Review status: this preprint is currently under review for the journal CP.
Precise timing of MIS 7 sub-stages from the Austrian Alps
Kathleen A. Wendt1,Xianglei Li2,R. Lawrence Edwards2,Hai Cheng2,3,and Christoph Spötl1Kathleen A. Wendt et al.Kathleen A. Wendt1,Xianglei Li2,R. Lawrence Edwards2,Hai Cheng2,3,and Christoph Spötl1
Received: 11 Nov 2020 – Accepted for review: 17 Nov 2020 – Discussion started: 20 Nov 2020
Abstract. Determining the precise timing of glacial terminations and the interglacials that follow is key to addressing questions surrounding future warming. Here, we present a high-precision record of Termination III (TIII), Termination IIIa (TIIIa), the penultimate interglacial (MIS 7), and the penultimate glacial inception (MIS 7/6 transition) from Spannagel Cave in the Austrian Alps. Using state-of-the-art mass spectrometry techniques, we have constructed a uranium-series dated chronology with relative age uncertainties averaging 1.7 ‰ (2σ) during our study period (247 to 191 thousand years before present). Results reveal the onset of TIII at 242.5 ± 0.2 ka and the duration of MIS 7e between 241.8 to 236.7 (±0.6) ka. Depleted δ18O values indicating MIS 7b center at 229.5 ± 2.3 ka. An abrupt shift towards higher δ18O values at 217.1 ± 0.5 ka marks the beginning of TIIIa. Two periods of high δ18O values (greater than −10 ‰) between 215.9–213.3 and 204.3–197.5 (±0.4) ka coincide with interglacial substages MIS 7c and 7a, respectively. Two newly collected stalagmites from Spannagel Cave (SPA146 & 183) provide high-resolution replications of the latter portion of the MIS 7a/6e transition, which occurred between approximately 197.1 and 191.4 (±0.3) ka. The resulting multi-stalagmite timeseries provides important chronological constraints on climate shifts in Europe and the North Atlantic during MIS 7. This study also provides a clear answer to the exact timing of TIIIa, which has been previously debated.
The timing of North Atlantic climate changes during the penultimate interglacial (MIS 7) and terminations III-IIIa are debated. In this study we present a multi-stalagmite climate record from the Austrian Alps, whose winter temperatures are sensitive to the North Atlantic realm. The record spans 247000 to 191000 years ago with an average age uncertainty of 370 years (2 sigma). This unprecedented age control provides important time constraints on rapid climate shifts in the Alps throughout MIS 7.
The timing of North Atlantic climate changes during the penultimate interglacial (MIS 7) and...