Morphology of Frost Polygons As Related To Ground Slope in Eastern Greenland

This paper describes polygonal frost-patterned ground on level terraces, modification of the polygons by solifluction to garlands on slopes of 5° to 35°, modification of the garlands to rock stripes on slopes of 20° to 45°, collapse of stripes into jumbled rock glaciers on slopes of 35° to 60°, or more commonly, modification of stone stripes back through the sequence of stripes and garlands where the slope shallows toward the valley floor. The subsurface structures of eight polygons, two garlands, and two stone stripes were exposed by trenching. The garlands and stone stripes were on a slope lying between a flat-lying raised beach and a very slightly inclined valley floor. The trenching proved the rock-rimmed areas to be three dimensional with limited depth. Within each ring there was a vertical as well as horizontal sorting of soil, sand, and rock fragments, with the finest fractions toward the center