Glacial landscapes are characterized by dramatic local relief, but they
also commonly exhibit high-elevation, low-relief surfaces(1-7). These
surfaces have been attributed to glacial headward erosion in Alpine
settings(1,2). However, the timing and processes responsible for their
formation in northern high-latitude regions remain elusive(4,7). Here we
estimate the rate of fjord erosion from geophysical relief(8,9) and
compare that with the erosion reflected by offshore sedimentation in
western Scandinavia during the late Pliocene and Quaternary glaciations
(0-2.8 million years ago). We find that the sediments generated by fjord
erosion over the entire western Scandinavia accounts for only 35-55% of
the total sediment volume deposited off the coast of Norway. This large
mismatch implies that during this period, significant erosion must have
also taken place away from the fjords at high elevation and indicates a
bimodal distribution of glacial erosion(10). Furthermore, comparing the
distribution of the high-elevation, low-relief surfaces with estimates
of the long-term glacier equilibrium line altitude supports the idea
that effective erosion in extensively glaciated areas limits topographic
height, a process known as the glacial buzzsaw(2,6,11,12). We therefore
conclude that glacial and periglacial processes have a substantial
impact on the formation of low-relief surfaces observed(1-7) in
glaciated mountain belts and high-latitude continental margins.