It is becoming increasingly urgent to study the impacts of climate change on the global ocean system. Future projections indicate significant changes in the Mediterranean and Atlantic circulation system, which could have unpredictable climatic consequences, especially for one of the most influential ocean currents in the global climate: the Atlantic Meridional Overturning Circulation (AMOC).
This highly sensitive ocean system, which is showing signs of weakening, could collapse in the future due to the effects of climate change and polar ice melt, with effects on global ocean regulation and the climate that are difficult to predict.
Studying the changes that could lead AMOC to collapse is the aim of the new MORIA 2 oceanographic campaign, led by the University of Barcelona. From 22 June to 7 July, it will study the circulation of the Mediterranean Outflow Water (MOW) and its impact on the Atlantic Ocean circulation. These water masses that leave the Mediterranean Sea are a constant and powerful flow of warm and more saline water, moving from the Strait of Gibraltar to higher latitudes in the Atlantic Ocean.
AMOC: a current in danger of collapsing?
On board the vessel Odón de Buen, the expedition will sail from the port of Vigo to Reykjavík (Iceland) to study the behaviour of the AMOC along the European Atlantic margin. This campaign is the continuation of MORIA 1, which was carried out in 2025 aboard the oceanographic vessel Sarmiento de Gamboa and successfully covered the Bay of Biscay and the Iberian Peninsula margin.
The MORIA project is led by researchers Leopoldo Pena and Isabel Cacho, with the prominent participation of experts Jaime Frigola and Galderic Lastras, all of whom are members of the Marine Geosciences Research Group (Gmar) at the UB’s Faculty of Earth Sciences.
“MORIA 2 picks up exactly where MORIA 1 was unable to reach due to weather reasons: the Irish margin, the waters around the United Kingdom and Denmark, expanding all the way to Iceland. This continuity is essential to obtain a complete view of the journey of Mediterranean waters across the entire European Atlantic margin,” explain Leopoldo Pena and Jaime Frigola, from the UB’s Department of Earth and Ocean Dynamics, who lead the new campaign.
“The preliminary results of MORIA 1 have revealed significant scientific surprises, particularly regarding the main export routes of Mediterranean water to higher latitudes. These findings reinforce the importance of completing the campaign and raise new questions that MORIA 2 will be able to address,” the experts detail.
Other institutions involved in the project and the campaign are the Institute of Marine Sciences (ICM-CSIC), the Spanish Institute of Oceanography in Vigo (IEO-CSIC), the University of Las Palmas de Gran Canaria, the Marine Research Institute (IIM-CSIC), the Andalusian Institute of Earth Sciences (IACT) and University College Cork (Ireland).
From geochemical analyses to paleoclimate reconstruction
During the expedition, experts will precisely characterize the Mediterranean waters — using geochemical tracers, physicochemical parameters, and other techniques — as they move northwards, in order to study the potential impact of changes in the MOW on the AMOC. Sediment samples will also be collected from the ocean floor to reconstruct the variability of the MOW in the recent past, and to assess the possible effects of changes in this water mass on the AMOC.
The facilities of the Laboratory of Radiogenic and Environmental Isotopes (LIRA), located at the Faculty of Earth Sciences, will play a key role in analysing and reconstructing the chemical properties of the samples obtained, as well as quantifying the amount of Mediterranean water masses exported to higher latitudes.
The MORIA project (2023-2027) is part of Strategic Action 5 — Climate, Energy and Mobility — of the 2021-2023 State Research, Technical and Innovation Plan, an initiative that promotes research into the impacts of climate change. It was submitted under the 2022 call for Knowledge Generation Projects from the former Ministry of Science and Innovation.
The daily activities of the MORIA 2 oceanographic campaign can be tracked on this website.