EGU General Assembly 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Southern Chilean continent-ocean interaction over the last glacial cycle

Julia Rieke Hagemann1, Frank Lamy1, Kana Nagashima2, Naomi Harada2, Shinya Iwasaki2, Alfredo Martínez-Garcia3, Jérôme Kaiser4, Helge W. Arz4, Norbert Nowaczyk5, Carina Lange6,7,8, and Ralf Tiedemann1
Julia Rieke Hagemann et al.
  • 1Alfred-Wegener-Institute, Geoscience, Germany (
  • 2Japan Agency For Marine-Earth Science and Technology (JAMSTEC)
  • 3Max-Planck-Institut für Chemie Mainz (MPIC)
  • 4Leibniz-Institut für Ostseeforschung Warnemünde (IOW)
  • 5Helmholtz-Zentrum Potsdam (GFZ)
  • 6Centro Oceanográfico COPAS Sur-Austral and Centro FONDAP-IDEAL, Concepción, Chile
  • 7Centro de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universitdad Austral de Chile, Valdivia, Chile
  • 8Departamento de Oceanografía, Universidad de Concepción, Chile

Available sea surface temperature (SST) records from the subantarctic SE Pacific reveal large amplitude changes at orbital time-scales. High sedimentation rates along the southern Chilean margin provided higher resolution records back to ~70 ka showing millennial-scale SST variations paralleling temperatures reconstructed in Antarctic ice-cores.

Here we present high-resolution millennial-scale SST and subsurface temperature records based on core MR16-09 PC03 covering a complete glacial/interglacial cycle back to Marine Isotope Stage 6, including a high-resolution record of the Eemian. Located on the Chilean margin at the bifurcation of the Antarctic Circumpolar Current into the Peru-Chile Current to the North and the Cape Horn Current to the South, core MR16-09 PC03 is in an ideal position to study the continent-ocean interactions, including changes in water masses, ice sheet formation, precipitation and vegetation.

We used alkenones and GDGTs to determine SST (UK’37) and subsurface temperatures (TEXH86; 0 - 200 m), and integrated these results with XRF core scanner and planktic δ18O data (G. bulloides). During the Eemian, SSTs and subsurface temperatures were ~2° C and ~4° C, higher than during the Holocene, respectively. The high Eemian temperatures at our site are roughly consistent with the few available subantarctic SST records. The large temperature difference in the subsurface water masses between the Eemian and the Holocene could be explained by a deeper thermocline during the Eemian. During the last glacial period, the strongly fluctuating temperatures averaged ~8° C at the surface and ~6° C in the subsurface. The relative amount of C37:4 alkenone (%C37:4) show a drastic increase during the glacial period, especially in Marine Isotope Stage 3 in concentration. High %C37:4 values suggest increased freshwater supply, which could be related to fluctuations of the Patagonian Ice sheet and/ or precipitation on the adjacent land. The sedimentation rate and other terrigenous proxies, e.g. Titanium, BIT, Iron and Alkanes, confirm such increased and highly variable terrestrial inputs.

How to cite: Hagemann, J. R., Lamy, F., Nagashima, K., Harada, N., Iwasaki, S., Martínez-Garcia, A., Kaiser, J., Arz, H. W., Nowaczyk, N., Lange, C., and Tiedemann, R.: Southern Chilean continent-ocean interaction over the last glacial cycle, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-768,, 2020.


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