Gulf of Corinth IODP Expedition 381 Inorganic Geochemistry

Lead Research Organisation: University of Leeds
Department Name: School of Earth and Environment

Abstract

The Gulf of Corinth has experienced repeated changes from a lake to a marine embayment in response to sea level fluctuations during the last ice ages. Such dramatic environmental changes will have strongly affected the ecosystem in the Gulf of Corinth, and with it the cycling of bioessential elements like carbon and phosphorus. In similar situations where a lake was flooded and gradually salinified by the incursion of seawater, like in the Black Sea or Baltic Sea at the end of the last ice age, very distinct geochemical regimes developed in the water column that had strong impacts on the chemistry of the water column: A stable stratification developed between fresh lake waters on top and saline seawater below, and this restricted mixing of the water column. As a result, the deep waters became completely free of oxygen, and thus inhospitable to multi-cellular life - even poisonous due to the production of hydrogen sulphide. It is currently unknown if the Gulf of Corinth experienced similarly dramatic environmental changes and the development of an oxygen-free deep water mass. If so, this would have had important implications for the preservation of organic carbon in the sediments - the raw material for our modern oil and gas resources - as organic matter is much less degraded under oxygen-depriven conditions. Our geochemical methods will allow usfor the first time, to track changes in water column and sediment chemistry across a couple of representative lake-to-ocean and ocean-to-lake transitions in the Gulf of Corinth.

Planned Impact

Although this short project is based on fundamental research without an immediate economic, political or societal impact, it offers various opportunities for public engagement in marine environmental research:

The Gulf of Corinth Expedition 381 team (with a British Co-Chief Scientist) has already had various outreach events in Greece to inform the public about the research plans and objectives, and more such events are planned.
IODP has regular outreach activities with links to ongoing or recently completed expeditions at major international research conferences (including EGU, AGU, GSA), and it is anticipated that the PDRA will attend at least one international conference to present results of her research to the wider scientific community.

The Gulf of Corinth is an active Earthquake area and was in the past repeatedly flooded (maybe catastrophically) by the sea, which makes this project attractive for media coverage.

The outreach and communications team at the Bremen Core Repository is highly experienced in promoting IODP-related activities to the public media.

The PDRA is planning to present aspects of her research at stand-up comedy events and public outreach events (Bright Club, Soapbox Science, Famelab).

Publications

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Description The Gulf of Corinth supposedly shifted from marine to lacustrine conditions (i.e., from an ocean to a lake) as the sea level fluctuated with waxing and waning of ice sheets over the past hunderds of thousands of years. Our data show that there were more short-term transitions than assumed based on a standard sea level curve. In addition, it seems that the chemical composition of the seawater flooding the Gulf of Corinth during sea level rises had a fundamentally different composition than the global ocean seawater. Finally, we can show that the transitions were less abrubt, and probably more complex, than a simple shift from one end member state to another.
Exploitation Route I don't know
Sectors Other