotopes of lead. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mudflow
A mudflow or mud flow is a form of mass wasting involving fast-moving flow of debris that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significant proportion of clay, which makes them more fluid than debris flows, allowing them to travel farther and across lower slope angles. Both types of flow are generally mixtures of particles with a wide range of sizes, which typically become sorted by size upon deposition. 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; such events are often called flow slides. Other types of mudflows include lahars (involving fine-grained pyroclastic deposits on the flanks of volcanoes) and jökulhlaups (outbursts from under glaciers or icecaps). A statutory definition of "flood-related muds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2015 Nepal Earthquake
The April 2015 Nepal earthquake (also known as the Gorkha earthquake) killed 8,964 people and injured 21,952 more. It occurred at on Saturday, 25 April 2015, with a magnitude of 7.8Moment magnitude scale, Mw or 8.1Surface wave magnitude, Ms and a maximum Mercalli intensity scale, Mercalli Intensity of X (''Extreme''). Its epicenter was east of Gorkha District at Barpak, Gorkha, roughly northwest of central Kathmandu, and its hypocenter was at a depth of approximately . It was the worst natural disaster to strike Nepal since the 1934 Nepal–Bihar earthquake. The ground motion recorded in Kathmandu, capital of Nepal, was of low frequency, which, along with its occurrence at an hour where many people in rural areas were working outdoors, decreased the loss of property and human lives. The earthquake triggered 2015 Mount Everest avalanches, an avalanche on Mount Everest, killing 22, the deadliest incident on the mountain on record. The earthquake triggered another huge avalanche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Langtang Lirung
Langtang Lirung is the highest peak of the Langtang Himal Range, which is a subrange of the Nepalese Himalayas, southwest of the Eight-thousander Shishapangma. The List of the world's highest 100 mountains puts it at number 99. Location The Langtang Himal forms the western portion of a complex of mountains which also includes the Jugal Himal, home of Shishapangma. This complex lies between the Sun Kosi valley on the east and the Trisuli Gandaki valley on the west. Langtang Lirung lies near the Trisuli Gandaki, and north of the Langtang Khola. At a distance of 4km towards the east, Tsangbu Ri is located. Features Though not high by the standards of major Himalayan peaks, Langtang Lirung is notable for its large vertical relief above local terrain. For example, it rises above the Trisuli Gandaki to the west in only . It has a large south face which long resisted climbing attempts. Climbing history The peak was reconnoitered by H. W. Tilman and P. Lloyd in 1949. Attempts were m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yala Peak
Yala Peak is a mountain in the Langtang area in Nepal. Location The summit of the peak is located at above sea level and it provides a vantage point from where Shishapangma , , can be seen. The Tsergo Ri giant landslide occurred close to Yala Peak. This peak is considered as a trekking peak by the Nepal Mountaineering Association, and is a relatively simple, non-technical climb. The climbing of Yala Peak passes through the Langtang National Park. The flora and fauna of the peak and surrounding area consist of Rhododendron, Snow leopard, and Red panda The red panda (''Ailurus fulgens''), also known as the lesser panda, is a small mammal native to the eastern Himalayas and southwestern China. It has dense reddish-brown fur with a black belly and legs, white-lined ears, a mostly white muzzle .... In its first leg, climbers choose to go to Kyanjin Monastery , a famous Buddhist pilgrimage place, to adjust to the altitude and climate. Once acclimatized, the climbers move t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Würm Glaciation
The Würm glaciation or Würm stage (german: Würm-Kaltzeit or ''Würm-Glazial'', colloquially often also ''Würmeiszeit'' or ''Würmzeit''; cf. ice age), usually referred to in the literature as the Würm (often spelled "Wurm"), was the last glacial period in the Alpine region. It is the youngest of the major glaciations of the region that extended beyond the Alps themselves. Like most of the other ice ages of the Pleistocene epoch, it is named after a river, in this case the Würm in Bavaria, a tributary of the Amper. The Würm ice age can be dated to about 115,000 to 11,700 years ago, but sources differ about the dates, depending on whether the long transition phases between the glacials and interglacials (warmer periods) are allocated to one or other of those periods. The average annual temperatures during the Würm ice age in the Alpine Foreland were below −3 °C (today +7 °C). That has been determined from changes in the vegetation (pollen analysis), as well a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate between glacial periods. The Last Glacial Period ended about 15,000 years ago. The Holocene is the current interglacial. A time with no glaciers on Earth is considered a greenhouse climate state. Quaternary Period Within the Quaternary, which started about 2.6 million years before present, there have been a number of glacials and interglacials. At least eight glacial cycles have occurred in the last 740,000 years alone. Penultimate Glacial Period The Penultimate Glacial Period (PGP) is the glacial period that occurred before the Last Glacial Period. It began about 194,000 years ago and ended 135,000 years ago, with the beginning of the Eemian interglacial. Last Glacial Period The last glacial period was the most recent glacial period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from conglomerate because the rock fragments have sharp edges that have not been worn down. These indicate that the gravel was deposited very close to its source area, since otherwise th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debris Avalanche
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally have bulk densities comparable to those of rock avalanches and other types of landslides (roughly 2000 kilograms per cubic meter), but owing to widespread sediment liquefaction caused by high pore-fluid pressures, they can flow almost as fluidly as water. Debris flows descending steep channels commonly attain speeds that surpass 10 m/s (36 km/h), although some large flows can reach speeds that are much greater. Debris flows with volumes ranging up to about 100,000 cubic meters occur frequently in mountainous regions worldwide. The largest prehistoric flows have had volumes exceeding 1 billion cubic meters (i.e., 1 cubic kilometer). As a result of their high sediment concentrations and mobility, debris flows can be very dest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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