Short-term climate changes in the southern Aegean Sea over the last 48,000 years

High-resolution palaeoenvironmental changes, corresponding to a mean time interval of 450 years covering the last 48,000 years, were examined in a core from the Cretan Basin in the southern Aegean Sea. The intensity and duration of the climatic and oceanographic events were determined by examining the compositional changes in the planktonic foraminifera and pollen assemblages, along with the delta O-18 signal of Globigerinoides ruber. A reconstruction of sea-surface temperatures was attempted using the Modem Analogue Technique (MAT). In total, 10 stadials and 6 interstadials occurred over the last 48,000 years. These fluctuations in climatic conditions coincide with fluctuations documented in the western and central Mediterranean and seem to be associated with Dansgaard-Oeschger events. Some of these climatic fluctuations are correlated with changes in the vegetation in the surrounding land. Between 48 and 10 cat kyr BP the most pronounced stadials occurred at 41 cat kyr BP (C69-ST10) and at 13 cat kyr BP (C69-ST4). These events are characterized by: (i) high positive delta O-18 values of Globigerinoides ruber, (ii) drops in SST and (iii) increases in aridity. These events may be correlated with the Heinrich H4 event and the Younger Dryas event, respectively. Two other stadials at 23 cat kyr BP (C69-ST6) and at 16 cat kyr BP (C69-ST5) which are characterized by increases in the abundance of the cold plaktonic foraminifera species and increases in aridity may be correlated with the H2 and H1 events, respectively. The dominant planktonic foraminiferal species during the stadials witch are correlated with the Heinrich events were Turborotalita quinqueloba and Globorotalia scitula. The most pronounced interstadials occurred between 39.5 and 38.5 cal kyr BP (C69-IST6) and between 25 and 24 cat kyr BP (C69-IST3) and are characterized by depletion in delta O-18 values, increases in SST and increases in humidity. The former event coincides with the formation of the sapropelitic layer S2. In the Holocene the most pronounced stadial occurred between 8 and 6.5 cat kyr BP (C69-ST2), during the interruption of S1 and is characterized by a reduction in SST and an increase in aridity. The most pronounced interstadials of Holocene occurred during the formation of S1a and S1b between 9 and 8 cat kyr BP (C69-IST1) and between 6.5 and 5.5 cal kyr BP (C69-TST2), respectively. These events are characterized by depletion in delta O-18 values, increased SST and an increase in humidity as is indicated by the expansion of temperate evergreen and Mediterranean taxa in the pollen record. (c) 2005 Elsevier B.V. All rights reserved.