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Maars
A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow crater lake which may also be called a maar. The name comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany. Notes: * According to German Wikipedia's ''"Maar"'' article, in 1544 in his book ''Cosmographia'', Sebastian Münster (1488–1552) first applied the word "maar" (as ''Marh'') to the Ulmener Maar and the Laacher See. See: Sebastian Münster, ''Cosmographia'' (Basel, Switzerland: Heinrich Petri, 1544)p. 341. From p. 341: ''"Item zwen namhafftiger seen seind in der Eyfel / einer bey de schloß Ulmen / und ein ander bey dem Closter züm Laich / die seind sere tieff / habe kein ynflüß aber vil außflüß / die nennet man Marh unnd seind fischreich."'' (Also two noteworthy lakes are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maar USGS
A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow crater lake which may also be called a maar. The name comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany. Notes: * According to German Wikipedia's ''"Maar"'' article, in 1544 in his book ''Cosmographia'', Sebastian Münster (1488–1552) first applied the word "maar" (as ''Marh'') to the Ulmener Maar and the Laacher See. See: Sebastian Münster, ''Cosmographia'' (Basel, Switzerland: Heinrich Petri, 1544)p. 341. From p. 341: ''"Item zwen namhafftiger seen seind in der Eyfel / einer bey de schloß Ulmen / und ein ander bey dem Closter züm Laich / die seind sere tieff / habe kein ynflüß aber vil außflüß / die nennet man Marh unnd seind fischreich."'' (Also two noteworthy lakes are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phreatomagmatic Eruption
Phreatomagmatic eruptions are volcanic eruptions resulting from interaction between magma and water. They differ from exclusively magmatic eruptions and phreatic eruptions. Unlike phreatic eruptions, the products of phreatomagmatic eruptions contain juvenile (magmatic) clasts.Heiken, G. & Wohletz, K. 1985. Volcanic Ash. University of California Press, Berkeley It is common for a large explosive eruption to have magmatic and phreatomagmatic components. Mechanisms Several competing theories exist as to the exact mechanism of ash formation. The most common is the theory of explosive thermal contraction of particles under rapid cooling from contact with water. In many cases the water is supplied by the sea, for example with Surtsey. In other cases the water may be present in a lake or caldera-lake, for example Santorini, where the phreatomagmatic component of the Minoan eruption was a result of both a lake and later the sea. There have also been examples of interaction between magma a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devil Mountain Lakes
Devil Mountain Lakes ( Inupiaq: ''Qitiqłiik'') is a maar (a form of crater lake) in the western part of Alaska. The lake is considered to be the largest maar in the world , Alaska Science Forum and is part of the Espenberg volcanic field, Espenberg volcanic field. Geography Devil Mountain Lakes are located about southwest of on the northern part of the .[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eckfelder Maar
The Eckfelder Maar is a former volcanic lake, that was formed during the Middle Eocene around 44.3 million years ago and is thus the oldest known maar. It lies in the southwestern Eifel mountains near Manderscheid in Germany.''Das Eckfelder Maar'' at www.eckfelder-maar.de. Retrieved 22 Jul 2016. It is also an important site that contains numerous fossil remains of fauna and flora, some of them nearly complete state of preservation. It has been continuously scientifically researched since 1987. The large number of finds - to date 25,000 fossil specimens have been found - have enabled a very detailed reconstruction of the landscape. This maar, a low vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eichholzmaar
The Eichholzmaar is one of the smaller maars in the Volcanic Eifel and lies on the ''Landstraße'' between Steffeln and Duppach. It has a diameter of c. 120 metres. Its greatest depth is 3 metres. The circular shape of the bowl of the maar can still be easily seen. It lies exactly on a geological fault line, which runs from northwest to southeast. At the beginning of the 20th century the maar was drained in order to create meadows. From late summer 2007 to spring 2008 a renaturalisation was carried out and the lake restored with an area of c. 1,1 hectares. In only a few years the maar has become a refuge for rare water birds and reptiles. Two natural mineral springs in the immediate vicinity of the maar are accessible on foot. About 300 metres upstream in a westerly direction from the Eichholzmaar is the mineral spring known as the ''Steffelner Dress'' (). Around 270 metres downstream in an easterly direction from the Eichholzmaar is the mineral spring of ''Aueler Dress'' (). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daun (Germany)
Daun is a town in the Vulkaneifel district in Rhineland-Palatinate, Germany. It is the district seat and also the seat of the ' of Daun. Geography Location The town lies in the , a part of the Eifel known for its volcanic history, geographical and geological features, and even ongoing activity today, including gases that sometimes well up from the earth. Daun lies south of the High Eifel on the river Lieser. Found from 2.5 to 3.5 km southeast of Daun’s town centre are the Dauner ''Maare'', a group of three volcanic lakes separated almost wholly by only the walls of tuff between them. The town is home to the '. Daun is furthermore a spa town and has mineral water springs. Constituent communities The district seat of Daun has 8,514 inhabitants (as of 31 December 2005, counting only those with their main residence in the town). Besides the main town, also called Daun (4,264 inhabitants), the municipal area also includes these outlying centres (') that were formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Crater Lake
A volcanic crater lake is a lake in a crater that was formed by explosive activity or a collapse during a volcanic eruption. Formation Lakes in calderas fill large craters formed by the collapse of a volcano during an eruption. Lakes in maars fill medium-sized craters where an eruption deposited debris around a vent. Crater lakes form as the created depression, within the crater rim, is filled by water. The water may come from precipitation, groundwater circulation (often hydrothermal fluids in the case of volcanic craters) or melted ice. Its level rises until an equilibrium is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation, subsurface seepage, and, in places, surface leakage or overflow when the lake level reaches the lowest point on its rim. At such a saddle location, the upper portion of the lake is contained only by its adjacent natural volcanic dam; continued leakage through or surface outflow ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seward Peninsula
The Seward Peninsula is a large peninsula on the western coast of the U.S. state of Alaska whose westernmost point is Cape Prince of Wales. The peninsula projects about into the Bering Sea between Norton Sound, the Bering Strait, the Chukchi Sea, and Kotzebue Sound, just below the Arctic Circle. The entire peninsula is about long and wide. Like Seward, Alaska, it was named after William H. Seward, the United States Secretary of State who fought for the U.S. purchase of Alaska. The Seward Peninsula is a remnant of the Bering land bridge, a roughly thousand mile wide swath of land connecting Siberia with mainland Alaska during the Pleistocene Ice Age. This land bridge aided in the migration of humans, as well as plant and animal species, from Asia to North America. Excavations at sites such as the Trail Creek Caves and Cape Espenberg in the Bering Land Bridge National Preserve as well as Cape Denbigh to the south have provided insight into the timeline of prehistorical migrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permafrost
Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface is underlain by permafrost, with the total area of around 18 million km2. This includes substantial areas of Alaska, Greenland, Canada and Siberia. It can also be located on mountaintops in the Southern Hemisphere and beneath ice-free areas in the Antarctic. Permafrost does not have to be the first layer that is on the ground. It can be from an inch to several miles deep under the Earth's surface. It frequently occurs in ground ice, but it can also be present in non-porous bedrock. Permafrost is formed from ice holding various types of soil, sand, and rock in combination. Permafrost contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide, making tundra soil a carbon sink. As global war ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Espenberg
Cape Espenberg is a cape located on the Seward Peninsula in Alaska, on the Chukchi Sea coast. Cape Espenberg points northwards, 42 mi NW of Deering, Kotzebue-Kobuk Low. On its southeastern side there is the small Goodhope Bay, an inlet of the Kotzebue Sound. Named in 1816 by Lt. Otto von Kotzebue (1821, p. 236) for Dr. Karl Espenberg, a surgeon who accompanied Captain (later Admiral, IRN) Adam Johann von Krusenstern Adam Johann von Krusenstern (also Krusenstjerna in Swedish; russian: Ива́н Фёдорович Крузенште́рн, tr. ; 10 October 177012 August 1846) was a Russian admiral and explorer, who led the first Russian circumnavigatio ... on his voyage around the world in 1803–06. Cape Espenberg lies on the Arctic Circle at the terminus of a 30 km long mainland attached beach ridge plain at the northern limit of Seward Peninsula, in western Alaska. At the entry of the shallow Kotzebue Sound embayment, Cape Espenberg faces a potentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steffeln
Steffeln is an ''Ortsgemeinde'' – a municipality belonging to a ''Verbandsgemeinde'', a kind of collective municipality – in the Vulkaneifel district in Rhineland-Palatinate, Germany. It belongs to the ''Verbandsgemeinde'' of Gerolstein, whose seat is in the municipality of Gerolstein. Geography Location The municipality lies in the Vulkaneifel, a part of the Eifel known for its volcanic history, geographical and geological features, and even ongoing activity today, including gases that sometimes well up from the earth. Constituent communities Steffeln's ''Ortsteile'' are, besides the main centre, also called Steffeln, Auel and Lehnerath. Climate Yearly precipitation in Steffeln amounts to 946 mm, which is very high, falling into the highest fourth of the precipitation chart for all Germany. At 81% of the German Weather Service's weather stations, lower figures are recorded. The driest month is April. The most rainfall comes in December. In that month, precipit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Rock
Volcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks. For these reasons, in geology, volcanics and shallow hypabyssal rocks are not always treated as distinct. In the context of Precambrian shield geology, the term "volcanic" is often applied to what are strictly metavolcanic rocks. Volcanic rocks and sediment that form from magma erupted into the air are called "volcaniclastics," and these are technically sedimentary rocks. Volcanic rocks are among the most common rock types on Earth's surface, particularly in the oceans. On land, they are very common at plate boundaries and in flood basalt provinces. It has been estimated t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
