Last Glacial Maximum and the Gschnitz stadial in the Maritime Alps according to ¹⁰Be cosmogenic dating

Two glacial deposits in the G esso valley ( M aritime, A lps) have been 10 Be ‐dated at 20 140±1080 (weighted mean± SD ) and 16 590±970 years, respectively, thus constraining the L ast G lacial M aximum ( LGM ) and G schnitz stadials in the southwestern part of the A lps. The LGM age is chronologically coherent with MIS 2 and synchronous with most other LGM moraines in the A lps. The G schnitz stadial also appears to be in agreement with the ages obtained from other A lpine sites and with H einrich E vent I . This suggests that the A lpine glaciers reacted simultaneously and essentially synchronously with the climate change associated with H einrich E vent 1. The E quilibrium L ine A ltitudes ( ELA s) of the LGM and G schnitz reconstructed palaeoglaciers are 1850 and 1910 m a.s.l., respectively. The ELA comparison across the A lps indicates that the palaeoclimate of the M aritime A lps during the LGM was rather different from that of other A lpine sectors. However, the similar G schnitz ELA value between the G esso valley and other sites across the mountain chain indicates that Alpine glaciers responded with the same intensity to the climate change associated with H einrich E vent I . Overall, these results suggest that the interaction between the atmospheric circulation of air masses and local A lpine orography was more complex than has previously been argued.