Thursday, 6 December 2012

Frequently crampons are required to travel efficiently over snow and ice. Crampons have 8-14 spikes and are attached to a mountaineer's boots. They are used on hard snow (neve) and ice to provide additional traction. Using various techniques from alpine skiing and mountaineering to ascend/descend a mountain is a form of the sport by itself, called ski mountaineering. Ascending and descending a snow slope safely requires the use of an ice axe and many different footwork techniques that have been developed over the past century, mainly in Europe. The progression of footwork from the lowest angle slopes to the steepest terrain is first to splay the feet to a rising traverse, to kicking steps, to front pointing the crampons


12.30pm. 6.12.12. 


The progression of ice axe technique from the lowest angle slopes to the steepest terrain is to use the ice axe first as a walking stick, then a stake, then to use the front pick as a dagger below the shoulders or above, and finally to swinging the pick into the slope over the head. These various techniques may involve questions of differing ice-axe design depending on terrain, and even whether a mountaineer uses one or two ice axes. Anchors for the rope in snow are sometimes unreliable, and include the snow stakes, called pickets, deadman devices called flukes which are fashioned from aluminium, or devised from buried objects that might include an ice axe, skis, rocks or other objects. Bollards, which are simply carved out of consolidated snow or ice, also sometimes serve as anchors

At times snowbridges can be as thin as a few inches. Climbers use a system of ropes to protect themselves from such hazards. Teams of two to five climbers tie into a rope equally spaced. If a climber begins to fall the other members of the team perform a self-arrest to stop the fall



Earth flow

This process causes the flow to thicken. The bulbous variety of earthflows are  much more common than their rapid counterparts

Earthflows are downslope, viscous flows of saturated, fine-grained materials, which move at any speed from slow to fast. Typically, they can move at speeds from 0.17 to 20 km/h. Though these are a lot like mudflows, overall they are slower moving and are covered with solid material carried along by flow from within. They are different from fluid flows in that they are more rapid. Clay, fine sand and silt, and fine-grained, pyroclastic material are all susceptible to earthflows. The velocity of the earthflow is all dependent on how much water content is in the flow itself: if there is more water content in the flow, the higher the velocity will be.

These flows usually begin when the pore pressures in a fine-grained mass increase until enough of the weight of the material is supported by pore water to significantly decrease the internal shearing strength of the material. This thereby creates a bulging lobe which advances with a slow, rolling motion






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