Climate variability in the SE Alps of Italy over the past 17 000 years reconstructed from a stalagmite record

Stalagmite SV1 from Grotta Savi, located at the SE margin of the European Alps (Italy), is the first Alpine speleothem that continuously spans the past c . 17kyr. Extension rate and δ¹⁸O_c record for the Lateglacial probably reflect a combination of temperature and rainfall, with rainfall exerting the dominant effect. Low speleothem calcite δ¹⁸ O_c values were recorded from c . 14.5 and 12.35 kyr, during GI-1 (Bølling— Allerød) interstadial, which in our interpretation, was warm and wet. The GS-1 (Younger Dryas) was characterized by a shift to heavier δ¹⁸ O_c, coinciding with δ¹³C_c enrichment and extremely low extension rate (<8 μm/year). These characteristics indicate that GS-1 climate was cool and dry in the SE Alps. Calibration using historical data revealed that there is a positive δ¹⁸O_c/dT relationship. A 1°C rise in mean annual temperature should correspond to c . 2.85% increase of SV-1 δc¹⁸O_c. We reconstructed a slow and steady temperature rise of c . 0.5°C since 10 kyr BP, in broad agreement with reconstructions from pollen data for SE Europe. Stalagmite SV1 indicates that climate variability in the SE Alps has been influenced by the Mediterranean Sea for the past c . 17 kyr.