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Dr. Oliver Knebel

Postdocs

Group: 

Coral Paleoclimatology

Phone: 

+49 421 218-65759

Email:

Room: 

Pavillon, 1100

Oliver Knebel

Sci­en­tific­ally in­de­pend­ent group at MARUM

Research Interests

  • Paleoclimatology and Paleoceanography
  • Geochemistry
  • Coral reefs under ocean acidification and warming
  • Biomineralisation

Common Era ENSO variability in the West Central Pacific inferred from isotopic and trace element analysis of Porites microatolls

The primary driver of the inter-annual climate variability in the Pacific is the El Niño Southern Oscillation (ENSO). However, to date, instrumental records of the Pacific climate are too short to determine if recent changes in ENSO variability are primarily due to anthropogenic or natural forcing, and the adaptability of coral communities to increasing thermal stress is not thoroughly understood.

This research aims to construct proxy records of ENSO activity and climate conditions, as well as coral calcification, covering the Common Era (0 – 2000 CE) for the West Central Pacific from Porites spp. microatoll skeletons. In particular, coupled isotopic (δ18O) and trace element (Sr/Ca) analyses in high (~bimonthly) resolution will permit for reconstructions in paleo-SST and seawater δ18O (δ18Osw). Furthermore, a γ-densitometer is employed to determine variations in skeletal density that will allow, in conjunction with measurements of annual extension rates, to construct records of coral calcification.

By comparing constructed coral growth and paleo-SST records it will be possible to study how changes in tropical climate conditions have impacted coral health during the Common Era. Ultimately, results of this study will improve projections of future ENSO activity and coral calcification in response to ongoing anthropogenic warming.

Cur­ri­cu­lum Vi­tae

2022 - present PostDoc; MARUM, Uni­versity of Bre­men, Germany, and Goethe-University, Frankfurt am Main, Germany
2021 - 2022 PostDoc; MARUM, Uni­versity of Bre­men, Germany
2017 - 2021 PhD; University of Auckland, New Zealand, and NOCS, Southampton, UK with Prof. Paul Kench and Prof. Gavin Foster
2014 - 2017 MSc; Free University Amsterdam, Netherlands, and NIOZ, Texel, Netherlands
2010 - 2014

BSc; Goethe University, Frankfurt am Main, Germany

Publications

Knebel, O., Felis, T., Asami, R., Deschamps, P., Kölling, M., & Scholz, D. (2024).Last deglacial environmental change in the tropical South Pacific from Tahiti corals.Paleoceanography and Paleoclimatology, 39, e2022PA004585. https://doi.org/10.1029/2022PA004585

Knebel, O., Carvajal, C., Kench, P., Gehrels, R. (2023). Spatial pH variability of coral reef flats of Kiritimati Island, Kiribati. Marine Environmental Research,105861, ISSN 0141-1136. https://doi.org/10.1016/j.marenvres.2022.105861

Knebel, O., Kench, P., Foster, G., Carvajal, C., de la Vega, E., Sayani, H., Cobb, K. M. (2022). Ocean acidification in the industrial era: Boron isotope-pH proxy records from Pacific microatolls. Poster presented at: International Coral Reef Symposium 2022; July 2022; Bremen. https://doi.org/10.13140/RG.2.2.33119.74404

Knebel O., Carvajal, C., Standish, C. D., de La Vega, E., Chalk, T. B.. Ryan, E. J., Ford, M., Foster, G., Kench, P. (2021). Porites calcifying fluid pH on seasonal to diurnal scales. Journal of Geophysical Research: Oceans, 126, e2020JC016889. https://doi.org/10.1029/2020JC016889