| 释义 |
glacier
glaciera mass of slowly moving land ice formed by the accumulation of snow on high ground
Not to be confused with:glazier – a person who fits windows with glass or panes of glassgla·cier G0137800 (glā′shər)n. A huge mass of ice slowly flowing over a landmass, formed from compacted snow in an area where snow accumulation has exceeded melting and sublimation.
[French, from Old French, cold place, from glace, ice, from Vulgar Latin *glacia, from Latin glaciēs; see gel- in Indo-European roots.]
gla′ciered adj.glacier (ˈɡlæsɪə; ˈɡleɪs-) n (Physical Geography) a slowly moving mass of ice originating from an accumulation of snow. It can either spread out from a central mass (continental glacier) or descend from a high valley (alpine glacier)[C18: from French (Savoy dialect), from Old French glace ice, from Late Latin glacia, from Latin glaciēs ice]gla•cier (ˈgleɪ ʃər)
n. an extended mass of ice formed from snow falling and accumulating over the years and moving very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of accumulation, as in continental glaciers. [1735–45; < dial. French, derivative of Old French glace ice < Vulgar Latin *glacia] gla′ciered, adj. gla·cier (glā′shər) A large mass of ice flowing very slowly through a valley or spreading outward from a center. Glaciers form over many years from packed snow in areas where snow accumulates faster than it melts. A glacier is always moving, but when its forward edge melts faster than the ice behind it advances, the glacier as a whole shrinks backward.glacierA mass of ice that creeps down a valley, scouring its floor and sides.Thesaurus| Noun | 1. |  glacier - a slowly moving mass of ice Alpine glacier, Alpine type of glacier - a glacier that moves down from a high valleycontinental glacier - a glacier that spreads out from a central mass of iceicefall - a steep part of a glacier resembling a frozen waterfallice mass - a large mass of icemoraine - accumulated earth and stones deposited by a glacierneve - the upper part of a glacier (beyond the limit of perpetual snow) where the snow turns to icePiedmont glacier, Piedmont type of glacier - a type of glaciation characteristic of Alaska; large valley glaciers meet to form an almost stagnant sheet of iceice, water ice - water frozen in the solid state; "Americans like ice in their drinks" |
Translationsglacier (ˈglӕsiə) , ((American) ˈgleiʃər) noun a mass of ice, formed from the snow on mountains. 冰河 冰川glacier
glacier, moving mass of ice that survives year to year, formed by the compacting of snow into névé and then into granular ice and set in motion outward and downward by the force of gravity and the stress of its accumulated mass. Glaciers are usually found in high altitudes and latitudes. Classification Glaciers are of four chief types. Valley, or mountain, glaciers are tongues of moving ice sent out by mountain snowfields following valleys originally formed by streams. In the Alps there are more than 1,200 valley glaciers. Piedmont glaciers, which occur only in high latitudes, are formed by the spreading of valley glaciers where they emerge from their valleys or by the confluence of several valley glaciers. Small ice sheets known as ice caps are flattened, somewhat dome-shaped glaciers spreading out horizontally in all directions and cover mountains and valleys. Continental glaciers are huge ice sheets whose margins may break off to form icebergs (see icebergiceberg,
mass of ice that has become detached, or calved, from the edge of an ice sheet or glacier and is floating on the ocean. Because ice is slightly less dense than water about one ninth of the total mass of a berg projects above the water.
..... Click the link for more information. ). The only existing continental glaciers are the ice sheets of Greenland and Antarctica, but during glacial periodsglacial periods,
times during which large portions of the earth's surface were covered with thick glacial ice sheets. In the Pleistocene epoch, in the Carboniferous and Permian periods of the Paleozoic era era, and in Huronian time of the Precambrian, the earth experienced an
..... Click the link for more information. they were far more widespread. Glaciers may be classified as warm or cold depending on whether their temperatures are above or below −10°C; (14°F;). Geological Impact Glaciers alter topography, and their work includes erosionerosion
, general term for the processes by which the surface of the earth is constantly being worn away. The principal agents are gravity, running water, near-shore waves, ice (mostly glaciers), and wind.
..... Click the link for more information. , transportation, and deposition. Mountain glaciers carve out amphitheaterlike vertical-walled valley heads, or cirques, at their sources. They transform V-shaped valleys into U-shaped valleys by grinding away the projecting bases of slopes and cliffs and leveling the floors of the valleys; in this process tributary valleys are frequently left "hanging," with their outlets high above the new valley floor. When the tributary valleys contain streams, waterfallswaterfall,
a sudden unsupported drop in a stream. It is formed when the stream course is interrupted as when a stream passes over a layer of harder rock—often igneous—to an area of softer and therefore more easily eroded rock; the edge of a cliff or plateau; or the
..... Click the link for more information. and cascades are formed, such as Bridal Veil Falls of Yosemite National Park. Elevations over which glaciers pass usually are left with gently sloping sides in the direction from which the glacier approached (stoss sides) and rougher lee sides. Humps and bosses of rock so shaped are known as roches moutonnées. The debris from glacial erosion is carried upon, within, and underneath the ice. The debris frozen into the underside of the glacier acts as a further erosive agent, polishing the underlying rock and leaving scratches, or striae, running in the direction of the movement of the glacier. Glacial deposits are often known as till or driftdrift,
deposit of mixed clay, gravel, sand, and boulders transported and laid down by glaciers. Stratified, or glaciofluvial, drift is carried by waters flowing from the melting ice of a glacier.
..... Click the link for more information. . The melting of the ice in summer forms glacial streams flowing under the ice, while the retreat of a large glacier sometimes leaves a temporary glacial lake, such as the ice age Lake AgassizAgassiz, Lake
, glacial lake of the Pleistocene epoch, c.700 mi (1,130 km) long, 250 mi (400 km) wide, formed by the melting of the continental ice sheet beginning some 14,000 years ago; it eventually covered much of present-day NW Minnesota, NE North Dakota, S Manitoba, central
..... Click the link for more information. . Fjordsfjord
or fiord
, steep-sided inlet of the sea characteristic of glaciated regions. Fjords probably resulted from the scouring by glaciers of valleys formed by any of several processes, including faulting and erosion by running water.
..... Click the link for more information. generally owe their origin to glaciers. Glacial Movement A glacier moves as a solid rather than as a liquid, as is indicated by the formation of crevasses (see crevassecrevasse
, large crack in the upper surface of a glacier, formed by tension acting upon the brittle ice. Transverse crevasses occur where the grade of the glacier bed becomes suddenly steeper; longitudinal crevasses, where the glacier spreads over a wider valley or plain.
..... Click the link for more information. ). The center of a glacier moves more rapidly than the sides and the surface more rapidly than the bottom, because the sides and bottom are held back by friction. The rate of flow depends largely on the volume of ice in movement, the slope of the ground over which it is moving, the slope of the upper surface of the ice, the amount of water the ice contains, the amount of debris it carries, the temperature, and the friction it encounters. Glaciers are always in movement, but the extent of the apparent movement depends on the rate of advance and the rate of melting. If the ice melts at its edge faster than it moves forward, the edge of the glacier retreats; if it moves more rapidly than it melts, the edge advances; it is stationary only if the rate of movement and the rate of melting are the same. The causes of glacial movement are exceedingly complex and doubtless are not all operative on the same glacier at the same time. Important elements in glacial movement are melting under pressure followed by refreezing, which may push the mass in the direction of least resistance; sliding or shearing of layers of ice one on top of the other; and rearrangement of the granules when pressure causes melting. Sudden, rapid movements of glaciers, called glacier surges, have been observed in Alaskan and other glaciers, with evidence for such abnormal movements as the crumpled lines of surface debris found on them. It is thought that the relatively sudden movement and melting of glaciers may be indicative of climateclimate,
average condition of the atmosphere near the earth's surface over a long period of time, taking into account temperature, precipitation (see rain), humidity, wind, barometric pressure, and other phenomena.
..... Click the link for more information. warming. glacier[′glā·shər] (hydrology) A mass of land ice, formed by the further recrystallization of firn, flowing slowly (at present or in the past) from an accumulation area to an area of ablation. glacier a slowly moving mass of ice originating from an accumulation of snow. It can either spread out from a central mass (continental glacier) or descend from a high valley (alpine glacier) MedicalSeeglacialglacier
Related to glacier: Siachen GlacierWords related to glaciernoun a slowly moving mass of iceRelated Words- Alpine glacier
- Alpine type of glacier
- continental glacier
- icefall
- ice mass
- moraine
- neve
- Piedmont glacier
- Piedmont type of glacier
- ice
- water ice
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