A paleoprecipitation and paleotemperature reconstruction of the Last Interglacial in the southeastern Alps

The Last Interglacial (LIG, similar to 130-116 ka) was one of the warmest interglacials of the past 800 000 years and an important test bed for future climate conditions warmer than today. LIG temperature reconstructions from marine records and paleoclimate models show that middle and high northern latitudes were considerably warmer (by about 2 to 5 degrees C) compared to today. In central Europe, the LIG has been widely studied using pollen and more recently chironomids preserved in lake sediments. While these bio-archives document temperature changes across the LIG, they are commonly poorly constrained chronologically. Speleothems and fluid inclusions contained therein offer superior age control and provide information on past climate, including qualitative and partly also quantitative records of temperature and precipitation. Here, we present a precisely dated fluidinclusion record based on seven speleothems from two caves in the southeastern Alps (Obir and Katerloch) and use a delta H-2 =T transfer function to reconstruct regional LIG temperatures. We report a temperature change across the glacialinterglacial transition of 5.2 similar to 3.1 ffiC and peak temperatures at similar to 127 ka of 2.4 +/- 2.8 degrees C above today's mean (1973-2002). The fluid-inclusion delta H-2 record of these speleothems exhibits millennial-scale events during the LIG that are not well expressed in the delta O-18(calcite). The early LIG in the southeastern Alps was marked by an important climate instability followed by progressively more stable conditions. Our record suggests that the southeastern Alps predominantly received Atlantic-derived moisture during the early and middle LIG, while more Mediterranean moisture reached the study site at the end of the LIG, buffering the speleothem delta(18)Ocalcite signal. The return towards colder conditions is marked by an increase in delta C-13 starting at similar to 118 ka, indicating a decline in the vegetation and soil activity.