Ice-wedge polygons and solifluction in the Adventdalen area, Spitsbergen, Svalbard

In the Adventdalen area, ice-wedge polygons are numerous from sea level up to altitudes of at least 500 m a.s.l. In higher areas, polygons are found in weathering material, mostly on bedrock Cretaceous in age or older. Many polygons are found on slopes inclined up to at least 25°. Polygonal patterns on slopes seem to be undisturbed by mass movement, indicating low rates of solifluction in the active layer. Polygons on slopes are discussed in relation to measurements of solifluction movement over a period of 14 years. Maximum solifluction rates are measured to 4.3 cm a year in a solifluction lobe. On smooth surfaces where solifluction lobes are absent, movement rates are much lower (Table 1). Polygons in higher parts of the terrain may be very old, since these areas most probably had permafrost during the whole postglacial time, as well as in earlier glacial periods with cold-based ice.