Palaeoclimatic significance of rock glaciers in Sierra Nevada. A first approach

B. Palade, D. Palacios Estremera, A. Gómez Ortiz

Abstract


This paper provides an inventory of 36 rock glaciers located in the western part of Sierra Nevada mountains. All the forms fall in the category of talus rock glaciers. All the rock glaciers were classified as relict except the rock glacier situated in Corral del Veleta which still preserves certain amount of ice in its interior. The cartographic information was included and analyzed within a Geographical Information System (GIS) and the results show that the rock glaciers in Sierra Nevada are located between 2460 and 3360 m a.s.l., on slopes of 21º on average that receive low amounts of solar radiation, although due to particular wind direction and snow accumulation conditions in Sierra Nevada, there is a significant number of rock glaciers lying on the southern slopes. The present altitudinal distribution of rock glaciers suggests average temperatures 6º C lower than today at the time of their initiation. Two rock glaciers as well as one abrasion surface were sampled and dated using the 36Cl cosmogenic exposure method. The results show that the rock glaciers developed immediately after the Pleistocene glaciers retreated (14 – 15 ka) and were still active throughout the first part of the Holocene (8-7 ka). The rock glacier situated in the Corral del Veleta is a recent example of rock glacier formation in a deglaciated environment during the final phase of the Little Ice Age.



DOI: http://dx.doi.org/10.18172/cig.1258

© Universidad de La Rioja, 2013

ISSN 0211-6820

EISSN 1697-9540