DYPOLE: Dynamics of polar confined basins - The Eurasia Basin from breakup in greenhouse to present in icehouse conditions

Through the DYPOLE project, we increase the understanding of the complex interplay between geological processes that have formed the continental margin north of Svalbard/Barents Sea and adjacent areas of the Arctic Ocean. Key questions include: (1) How did the continent split up between the Lomonosov Ridge and the Barents shelf about 55 million years ago and how did the Arctic Ocean open up since then? (2) When was a deep-water connection established between the Arctic and Atlantic oceans through the Fram Strait, and how did this affect geological and oceanographic conditions? (3) How has this development affected the climate from "greenhouse" conditions with surface water temperatures of up to 25°C to "icehouse" conditions with extensive land and sea ice cover over the last 10-15 million years? (4) When and how was the Barents Shelf uplifted so that large volumes of rock were removed and transported into the Arctic Ocean, where they now provide a unique archive reflecting the geological and climatic development over millions of years? We continue to analise geophysical and geological data collected offshore (2022, GoNorth), and onshore (2023, Woodfjorden-Bockfjorden expedition). In 2024 we communicated several preliminary results at national and international conferences. We discovered that pervasive magmatism had an impact 10 million years ago on a large region including Svalbard and SW Eurasia Basin. We improved our geophysical database (shared with NOR-R-AM2 project) and disseminated theses results at conferences and through publications. This project was part of the 3rd GoNorth expedition to NE Greenland and Fram Strait where we collected new geophysical and geological data in September 2024.

The main goal of the project is to obtain an understanding of the interplay between the various tectonic, magmatic, and sedimentary processes that have shaped the northern Barents Sea-Svalbard margin, caused continental breakup and variation in spatial and temporal oceanic accretion in the Eurasia Basin. Moreover, we aim to establish links between the tectono-magmatic history of the Cenozoic Arctic and oceanographic and climatic changes. Three time intervals are particularly important in the development of the Eurasia Basin and adjacent regions in the Arctic: 1) Late Paleocene continental breakup and continental margin formation; 2) Early Eocene and Oligocene changes in seafloor spreading and Oligocene volcanic plateau emplacement; and 3) Neogene gateway opening, margin uplift and establishment of an icehouse Arctic. Notably, these tectonic events seem to coincide with distinct climatic events that punctuated the Cenozoic greenhouse-icehouse transition, from surface-water temperatures of up to 25 °C during the Paleocene-Eocene, to icehouse conditions with extensive land and sea-ice cover from Miocene onward. Each of the primary objectives will be addressed in a dedicated scientific work package (WP), but considerable amount of data, theoretical approach and methodology will be shared among the WPs: WP1: Breakup and crustal architecture; WP2: Eocene-Miocene crustal evolution of the Eurasia Basin; WP3: Greenhouse - Icehouse fluctuations in the Arctic: onset and origin. The project results will be integrated and synthesised in a separate WP4. We will combine a broad range of data and methods, and will employ a novel approach where the crustal, sedimentary and oceanographic data will be jointly presented and analysed. We will study in a multi-disciplinary and holistic way the formation of an enclosed oceanic basin in the polar region and the implications for ocean and climate dynamics.