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Raymond Effect
Raymond Effect is a flow effect in ice sheets, occurring at flow divides, which gives rise to disturbances in the stratigraphy, showing unusual arches or anticlines called ''Raymond Arches''. The stratigraphy is detected by radio-echo sounding. The Raymond effect arises from the unusual flow properties of ice, as its viscosity decreases with stress. It is of importance because it provides field evidence for the flow properties of ice. In addition, it permits dating of changes in ice flow and the establishment of changes in ice thickness. The effect was first predicted by Charles F. Raymond. Raymond Arches and the Raymond Effect have been observed at numerous other ice divides e.g. Siple Dome, Fletcher Ice Rise, Berkner Island, Roosevelt Island, Korff Ice Rise. Ice viscosity is stress Stress may refer to: Science and medicine * Stress (biology), an organism's response to a stressor such as an environmental condition * Stress (linguistics), relative emphasis or prominence giv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Sheets
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Last Glacial Maximum, the Laurentide Ice Sheet covered much of North America, the Weichselian ice sheet covered Northern Europe and the Patagonian Ice Sheet covered southern South America. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery. Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams. The present-day polar ice sheets are relatively young in ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siple Dome
Siple Dome () is an ice dome approximately 100 km wide and 100 km long, located 130 km east of Siple Coast in Antarctica. Charles Bentley and Robert Thomas established a "strain rosette" on this feature to determine ice movement in 1973–74. They referred to the feature as Siple Dome because of its proximity to Siple Coast. Siple Dome ice core The Siple Dome ice core project (79.468° S 112.086° W) was conducted by the United States National Science Foundation. The deepest ice was recovered in 1999 from 974 m, with an age of 97,600 years. It is best known for the poorly-explained steps in water isotopes during the deglacial, which are unique to this core and may indicate a rapid decrease in the surface elevation of the adjoining ice streams during the deglacial and a record of atmospheric carbon dioxide. The Chief Scientist was Kendrick Taylor. Radar surveys of internal ice structure In the 1990s a team from the University of Washington and St Olaf College su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the internal frictional force between adjacent layers of fluid that are in relative motion. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls. Experiments show that some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. For a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity. In general, viscosity depends on a fluid's state, such as its temperature, pressure, and rate of deformation. However, the dependence on some of these properties is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Korff Ice Rise
Korff Ice Rise is an ice rise, long and wide, lying east-northeast of Skytrain Ice Rise in the southwestern part of the Ronne Ice Shelf, Antarctica. It was discovered by the US–IGY Ellsworth Traverse Party, 1957–58, and named by the party for Professor Serge A. Korff, vice chairman of the cosmic ray technical panel, U.S. National Committee for the International Geophysical Year, 1957–59. Radar surveying in 2013-2015 by a team from the British Antarctic Survey found the ice to be up to around thick and found evidence that the Raymond Effect was operating beneath the ice divide An ice divide is the boundary on an ice sheet, ice cap or glacier separating opposing flow directions of ice, analogous to a water divide. Ice divides are important for geochronological investigations that use ice cores, since such coring is typ .... References Filchner-Ronne Ice Shelf Ice rises of Queen Elizabeth Land {{QueenElizabethLand-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roosevelt Island, Antarctica
Roosevelt Island is the second largest ice rise of Antarctica and world-wide, after Berkner Island. Despite its name, it is not an island, since the bedrock below the ice at its highest part is below sea level. It is about long in a NW-SE direction, wide and about in area, lying under the eastern part of the Ross Ice Shelf of Antarctica. Its central ridge rises to about above sea level, but this and all other elevations of the ice rise are completely covered by ice, so that it is invisible at ground level. Examination of how the ice flows above it establishes the existence and extent of the ice rise. Radar surveying carried out between 1995 and 2013 showed that the Raymond Effect was operating beneath the ice divide. The ice rise has become a focus of the Roosevelt Island Climate Evolution (RICE) research using ice coring. Rear Admiral Richard E. Byrd named it in 1934 after US President Franklin D. Roosevelt. Byrd was the leader of the expedition that discovered the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Geophysical Research
The ''Journal of Geophysical Research'' is a peer-reviewed scientific journal. It is the flagship journal of the American Geophysical Union. It contains original research on the physical, chemical, and biological processes that contribute to the understanding of the Earth, Sun, and Solar System. It has seven sections: A (Space Physics), B (Solid Earth), C (Oceans), D (Atmospheres), E (Planets), F (Earth Surface), and G (Biogeosciences). All current and back issues are available online for subscribers. History The journal was originally founded under the name ''Terrestrial Magnetism'' by the American Geophysical Union's president Louis Agricola Bauer in 1896. It was renamed to ''Terrestrial Magnetism and Atmospheric Electricity'' in 1899 and in 1948 it acquired its current name. In 1980, three specialized sections were established: ''A: Space Physics'', ''B: Solid Earth'', and ''C: Oceans''. Subsequently, further sections have been added: ''D: Atmospheres'' in 1984, ''E: Planets'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berkner Island
Berkner Island (also known as the Berkner Ice Rise or as Hubley Island) is an Antarctic ice rise, where bedrock below sea level has caused the surrounding ice sheet to create a dome. If the ice cap were removed, the island would be underwater. Berkner Island is completely ice-covered and is about long and wide, with an area of . It is surrounded by the Filchner-Ronne Ice Shelf. The northernmost point of the Berkner is about from the open sea. It lies in the overlapping portion of the Argentine and the British Antarctic territorial claims. The island rises to ( according to other sources) and separates the Ronne Ice Shelf from the Filchner Ice Shelf. It is characterized by two domes, ''Reinwarthhöhe'' in the north (), and ''Thyssenhöhe'' in the south (). It is indented by three bays on the eastern side, which are, from north to south, the McCarthy Inlet, the Roberts Inlet, and the Spilhaus Inlet. The southern tip is named the Mulvaney Promontory. Gould Bay is on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fletcher Ice Rise
Fletcher Ice Rise (), or Fletcher Promontory, is a large ice rise, long and wide, at the southwest side of the Ronne Ice Shelf, Antarctica. The feature is completely ice covered and rises between Rutford Ice Stream and Carlson Inlet. The ice rise was observed, photographed and roughly sketched by Lieutenant Ronald F. Carlson, U.S. Navy, in the course of a C-130 aircraft flight of December 14–15, 1961 from McMurdo Sound to this vicinity and returning. It was mapped in detail by the U.S. Geological Survey from Landsat imagery taken 1973–74, and was named by the Advisory Committee on Antarctic Names for Joseph O. Fletcher, director of the Office of Polar Programs, National Science Foundation, 1971–74. Between 2005 and 2007 extensive ground-based and airborne radar surveys by teams from the British Antarctic Survey (BAS) were carried out, which obtained information about the thickness and internal structure of the ice mass, confirming operation of the Raymond Effect at the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Glaciology (journal)
The International Glaciological Society (IGS) was founded in 1936 to provide a focus for individuals interested in glaciology, practical and scientific aspects of snow and ice. It was originally known as the "Association for the Study of Snow and Ice". The name was changed to the "British Glaciological Society" in 1945. With more and more non-British glaciologists attending its readings and submitting papers for publication, the name was changed to the "Glaciological Society" in 1962 and finally the Society acquired its present name in 1971. The IGS publishes the ''Journal of Glaciology'', ''Annals of Glaciology'' and ''ICE'', the news bulletin of the IGS; the ''Journal of Glaciology'' won the ALPSP/Charlesworth Award for the "Best Learned Journal of 2007". Branches The Society has branches in different parts of the world, providing a further opportunity for those sharing a common interest to meet and exchange information: * British Branch (United Kingdom) * Nordic branch * N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Divide
An ice divide is the boundary on an ice sheet, ice cap or glacier separating opposing flow directions of ice, analogous to a water divide. Ice divides are important for geochronological investigations that use ice cores, since such coring is typically made at highest point of an ice sheet dome to avoid disturbances arising from horizontal ice movement. Ice divides are used for looking at how the atmosphere varied over time. Coring at dome peaks increases precision of reconstructions as it is the place where horizontal motion is at its least. The Raymond Effect operates at ice divides, creating anticlines in the radar-detected isochrones, allowing greater capture of older ice when coring. Analysis of ice cores relies on the downward motion of ice, trapping changes of atmospheric gases through time into its layers. Scientist locate ice divides and take ice cores from them, which are typically long cylindrical poles of ice, and analyse them to find chemical elements that the snow an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geophysical Research Letters
''Geophysical Research Letters'' is a biweekly peer-reviewed scientific journal of geoscience published by the American Geophysical Union that was established in 1974. The editor-in-chief is Harihar Rajaram. Aims and scope The journal aims for rapid publication of concise research reports on one or more of the disciplines covered by the American Geophysical Union, such as atmospheric sciences, solid Earth, space science, oceanography, hydrology, land surface processes, and the cryosphere. The journal also publishes invited reviews that cover advances achieved during the past two or three years. The target readership is the earth science community, the broader scientific community, and the general public. Abstracting and indexing This journal is abstracted and indexed in: According to the 2020 ''Journal Citation Reports'', the journal has a 2019 impact factor of 4.58. ''Geophysical Research Letters'' was also the 5th most cited publication on climate change between 1999 and 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
