EGU21-8650
https://doi.org/10.5194/egusphere-egu21-8650
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Centennial to millennial-scale variability of Holocene climate and environmental dynamics in the western Mediterranean (Lake Sidi Ali, Middle Atlas, Morocco)

Johannes Schmidt1, Cathleen Kertscher1, Markus Reichert1, Helen Ballasus1, Birgit Schneider1, Elisabeth Dietze2, Rik Tjallingii3, Abdelfattah Benkkadour4, Abdselam Mikdad5, Lukas Werther6, Alexander Bolland7, Sylvain Pichat8, Hans von Suchodoletz1, William Fletcher9, Steffen Mischke10, and Christoph Zielhofer1
Johannes Schmidt et al.
  • 1Institute of Geography, Leipzig University, Leipzig, Germany (j.schmidt@uni-leipzig.de)
  • 2Polar Terrestrial Environmental Systems, Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam, Potsdam, Germany
  • 3GFZ -German Research Centre for Geosciences, Section Climate Dynamics and Landscape Evolution, Telegrafenberg, Potsdam, Germany
  • 4Department of Earth Sciences, Cadi Ayyad University, Marrakech, Morocco
  • 5Institut National des Sciences de l’Archéologie et du Patrimoine, Rabat, Morocco
  • 6Department for Medieval Archaeology, University of Tübingen, Tübingen, Germany
  • 7Department of Environmental Sciences, University of Basel, Basel, Switzerland
  • 8Laboratoire de Geologie de Lyon (LGL-TPE), University of Lyon, Lyon, France
  • 9Department of Geography, School of Environment, Education and Development, University of Manchester, Manchester, UK
  • 10School of Engineering and Natural Sciences, University of Iceland, Reykjavík, Iceland

The Western Mediterranean region including the North African desert margin is considered one of the most sensitive areas to future climate changes. In order to refine long-term scenarios for hydrological and environmental responses to future climate changes in this region, it is important to improve our knowledge about past environmental responses to climatic variability at centennial to millennial timescales. During the last two decades, the recovery and compilation of Holocene records from the subtropical North Atlantic and the Mediterranean Sea have improved our knowledge about millennial-scale variability of the Western Mediterranean palaeoclimate. The variabilities appear to affect regional precipitation patterns and environmental systems in the Western Mediterranean, but the timescales, magnitudes and forcing mechanisms remain poorly known. To compare the changes in Holocene climate variability and geomorphological processes across temporal scales, we analysed a 19.63-m long sediment record from Lake Sidi Ali (33°03’ N, 5°00’ W, 2080 m a.s.l.) in the sub-humid Middle Atlas that spans the last 12,000 years (23 pollen-based radiocarbon dates accompanied with 210Pb results). We use calibrated XRF core scanning records with an annual to sub-decadal resolution to disentangle the complex interplay between climate changes and environmental dynamics during the Holocene. Data exploration techniques and time series analysis (Redfit, Wavelet) revealed long-term changes in lake behaviour. Three main proxy groups were identified (temperature proxies: 2ky, 1ky and 0.7ky cycles; sediment dynamic proxies: 3.5ky, 1.5ky cycles; hydrological proxies: 1.5ky, 1.2ky, 0.17ky cycles). For example, redox sensitive elements Fe and Mn show 1ky cycles and higher values in the Early Holocene and 1.5ky cycles and lower values in the Mid- to Late Holocene. All groups show specific periodicities throughout the Holocene, demonstrating their particular climatic and geomorphological dependencies. Furthermore, we discuss these periodicities relating to global and hemispheric drivers, such as the North Atlantic Oscillation (NAO), El-Niño Southern Oscillation (ENSO), Innertropical Convergence Zone variability (ITCZ) and North Atlantic cold relapses (Bond events).

How to cite: Schmidt, J., Kertscher, C., Reichert, M., Ballasus, H., Schneider, B., Dietze, E., Tjallingii, R., Benkkadour, A., Mikdad, A., Werther, L., Bolland, A., Pichat, S., von Suchodoletz, H., Fletcher, W., Mischke, S., and Zielhofer, C.: Centennial to millennial-scale variability of Holocene climate and environmental dynamics in the western Mediterranean (Lake Sidi Ali, Middle Atlas, Morocco), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8650, https://doi.org/10.5194/egusphere-egu21-8650, 2021.

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