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Marine gateways play a critical role in the exchange of water, heat, salt, and nutrients between oceans and seas. Changes in gateway geometry can significantly alter both the pattern of global ocean circulation and climate. Today, the volume of dense water supplied by Atlantic–Mediterranean exchange through the Gibraltar Strait is among the largest in the global ocean. For the past 5 My, this overflow has generated a saline plume at intermediate depths in the Atlantic that deposits distinctive contouritic sediments and contributes to the formation of North Atlantic Deep Water. This single gateway configuration only developed in the Early Pliocene. During the Miocene, two narrow corridors linked the Mediterranean and Atlantic: one in northern Morocco and the other in southern Spain. Formation of these corridors followed by progressive restriction and closure resulted in extreme salinity fluctuations in the Mediterranean, leading to the precipitation of the Messinian Salinity Crisis salt giant. International Ocean Discovery Program (IODP) Expedition 401 is the offshore drilling component of a Land-2-Sea drilling proposal, Investigating Miocene Mediterranean–Atlantic Gateway Exchange (IMMAGE). Its aim is to recover a complete record of Atlantic–Mediterranean exchange from its Late Miocene inception to its current configuration by targeting Miocene offshore sediments on either side of the Gibraltar Strait. Miocene cores from the two precursor connections now exposed on land will be obtained by future International Continental Scientific Drilling Program (ICDP) campaigns.
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This content will become publicly available on July 7, 2026
Mediterranean–Atlantic Gateway Exchange
Marine gateways play a critical role in the exchange of water, heat, salt, and nutrients between oceans and seas. Changes in gateway geometry can significantly alter both the pattern of global ocean circulation and climate. Today, the volume of dense water supplied by Atlantic–Mediterranean exchange through the Gibraltar Strait is among the largest in the global ocean. For the past 5 My, this overflow has generated a saline plume at intermediate depths in the Atlantic that deposits distinctive contouritic sediments and contributes to the formation of North Atlantic Deep Water. This single gateway configuration only developed in the Early Pliocene. During the Miocene, two narrow corridors linked the Mediterranean and Atlantic: one in northern Morocco and the other in southern Spain. Progressive restriction and closure of these corridors resulted in extreme salinity fluctuations in the Mediterranean and the precipitation of the Messinian Salinity Crisis salt giant. International Ocean Discovery Program (IODP) Expedition 401 is the offshore drilling component of a Land-2-Sea drilling proposal, Investigating Miocene Mediterranean–Atlantic Gateway Exchange (IMMAGE). Its aim is to recover a complete record of Atlantic–Mediterranean exchange from its Late Miocene inception to its current configuration by targeting Miocene offshore sediments on either side of the Gibraltar Strait. Miocene cores from the two precursor connections now exposed on land will be obtained by future International Continental Scientific Drilling Program (ICDP) campaigns.
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- PAR ID:
- 10613537
- Publisher / Repository:
- International Ocean Discovery Program
- Date Published:
- Journal Name:
- Proceedings of the International Ocean Discovery Program Expedition reports
- Volume:
- 401
- ISSN:
- 2377-3189
- ISBN:
- 978-1-954252-94-3
- Subject(s) / Keyword(s):
- International Ocean Discovery Program, IODP, JOIDES Resolution, Expedition 401, Mediterranean–Atlantic Gateway Exchange, Earth Systems Models, Site U1609, Site U1610, Site U1385, Site U1611, IMMAGE, Land-2-Sea, Gibraltar, Messinian Salinity Crisis, Messinian, Tortonian, Miocene, Pliocene, contourite, turbidite, slump, debrite, hemipelagite, cemented carbonate, sapropel, organic-rich mud, sandstone, drift, mixed system, Mediterranean Overflow Water, MOW, Mediterranean, outflow, salt giant, evaporite, gypsum, halite, precession, Atlantic, exchange, Portuguese margin, Gulf of Cádiz, Alborán Basin, Sines drift
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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