EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Sub-decadal scale coupling of the Moroccan Sidi Ali lake core record with historical and meteorological data for the last 120 years

Cathleen Kertscher1, Johannes Schmidt1, Helen Ballasus1, Birgit Schneider1, Anne Köhler1, Maja Flörke-Staats1, Elisabeth Dietze2, Abdelfattah Benkkadour3, Abdeslam Mikdad4, Lukas Werther5, Alexander Bolland6, Sylvain Pichat7, Hans von Suchodoletz1, William Fletcher8, Steffen Mischke9, and Christoph Zielhofer1
Cathleen Kertscher et al.
  • 1Institute for Geography, Leipzig University, Leipzig, Germany
  • 2Polar Terrestrial Environmental Systems, Alfred-Wegener-Institute for Polar and Marine Research, Research Unit Potsdam, Potsdam, Germany
  • 3Department of Earth Sciences, Cadi Ayyad University, Marrakech, Morocco
  • 4Institut National des Sciences de l'Archéologie et du Patrimoine, Rabat, Morocco
  • 5Department for Medieval Archaeology, University of Tübingen, Tübingen, Germany
  • 6Department of Environmental Sciences, University of Basel, Basel, Switzerland
  • 7Laboratoire de Geologie de Lyon (LGL-TPE), University of Lyon, France
  • 8Department of Geography, School of Environment, Education and Development, University of Manchester, Manchester, United Kingdom
  • 9School of Engineering and Natural Sciences, University of Iceland, Reykjavik, Iceland

The Western Mediterranean region including the North African desert margin faces major environmental challenges in the backdrop of global climate change in terms of rising temperatures, a higher recurrence of drought events and a decrease in annual precipitation. As a condition to state further prospects, it is crucial to comprehend past and present hydro-climatic patterns. The Moroccan Middle Atlas is considered a transition zone between Atlantic, Mediterranean and Saharan air masses and is therefore of unprecedented interest in order to comprehend regional climate variability and to assess emerging hydrological, geomorphological and ecological impacts. Despite the growing number of limnological studies from the Middle Atlas, there still is a strong need for coupling palaeolimnological results at the sub-recent time scale with historical cartographic information, meteorological variables and underlying climatic forcing. Lake Sidi Ali (33°03’ N, 5°00’ W, 2080 m a.s.l.) provides a unique archive for understanding environmental changes throughout the 20th century. At least for the past 100 years the lake has experienced a minimum of three significant lake level changes in the order of several meters. We were able to reconstruct and quantify these alternations with the help of historical sources, topographic maps and satellite imagery. In addition, we implemented a multi-proxy analytical approach on a 145-cm long sediment record, including δ18O and δ13C isotope analysis of ostracod shells and CNS elemental analysis. A reliable age model based on 25 210Pb measurements and one radiocarbon dated cedar needle enables the linkage of sediment geochemical variations to lake level changes based on an instrumental record and historic topographic maps. We use meteorological precipitation and temperature data to evaluate the main drivers controlling these fluctuations. Furthermore, we have indications for a temporal coupling of Atlantic climate patterns (North Atlantic Oscillation, NAO; Atlantic Multidecadal Oscillation, AMO) with Sidi Ali lake level development.

How to cite: Kertscher, C., Schmidt, J., Ballasus, H., Schneider, B., Köhler, A., Flörke-Staats, M., Dietze, E., Benkkadour, A., Mikdad, A., Werther, L., Bolland, A., Pichat, S., von Suchodoletz, H., Fletcher, W., Mischke, S., and Zielhofer, C.: Sub-decadal scale coupling of the Moroccan Sidi Ali lake core record with historical and meteorological data for the last 120 years, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8823,, 2021.

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