Geomorphologic and paleoclimatic evidence of Holocene glaciation on Mount Olympus, Greece

• Published in: The Holocene
• Main Authors: Styllas, Michael Nikolaos, Schimmelpfennig, Irene, Ghilardi, Matthieu, Benedetti, Lucilla
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2015
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: http://dx.doi.org/10.1177/0959683615618259; http://journals.sagepub.com/doi/pdf/10.1177/0959683615618259; http://journals.sagepub.com/doi/full-xml/10.1177/0959683615618259

This study investigates the possibility of Holocene glaciation on Mount Olympus (Greece) with a respective local temperature–precipitation equilibrium line altitude (TP-ELA) at c. 2200 m a.s.l., based on geomorphologic and paleoclimatic evidence. At present, the local TP-ELA is situated above the mountain’s summit ( c. 2918 m a.s.l.), but permanent snowfields and ice bodies survive within Megala Kazania cirque between c. 2400 and c. 2300 m a.s.l., because of the cirque’s maritime setting that results from its close proximity ( c. 18 km) to the Aegean Sea and of the local topographical controls. The snow and ice bodies occupied a considerably larger area and attained a stabilization phase between AD 1960 and 1980, also manifested from aerial photographs, a period characterized by increased winter precipitation ( P w ) with subsequent TP-ELA depression to c. 2410 m a.s.l. Mid- to late-20th-century P w and TP-ELA variations exhibit negative correlations with the winter North Atlantic Oscillation index (NAO w ) at annual and multidecadal (30 years) timescales. Late Holocene (AD 1680–1860) reconstructed summer mean temperatures were lower by T s < 1.1°C in relation to the reference period between AD 1960 and 1980 and were also superimposed to negative NAO w phases, thus bracketing this time interval as a favorable one to glacial formation and/or advance. Millennial-scale annual precipitation reconstructions at the hypothesized TP-ELA ( c. 2200 m a.s.l.) point the period between 8 and 4 kyr BP as another glacier-friendly candidate. The mid-Holocene rather simplistic sequence of potential glacial advance phase was disturbed by short-lived cold climatic deteriorations, well-documented over the northern Aegean region that may partly explain the multicrested shape of the highest ( c. 2200 m a.s.l.) morainic complex of Megala Kazania cirque.