1,2,3,3,4,4,4,5,4,4,6,4,7,8,- 1University of Bergen, Geophysical Institute, Norway (hans.christian.steen-larsen@uib.no)
- 2Niels Bohr Institute, Physics of Ice, Climate and Earth, Copenhagen, Denmark
- 3Ca' Foscari University of Venice, Department of Environmental Science, Informatics and Statistics, Venice-Mestre, Italy
- 4Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- 5University of Göttingen, Geoscience Center, Goldschmidtstr. 1–3, 37077 Göttingen, Germany
- 6Department of Geosciences, Tübingen University, Tübingen, Germany
- 7Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Telegrafenberg A45, 14473 Potsdam, Germany
- 8Faculty of Geosciences, University of Bremen, Bremen, Germany, MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
- 9Laboratoire des Sciences du Climat et de l’Environnement, Gif-sur-Yvette, France
- 10Norwegian Polar Institute, Tromsø, Norway
While most of the below 700ka section of the Beyond EPICA ice core has been measured for water isotopic composition in 2.5 cm samples, a sub-section (depth 2473-2475 meters) has been cut into 1.25 cm. These ultra-high-resolution samples have been measured side-by-side with the 2.5 cm samples from the same depth, allowing a direct comparison with minimal calibration or instrument drift-induced uncertainty. With great care for optimal measurement quality, we present here a comparison of the samples, with average precisions (+/- 1 STD) of 0.03 o/oo and 0.07 o/oo for ẟ18O and ẟ2H, respectively, and average accuracies of 0.03 o/oo and 0.4 o/oo for ẟ18O and ẟ2H, respectively.
Variations between the 1.25 cm and 2.5 cm samples that cannot be attributed to measurement uncertainty are observed. Our ultra-high-resolution measurements provide critical insights into intra-core variability, and we argue that ice cores, when possible, should be measured at the highest resolution to obtain optimal information about past climate variability.
How to cite: Steen-Larsen, H. C., Phumchat, N., Gkinis, V., Stenni, B., Dreossi, G., Zannoni, D., Hörhold, M., Behrens, M., Wilhelms, F., Freitag, J., Weikusat, I., Jansen, D., Laepple, T., Minster, B., Landais, A., and Isaksson, E.: Ultra-High-resolution ẟ18O and ẟ2H measurements on the Beyond EPICA ice core: new insights into signal preservation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14467, https://doi.org/10.5194/egusphere-egu26-14467, 2026.
