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.[1] The stratigraphy is detected by radio-echo sounding. The Raymond effect arises from the unusual flow properties of ice. It is of importance because it provides field evidence for the flow properties of ice [2] . In addition, it permits dating of changes in ice flow and the establishment of changes in ice thickness.[3] The effect was first predicted by Charles F. Raymond.[4] Raymond Arches and the Raymond Effect have been observed at numerous other ice divides e.g. Siple Dome; [5] Fletcher Ice Rise, Berkner Island[6] [7]; Roosevelt Island [3][7]; Korff Ice Rise. [8]
Ice viscosityisstress-dependent, and in zones where the (deviatoric) stresses are low, the viscosity becomes very high. Near the base of ice-sheets, stress is proportional to the surface slope, at least when averaged over a suitable horizontal distance. At the flow divide, the surface slope is zero, and calculations show that the viscosity increases[4]. This diverts ice flow laterally, and is the cause of the characteristic anticlines, which are in effect draped over the high viscosity area.
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