EGU23-17219, updated on 06 Jan 2024
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Investigating Miocene Mediterranean-Atlantic Gateway Exchange (IMMAGE): the first land-2-sea drilling project

Rachel Flecker1, Olivia Gaitonde1, and the IMMAGE Co-I Team*
Rachel Flecker and Olivia Gaitonde and the IMMAGE Co-I Team
  • 1BRIDGE, School of Geographical Sciences, University of Bristol, UK.
  • *A full list of authors appears at the end of the abstract

Marine gateways play a critical role in the exchange of water, heat, salt and nutrients between oceans and seas. The advection of dense waters helps drive global thermohaline circulation and, since the ocean is the largest of the rapidly exchanging CO2 reservoirs, this advection also affects atmospheric carbon concentration. Changes in gateway geometry can therefore significantly alter both the pattern of global ocean circulation and associated heat transport and climate, as well as having a profound local impact.

Today, the volume of dense water supplied by Atlantic-Mediterranean exchange through the Gibraltar Strait is amongst the largest in the global ocean. For the past five million years this overflow has generated a saline plume at intermediate depths in the Atlantic that deposits distinctive contouritic sediments in the Gulf of Cadiz and contributes to the formation of North Atlantic Deep Water. This single gateway configuration only developed in the early Pliocene, however. During the Miocene, a wide, open seaway linking the Mediterranean and Atlantic evolved into two narrow corridors: one in northern Morocco; the other in southern Spain. Formation of these corridors permitted Mediterranean salinity to rise and a new, distinct, dense water mass to form and overspill into the Atlantic for the first time. Further restriction and closure of these connections resulted in extreme salinity fluctuations in the Mediterranean, leading to the formation of the Messinian Salinity Crisis salt giant.

IMMAGE is a land-2-sea drilling project designed to recover a complete record of Atlantic-Mediterranean exchange from its Late Miocene inception to its current configuration. This will be achieved by targeting Miocene offshore sediments on either side of the Gibraltar Strait with IODP during Expedition 401 (December 2023-February 2024) and recovering Miocene core from the two precursor connections now exposed on land with ICDP. The scientific aims of IMMAGE are to constrain quantitatively the consequences for ocean circulation and global climate of the inception of Atlantic-Mediterranean exchange; to explore the mechanisms for high amplitude environmental change in marginal marine systems and to test physical oceanographic hypotheses for extreme high-density overflow dynamics that do not exist in the world today on this scale.


Javier Hernandez-Molina; Estefanía Llave Barranco; Domenico Chiarella; Timothy Herbert; Sonya Legg; Nadia barhoun; Hajar El Talibi; Amine Manar; María del Pilar Mata Campo; María Isabel Reguera García; Cristina Roque; Gemma Ercilla; Wout Krijgsman; Frits Hilgen; Abdellah Salem; Guillermo Booth Rea; Francisco Jiménez; Marcus Gutjahr; Francisco Jiménez; Santiago Ledesma Mateo; Paul Meijer; María Isabel Reguera García; Francisco Javier Rodríguez Tovar; César Rodríguez Ranero; Ferran Estrada; Damien Do Couto; Francisco J. Sierro; Zakaria Yousfi; Mohamed Nahim; Michael Rogerson; Duncan Wallace;;; Asmae Benarchid

How to cite: Flecker, R. and Gaitonde, O. and the IMMAGE Co-I Team: Investigating Miocene Mediterranean-Atlantic Gateway Exchange (IMMAGE): the first land-2-sea drilling project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17219,, 2023.