The movement of glaciers

When ice accumulation of more and more thick, due to ice body itself formed by the weight of the pressure, coupled with the effects of gravity, you can make ice at the bottom of the flow occurs along the downward slope. Glacier movement in the river flow faster than the much smaller, one-year forward only dozens of meters to several hundred meters. The movement of glaciers in general very slow. 

And the impact of glacier movement factors include the following: 


(1) the ground slope: the greater the slope of the moving sooner. 

(2) glacier thickness and temperature. The thicker the ice is greater pressure, the greater the kinetic energy, the faster movement. Higher temperature when the activities of ice stronger, faster mobile. 

(3) the ground smoothness. More smooth surface resistance is smaller glaciers mobile, mobile sooner, on the contrary, if the rough surface, the greater the resistance, then moving slowly. 

(4) ice-melting content. If the temperature increases, part of the ice melted into water, the ice-melting content increased, increased mobility, glaciers move faster 

(5) glaciers carry the effect of rock debris. Rock debris carried by glaciers more, then the greater the pressure, the stronger the kinetic energy, mobile sooner. 

Continental glacier screwdown crust due to the weight of the General Assembly, the central part of the base rock will become irregular disk, not into a massive, but like a lot of plane-like movement. Valley glacier sliding part of the fastest in the glaciers at the top, at the bottom of the rock base due to friction while moving very slowly. The speed of glacier movement in various parts of the same glaciers are different in different parts of glaciers will have different forms of movement, the movement of glaciers by internal flow and sliding at the bottom of the composition of two parts. In each cross-section of the glacier, its surface is greater than at the central rate of both sides because both sides of the rock by glaciers on both sides of the resistance; the same ice surface is also moving faster than its in-house. 


Generally speaking, the middle of the flow of a faster rate than on both sides, at the top than the bottom faster. The movement of glaciers is mainly composed of two parts, one part of the campaign is the internal movement of glaciers, increasing from bottom to top; another part of the movement is at the bottom of the sliding glacier, known as "the end of Waterloo" , is at the bottom of glacial melt water because of the smooth rocks at the end of the slide. In the movement of glaciers, the slip at the end of the campaign is greater than its own internal glacier movement. Therefore, the movement of glaciers is mainly relying on "the end of Waterloo." For each glacier is concerned, have a stacking area and ablation area, separated from the snow line, in the online snow and ice melt ice plot equal role. Accumulation in the top of the snow belt continuously added, while the valleys on both sides of the supply of a large number of ice and snow avalanche; ablation zone occurred in the melting ice and snow and evaporation. 

If added to the volume of glaciers and depletion of the volume just to balance, the glaciers on the stay is no longer advance; if added to the amount in excess of wear and tear, then to move forward into the glacier; but if more than the addition of the volume of wear and tear, the glacier retreat backwards. The so-called retreat, does not refer to the retreat of glaciers true, because glaciers are fixed and moving down, so is the retreat of glaciers shrinking range. At present, most of the world's glaciers are in retreat phase. 

In addition, before and after the addition of glaciers could be divided into two bands (that is, the accumulation zone and ablation zone), the glacier can also be divided into two parts from top to bottom, above some of the more brittle fracture zone known as the (zone of fracture); below bear part above the weight and pressure, such as a plastic body as slowly as the movement of the sliding belt (zone of flow). In addition, the speed of glacier flow as a result of changes in flow caused by done (extending flow) and compressed stream (compressing flow) in Glacier Valley, slowing down the slope of the paragraph, extrusion and thickening of the ice to form a compressed stream; the other hand, ice layer occurred elongated form done flow. 

As the glaciers of the fluid around the lower part of different ideas, Kennedy brittle upper body strength of the ice is very low, coupled with friction on both sides of the valley and glacial valley beneath the ground level of undulating terrain, so the surface of many glacier crevasse (crevasses) . Glacier crevasse is the most obvious, the most abundant structure, the upper body Kennedy brittle ice rattle when the ice below under continuous flow of the role of the enormous cracks. Crevasse is a tension crack is due to the different glacier movement arising. The location of glaciers in different games produce different crevasse, in general the main crevasse include: 

(1) horizontal crevasse when the glacier movement, glacier at the bottom of rugged rocks, so that the speed of glacier flow different, when the glaciers formed to accelerate the flow would have done the horizontal crevasse, horizontal crevasse and glacier flow vertical direction. 


(2) the edge of glacier crevasse Movement, along the valley walls generated by pulling trailers. 

(3) vertical crevasse expansion when the glaciers began to form at the end of glacier crevasse, vertical crevasse and parallel to the direction of glacier flow. 

(4) radial crevasse in the glacier is the most peripheral, when the glacier developed into a prominent part of the circle formed. 

Glacier factors control the flow of ice thickness, temperature, slope characteristics, valleys and glaciers in the shape of the rock and by taking the amount of such debris. If the glaciers at the bottom and between caused by a layer of ice-melting water film on the movement of glaciers can be of great help. Regardless of the movement of glaciers by which factors, has always been forward movement of glaciers.