Holocene Glacier and Climatic Variations, Kebnekaise Mountains, Swedish Lapland

Abstract

Detailed mapping of well-preserved moraine systems fronting 23 small glaciers in the Kebnekaise Mountains in Swedish Lapland reveals that the Holocene was punctuated by four prolonged intervals of glacier expansion. The youngest interval corresponds to the well-known Little Ice Age and lasted from at least A. D. 1500 until the 20th century. Minor fluctuations superimposed on this broad interval of expansion are dated by lichenometry and historical records; they culminated about A.D. 1916, 1890, 1850, 1780, 1710, and 1500 to 1640. The next youngest interval, which also involved a number of minor fluctuations spread over several centuries, is associated with C14 dates of 2320±160 years B. P. (St-3811) and 2460±90 years B. P. (I-6854) (Corrected for variation in atmospheric C14: 2370 and 2475–2720 years B. P., respectively). The two oldest glacial intervals center around tentative lichenometric dates of 5000 and 8000 years B. P., respectively.Advances of the two older intervals were the least extensive. Advances of the two youngest intervals were approximately equal in magnitude although the relative extents of drift sheets suggest that in many cases the older of these two intervals may have been slightly more intense. Within the Little Ice Age the advances between A. D. 1500 and 1640 were commonly the most extensive.Two features commonly encountered in the Kebnekaise Mountains point to the complexity of moraine construction. The first involves large moraine ridges that were built up over a time span of up to 8000 years by proximal enlargement of an original moraine obstruction by drift related to successively younger advances. The second feature involves numerous moraines that have survived documented glacier overriding essentially intact.