Eleanor Georgiadis

Eleanor Georgiadis

Visitor

My interest in geosciences spans from the ocean to the terrestrial realm, investigating microscale to regional processes on timescales ranging from seasons to millennia.

Current Work: Oxidative Processes in the Weathering Zone

Picture showing the landscape at the Draix Bleone Observatory. The badland mountain terrain presents highly eroded material with deep incisions and sparse vegetation..

Field site at the Draix Bléone Observatory, France (photo courtesy of Prof Bob Hilton).

I am currently applying my knowledge in organic geochemistry to better understand oxidative processes in, and carbon emissions from sedimentary rocks as a ROC-CO2 Postdoctoral Research Associate. More specifically, I am measuring phospholipid fatty acids to quantify microbial biomass in shale samples from the Draix Bléone Observatory, France. By comparing my biomass calculations with carbon dioxide fluxes from the study sites, my work will shed light on the role of microbial activity in oxidative weathering processes in sedimentary rocks.

Past Work: High Arctic Paleoceanography

Following a BSc in Life and Earth Sciences, I enrolled in an MSc in Oceanography at the University of Bordeaux, France, driven by my eagerness to learn more about the natural world. I received an IdEx and CRSNG scholarship from the University of Bordeaux, France and Université Laval, Canada to study the Holocene history of Nares Strait, northernmost Baffin Bay for my PhD. The study area has undergone dramatic change over the last ca 10,000 years following the retreat of glacial ice that engulfed the strait during the Last Glacial Maximum (ca 18,000 years ago).

Today, the unique sea ice conditions in Nares Strait play an important role in the oceanographic and environmental conditions in Northwest Greenland. Worryingly, recent trends of declining sea ice cover in Nares Strait are accelerating ice loss from the Arctic Ocean and threaten one of the most important oases in the Arctic.

I was fortunate enough to participate in the 2016 ARCTICNET campaign on the Canadian Coast Guard Ship Amundsen to retrieve marine sediment cores to investigate the strait’s Holocene history. This allowed me to address the lack of pre-satellite records of sea ice conditions in Nares Strait as part of my PhD.

The picture shows two icebergs carrying lithic debris in very still waters in a High Arctic Fjord.

Debris-ridden icebergs in Talbot Fjord, northernmost Baffin Bay, photographed during the 2016 ARCTICNET campaign on the CCGS Amundsen at one of the coring sites of my PhD.

Microscopic picture of an Arctic benthic foraminifera, Nonionella labradorica, measuring approximately 500 micrometers.

Nonionella labradorica from a marine sediment core retrieved off Northwest Greenland. 

Using sea ice biomarkers (IP25 and HBI III) and microfossil (foraminifera) assemblages, I was able to reconstruct seasonal sea ice cover in the strait over the past ca 9,000 years, showing that they are highly sensitive to changes in atmospheric temperatures and potentially along-strait wind strength.

Nares Strait is also a case study for the abrupt deglacial opening of a strait in response to climate change. Through a high-resolution investigation of the sedimentological structure and geochemical composition of our marine archive, I was able to better constrain the chronology of the connection of the Arctic Ocean to Baffin Bay and characterise the subsequent geomorphological reorganisation of Nares Strait.

Ribeiro, S., Limoges, A., Massé, G., Johansen, K.L., Colgan, W., Weckström, K., Jackson, R., Georgiadis, E., Mikkelsen, N., Kuijpers, A., Olsen, J., Olsen, S., Nissen, N., Thorbjørn, J.A., Strunk, E., Wetterich, S., Syvärante, J., Henderson, A.C.G., Mackey, H., Taipale, S., Jeppesen, E., Larsen, N.K., Crosta, X., Giraudeau, J., Wengrat, S., Nuttall, M., Gronnow, B., Mosbech, A., Davidson, T.A. Vulnerability of the North Water ecosystem to climate change. Nature Communications. DOI s41467-021-24742-0

 

Jackson, R., Kyorning, A., Limoges, A., Georgiadis, E., et al. Holocene polynya dynamics and their interactions with oceanic heat transporting northern Baffin Bay. Scientific Reports, 2021. DOI s41598-021-88517-9  

 

Georgiadis, E., Giraudeau, J., Jennings, A., Limoges, A., Jackson, R., Ribeiro, S., Massé, G. Local and regional controls on Holocene sea ice conditions in Nares Strait, NW Greenland. Marine Geology, 2020. DOI 10.1016/j.margeo.2020.106115

 

Giraudeau, J., Georgiadis, E., Caron, M., Martinez, P., St-Onge, G., Billy, I., Lebleu, P., Ther, O., Massé, G. A high-resolution elemental record of post-glacial lithic sedimentation in Upernavil Trough, western Greenland: history of ice-sheet dynamics and ocean circulation changes over the last 9,100 years. Global and Planetary Change, 2020. DOI 10.1016/j.gloplacha.2020.103217

 

 Limoges, A., Weckström, K., Ribeiro, S., Georgiadis, E., Elnegaard Hansen, K., Marinez, P., Seidenkrantz, M.-S., Giraudeau, J., Crosta, X., Massé, G. Learning from the past: impact of the Arctic Oscillation on sea ice and marine productivity of northwest Greenland over the last 9,000 years. Global Change Biology, 2020. DOI 10.1111/gcb.15334

 

 Caron, M., St-Onge, G., Montero-Serrano, J.-C., Rochon, A., Georgiadis, E., Giraudeau, J., Massé, G. Holocene chronostratigraphy of northeastern Baffin Bay based on radiocarbon and palaeomagnetic data. Boreas, 2019. DOI 10.1111/bor.12346

 

 Georgiadis, E., Giraudeau, J., Martinez, P., Lajeunesse, P., St-Onge, G., Schmidt, S., Massé, G. Deglacial to post-glacial history of Nares Strait, NW Greenland: a marine perspective from Kane Basin. Climate of the Past, 2018. DOI 10.5194/cp-2018-78