What is the difrence between a contiental glacier and valley glaciers?
93319
Bairdt found a good website for the information, but Id like to point out that the North Pole does NOT have a glacier--the North Pole is covered by the Arctic Ocean--the surface of which is frozen as sea ice (not glacial ice).  I think sea ice can be as much as 10 feet thick, though.  Antarctica (around the South Pole) contains two continental ice sheets--the West Antarctic Ice Sheet (WAIS) and the East Antarctic Ice Sheet (EAIS).\n\nContinental glaciers are defined by their size (they cover very large areas of land and/or shallow ocean floor) and by their flow characteristics.  Since they are so large, they may have several different areas of accumulation, but generally flow in a radial pattern--similar to how pancake batter flows radially when you plop a spoonful onto a griddle.\n\nA valley glacier (or alpine glacier) is restricted to a valley.  They generally form at high altitudes near the divides in mountain ranges.  The initial valley they start in is called a cirque.  A small glacier occupying a cirque is called a cirque glacier (see #1 below--theres a bunch of little glaciers sitting in cirques).  When enough snow falls over a period of years, the glacier grows and flows down mountain valleys.  It then becomes a valley glacier.  #2 below is a great photo of a valley glacier--it looks like a river.  A valley glacier can ultimately flow out of its valley onto a piedmont and spread out.\n\nAs Bairdt pointed out, valley glaciers erode the walls of the valley they occupy.  The glaciers flow characteristics cause the valley to look u-shaped if you look at it in cross-section (check out #3 below!  That is as perfect a u-shaped valley as you will ever see).  Stream valleys are typically v-shaped.\n\nCheck out #4--a continental ice sheet.  Note that as far as you can see is ice.
5986
of course they move very slowly\nso slowly that it is not noticeable\n\nSpeed of glacial movement\nThe speed of glacial displacement is partly determined by friction. Friction makes the ice at the bottom of the glacier move slower than the upper portion. In alpine glaciers, friction is also generated at the valley's side walls, which slows the edges relative to the center. This has been confirmed by experiments in the 19th century, in which stakes were planted in a line across an alpine glacier, and as time passed, those in the center moved further.\n\nMean speeds vary; some have speeds so slow that trees can establish themselves among the deposited scourings. In other cases they can move as fast as many meters per day, as is the case of Byrd Glacier, an overflowing glacier in Antarctica which moves 750-800 meters per year (some 2 meters (6 ft) per day), according to studies using satellites.\n\nMany glaciers have periods of very rapid advancement called surges.[2] These glaciers exhibit normal movement until suddenly they accelerate, then return to their previous state. During these surges, the glacier may reach velocities up to 1000 times greater than normal.
75602
The Valles Marineris is a system of canyons located just south of the Martian equator. The system is about 4000 km long, and, if on earth, would extend all the way across the United States. The central individual troughs, generally 50 to 100 km wide, merge into a depression as much as 600 km wide. In places the canyon floor reaches a depth of 10 km, 6 to 7 times deeper than the Grand Canyon. The geologic history of the central canyon system is complex: first the surface collapsed into a few deep depressions that later became filled with layered material, perhaps as lake deposits. Then graben-forming faults cut across some of the older troughs thus widening existing troughs, breaching barriers between troughs, and forming additional ones. At that time the interior deposits were locally bent and tilted, and perhaps water, if still present, spilled out and flowed toward the outflow channels. Huge landslides fell into the voids created by the new grabens. Wind-drifted material, mostly dark in color, apparently still moves along the canyon floor and locally forms conspicuous dunes. We have created images of the martian canyon, primarily in the central region, Ophir and Candor Chasmata, by merging Viking images with topographic maps. Maps of Ophir and central Candor Chasmata are derived from stereo images by photogrammetry. They have 200-m contour interval, except for local gaps that have 1-km contour interval. West Candor Chasma has 1-km contour interval. The three-dimensional anaglyph images generated using locally produced MIPS software (Mini Image Processing System) require red and blue glasses to view. A Geographic Information System (GIS) software package (ArcInfo) was used to super-impose several layers of information, specifically geologic units, geologic structures, images, and topography.
768143
A tributary (or confluent/affluent) is a stream or river which flows into another river (a parent river) or body of water but which may not flow directly into the sea. In orography, tributaries are ordered from those nearest to the source of the river to those nearest to the mouth of the river. A confluence is where two or more tributaries or rivers flow together.\n\nThe descriptive terms right tributary and left tributary always apply from the perspective of looking downstream (in the direction the current is going), similarly to the river banks.\n\nThe opposite of a tributary is a distributary; a river branch that flows away from the main stream. A river and all its tributaries drain the watershed of the river
448741
Either a valley (both sides going down to a common 'low point' of the V) or a ridge (both side going up to a common "high point" of the V) depending on which way the V runs in relation to the topo lines.
669828
the difference is big.\nBasicaly an alpine glacier is a mountain glacier and it doesn't cover as much ground as the continental glacier.\nIt can be found in the high mountains where the temperatures are low enough for the ice to stay all over the year. Because of the temperature change their borders are not constant. Can be larger during the winter and smaller through the summer.\n\nThe continental glaciers are carachteristic for the poles. The cover enourmus surfaces like on Greenland, Arktic, Antharctik and lots of islands that suround them.
985736
Englacial debris.\n\nThis debris is eventually deposited and forms a moraine.
234915
How about any of these:\nSubway\nEllis Island - a huge % of us can be traced back to there\nErie Canal\nFinger Lakes - how glaciers caused them\n\nGood Luck
251465
Where ever there used to be a glacier, the northeast is a good place.  I live in upstate New York and go to school in Massachusetts and both areas are full of glacial erratics.  Long Island is just one big glacial erratic by itself.  Kinda neat, huh?
465922
One of the features that make up the earth's surface, such as a plain, mountain, or valley
495824
I belive you are tallking about a source for water.  It could be several thing, a glacier melting,  snow pack from the winter or natural springs.  Where the water in a mountain finds a hard rock and then will find the path of least resistance,  sometimes out the side of the mountain which would be a mountain spring.  But the mountain source is just the fact that the river is starting in mountain,  from a spring, winter melt off or glacier.  hope that helps.
389430
A fjord is created by inundation of a valley formed by a glacier.  They typically have very steep walls and very deep floors allowing ocean-going vessels to navigate them.\n\nA ria is a former river valley that has subsided below sea-level and flooded.  It is usually shallower than a fjord and often become estuaries with little fresh-water flow into them.
393129
FIrst the temperature-It is extremely cold in the winter, and cool in the summer.  Then generally the wind-wind can play a major role, especially in mountainous tundra-also in mountainous tundra is the problem of UV radiation.
995745
Complicted question. They're both made of a variety of rocks. Both contain ophiolitic rocks (oceanic crust), both contain accretionary melanges, made up of sea-floor sediments thrust repeatedly over each other. Both have limestone in them (top of Everest is limestone I think) and both have a load of granites in. Not a complete answer, but that would take forever.\n\nOrogenic belts (Alps, Himalayas, Andes) are complicated regions of deformation. However they have many similarities in the types of rocks they contain.
418848
You are misunderstanding a few different concepts here.  That is a pretty good definition of uniformitarianism...but it's important to understand that mountains are also building as they are eroding. An example of this is the Himalaya; they are sill rising about 3 inches every decade.  Hardly any erosion takes place on the higher peaks - too cold/covered in snow and ice.\n\nAlso, mountains build up in some areas, some areas erode, and many areas (of land) remain little changed (that's where you get your (relatively) young bones.  Many areas of land are also deposition areas that add material on top of old material (that's why you dig up bones and fossils).\n\nCatastrophism is now viewed as a very legitimate factor. Think of asteroid impacts, volcanoes, or the massive flooding caused by the end of the ice ages (do you think that little Colorado River carved the Grand Canyon?).\n\nSo we rectify both by seeing the proper blending of the two - a largely uniform Earth that is infrequently influenced by catastrophes.
883519
There is not really something like a critical point for glaciers. As long as temperatures are rising and are resulting in a negative mass balance the glaciers will keep on melting. But that's not irreversible - thinking rather in "geological" time scales, decades or hundreds or thousands of years. As soon as the mass balance gets positive (due to temperature and/OR more precipitation) glaciers will grow again.\n\nThinking e.g. of a huge volcanic eruption or a comet / asteroid hitting the earth and blowing dust into the atmosphere blocking sun light, that might lead to a global "freezing", maybe even to a next ice age.
979121
Permafrost--\n\n\nIn geology, permafrost or permafrost soil is a thermal condition where ground material stays at or below 0°C for two or more years. The presence of ice is not necessary, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts excess of the potential hydraulic saturation of the ground material. Most permafrost is located in high latitudes (e.g. North and South poles), but alpine permafrost exists at high altitudes.\n\nThe extent of permafrost can vary as the climate changes. Today, approximately 20% of the Earth's land mass is covered by permafrost (including discontinuous permafrost) or glacial ice. Overlying permafrost is a the layer of ground called the active layer that seasonally thaws during the summer. Plant life can be supported only within the active layer because growth can occur only in soil that is fully thawed for some part of the year. Thickness of the active layer varies by year and location but is typically 0.6 - 4 m (2 to 12 feet) thick. In areas of continuous permafrost and harsh winters the depth of the permafrost can be very great: 440m (1330 feet) at Barrow, Alaska, (600m (1970 feet) at Prudhoe Bay, Alaska, up to 726m (2382 feet) in the Canadian Arctic islands and as much as 1493m (4510 feet) in the northern Lena and Yana River basins in Siberia.