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Karikkoselkä
Karikkoselkä is a lake formed in an impact crater in Petäjävesi, Finland. Karikkoselkä is located approximately 30 km east from the centre of Keurusselkä, a much older and larger impact crater. Most lakes in the region are elongated in northwest–southeast direction due to glaciation, but Karikkoselkä is strikingly round. Many shatter cones, rock formations that form under the extreme pressures of impact, have been found around the lake. Further evidence comes from aeromagnetic maps, which show a clear magnetic anomaly in the impact crater area. In addition, samples collected from deep drillings into the lake bottom confirm the impact origin of the structure. The crater is the smallest identified in Finland, 1.4 km diameter and 150 m deep. Due to sediments the lake has a maximum depth of 26m which is unusually deep for a lake in the region. Karikkoselkä is estimated to be between 230 Ma and 450 Ma (million years old), most likely near 240 Ma (Triassic or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters In Finland
As of June 2018, 12 confirmed impact craters have been found in Finland. They are listed below, sorted by original diameter. Note 1: The "original" crater dimensions are coarse estimates. Original depths were calculated using the given original diameter using thImpact: Earth!program. Note 2: "Current solid surface" topography is calculated from the deepest floor (regardless whether it is underwater or on dry land) to highest rim crest; other depth values give the depth of the floor in relation to the original terrain, thus excluding the rim and/or central uplift. Note 3: Evidence for impact origin for a given structure is often provided in several publications. The year column includes some publications where some evidence of impact origin was provided even though an impact was not necessarily suggested by the authors; somewhere an impact was suggested even though the proof wasn't conclusive; and somewhere definite proof was provided. General note 1: Crater sizes and shapes vary a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petäjävesi
Petäjävesi (; lit. "pine water") is a municipalities of Finland, municipality of Finland. It is located in the provinces of Finland, province of Western Finland, next to the city of Jyväskylä, and is part of the Central Finland regions of Finland, region. The municipality has a population of () and covers an area of of which is water. The population density is . Neighbouring municipalities are Jyväskylä, Jämsä, Keuruu, Multia and Uurainen. The municipality is unilingually Finnish language, Finnish. The Petäjävesi Old Church, was listed as a UNESCO World Heritage Site in 1994 for its testimony to Nordic church architecture. Nature There are all together 99 lakes in Petäjävesi. The biggest lakes are Jämsänvesi-Petäjävesi, Ala-Kintaus and Ylä-Kintaus. Karikkoselkä is a lake in Petäjävesi, which is formed by a meteorite. The Karikkoselkä impact crater is located southeast of the municipal centre. Notable people *Mika Aaltola (1969–) *Jarmo Kytölehto (1961 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keurusselkä
Keurusselkä is a lake in Central Finland between the towns of Keuruu to the north and Mänttä to the south. It covers an area of . Its average depth is with a maximum depth of . The surface lies at above sea level. The lake is long and is a part of the Kokemäenjoki water system. Keurusselkä gained international publicity in 2004 when a pair of amateur geologists discovered an ancient impact crater on the western shore of the lake. Environmental issues In 1986, the Keurusselkä region was heavily contaminated (70 kBq/m2) by radioactive caesium, , from the Chernobyl disaster fallout. In 2003, some fish near Mänttä still had caesium concentrations several times higher than in Olkiluoto and Loviisa, which host the nuclear plants of Finland. This is due to the difference between the uptake of caesium in fresh water and brackish or saline water. However, the concentration levels are so small that eating the fish is not considered a health risk. Apart from radioactivity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater Lake
An impact crater lake is a lake inside a depression caused by the impact of a meteor. It is also known as an annular lake in cases where the water body is shaped like a ring, as many impact crater lakes are. Examples One of the largest impact crater lakes is Manicouagan Reservoir, Lake Manicouagan in Canada; the crater is a multiple-ring structure about across, with its diameter inner ring its most prominent feature; it contains a diameter annular lake, surrounding an inner island plateau, René-Levasseur Island. It is Earth's sixth-largest confirmed impact crater according to rim-to-rim diameter. List See also * Volcanic crater lake References Impact crater lakes, {{Geo-term-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landsat 7
Landsat 7 is the seventh satellite of the Landsat program. Launched on 15 April 1999, Landsat 7's primary goal is to refresh the global archive of satellite photos, providing up-to-date and cloud-free images. The Landsat program is managed and operated by the United States Geological Survey, and data from Landsat 7 is collected and distributed by the USGS. The NASA WorldWind project allows 3D images from Landsat 7 and other sources to be freely navigated and viewed from any angle. The satellite's companion, Earth Observing-1, trailed by one minute and followed the same orbital characteristics, but in 2011 its fuel was depleted and EO-1's orbit began to degrade. Landsat 7 was built by Lockheed Martin Space Systems. In 2016, NASA announced plans to attempt the first ever refueling of a live satellite by refueling Landsat 7 in 2020 with the OSAM-1 mission; as of 2021, the launch date has slipped to 2025. NASA plans to decommission the satellite following the 2021 launch and activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Misquotation
A quotation is the repetition of a sentence, phrase, or passage from speech or text that someone has said or written. In oral speech, it is the representation of an utterance (i.e. of something that a speaker actually said) that is introduced by a quotative marker, such as a verb of saying. For example: John said: "I saw Mary today". Quotations in oral speech are also signaled by special prosody in addition to quotative markers. In written text, quotations are signaled by quotation marks. Quotations are also used to present well-known statement parts that are explicitly attributed by citation to their original source; such statements are marked with ( punctuated with) quotation marks. Quotations are often used as a literary device to represent someone's point of view. They are also widely used in spoken language when an interlocutor wishes to present a proposition that they have come to know via hearsay. As a literary device A quotation can also refer to the repeated use of unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic Impact Craters
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Anomalies
In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material. The magnetic variation (geomagnetic reversals) in successive bands of ocean floor parallel with mid-ocean ridges was important evidence for seafloor spreading, a concept central to the theory of plate tectonics. Measurement Magnetic anomalies are generally a small fraction of the magnetic field. The total field ranges from 25,000 to 65,000 nanoteslas (nT). To measure anomalies, magnetometers need a sensitivity of 10 nT or less. There are three main types of magnetometer used to measure magnetic anomalies: # The fluxgate magnetometer was developed during World War II to detect submarines. It measures the component along a particular axis of the sensor, so it needs to be oriented. On land, it is often oriented vertically, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kymi Basin
Kymi may refer to: *Kymi, Greece, a town in Euboea, Greece *Kymi, Finland, a former municipality in Finland *Kymi (constituency), a constituency in the Finnish Parliament *Kymi (region), or ''Kymenlaakso'', the region of Finland * Kymi B.C., a basketball club based in Kymi, Greece *Kymi Ring, a racing circuit in Finland *Kymi River, a river in Finland * Kymi Province, a province in Finland from 1947 to 1997 *KYMI (FM), a radio station (97.5 FM) licensed to serve Charlo, Montana, United States *KJJT, a defunct radio station (98.5 FM) formerly licensed to serve Los Ybanez, Texas, United States, which held the call sign KYMI from 1990 to 2007 See also *Kyminlinna Kyminlinna (literally, 'the castle of Kymi') is a fortress located in the northern part of island of Hovinsaari in Kotka, on the south coast of Finland. Kyminlinna is part of the South-Eastern Finland fortification system built by Russia afte ..., a castle in Finland * Kyme (other) {{Disambiguation, geo, ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of Finland
Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *''Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from ''Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a student magazine for the University of Nottingham, England * ''Bathi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neolithic
The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of settlement. It began about 12,000 years ago when farming appeared in the Epipalaeolithic Near East, and later in other parts of the world. The Neolithic lasted in the Near East until the transitional period of the Chalcolithic (Copper Age) from about 6,500 years ago (4500 BC), marked by the development of metallurgy, leading up to the Bronze Age and Iron Age. In other places the Neolithic followed the Mesolithic (Middle Stone Age) and then lasted until later. In Ancient Egypt, the Neolithic lasted until the Protodynastic period, 3150 BC.Karin Sowada and Peter Grave. Egypt in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoproterozoic
The Paleoproterozoic Era (;, also spelled Palaeoproterozoic), spanning the time period from (2.5–1.6 Ga), is the first of the three sub-divisions (eras) of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's geological history. It was during this era that the continents first stabilized. Paleontological evidence suggests that the Earth's rotational rate ~1.8 billion years ago equated to 20-hour days, implying a total of ~450 days per year. Atmosphere Before the enormous increase in atmospheric oxygen, almost all existing lifeforms were anaerobic organisms whose metabolism was based on a form of cellular respiration that did not require oxygen. Free oxygen in large amounts is toxic to most anaerobic organisms. Consequently, most died when the atmospheric free oxygen levels soared in an extinction event called the Great Oxidation Event, which brought atmospheric oxygen levels to up to 10% of their current level. The only creatures that survi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
