Spatial mapping of multi-year superimposed ice on the glacier Kongsvegen, Svalbard

摘要: Ground-penetrating radar (GPR) and satellite ERS-2 synthetic aperture (SAR) are used to map the thickness extent of superimposed ice (SI) zone on surge-type glacier Kongsvegen, Svalbard. GPR imagery shows sub-horizontal SI layers lying unconformably above a discrete boundary. Below this boundary, has signature similar that further down-glacier in ablation zone. This boundary is posited represent closing crevasses were created during last surge Kongsvegen � 1948. Open would have interrupted formation sheet due efficient vertical drainage snowpack. Aerial photographs suggest closed sometime period 1956-66. A classified SAR image from 2003 delineate The agrees well with mapped by GPR. Using spatial depth distribution, we estimate mean annual accumulation be 0.16 0.06 m w.e. -1 (locally up 0.43 w.e.). corresponds 15-33% local winter balance 5-10% total measured since 1987.