Eivind Olavson Straume

• Taylor, Victoria E.; Piasecki, Alison; Straume, Eivind Olavson & Meckler, A. Nele (2026). Divergent deep-sea temperatures in the Pacific and Atlantic during the onset of Antarctic glaciation. Nature Geoscience. ISSN 1752-0894. doi: 10.1038/s41561-026-02106-x. Full text in Research Archive Show summary

  Approximately 34 million years ago at the Eocene–Oligocene transition, Earth cooled sufficiently to sustain a large-scale Antarctic ice sheet. Our understanding of this climatic pivot point relies heavily on oxygen isotope records from deep-sea dwelling benthic foraminifera (δ18Ob), which document a globally synchronous increase, interpreted to reflect a combination of deep-sea cooling and ice-sheet growth. Here we present benthic foraminiferal clumped isotope-derived deep-sea temperature records from two ocean basins, spanning the Eocene–Oligocene transition. Our records from the equatorial Pacific and North Atlantic exhibit divergent temperature behaviour, in contrast to similar δ18Ob signals, with earlier Pacific and later Atlantic cooling compared with the δ18Ob increase. These differences are probably masked in the δ18Ob records by contrasting salinity gradients required to maintain similar densities. A reversed interbasin temperature gradient relative to today, with an overall cooler deep North Atlantic, suggests a very different deep-ocean structure, with potentially two different southern-sourced deep-water masses. The divergent properties of these two water masses may reflect different interactions between the temporally and spatially variable early cryosphere and deep-water formation regions, indicating a direct influence of the cryosphere on deep-water properties.

• Straume, Eivind Olavson; Faccenna, Claudio; Becker, Thorsten W.; Steinberger, Bernhard; Licht, Alexis & Sembroni, Andrea [Show all 8 contributors for this article] (2025). Collision, mantle convection and Tethyan closure in the Eastern Mediterranean. Nature Reviews Earth & Environment. 6, p. 299–317. doi: 10.1038/s43017-025-00653-2. Full text in Research Archive Show summary

  The Tethys Seaway once linked the Atlantic and Indo-Pacific oceans. Its gradual shallowing and closure impacted global ocean circulation, faunal diversification and climatic changes. In this Review, we evaluate the tectonic causes and the topographic changes across the Eastern Mediterranean over the past 66 Ma and explore the consequences of Tethys Seaway closure. Mantle convection led to collisional tectonic processes, mountain building and crustal thickening along the Tethyan realm. The Ethiopian flood basalts mark the arrival of the Afar plume at ~30 Ma, followed by northward-trending volcanic activity indicating that plume material had moved to northwest Arabia by ~20 Ma. Plume-induced mantle flow generated kilometre-scale uplift across East Africa, at ~8° N at ~35 Ma, and along Arabia and led to the formation of the Gomphotherium land bridge at 30° N, ~20 Ma. Afro-Arabian uplift contributed to the development of modern-like Asian monsoons, and the land bridge between Africa and Asia enabled one of the greatest faunal interchanges of the Cenozoic. The gradual shoaling and final closure of the Tethys Seaway likely facilitated the transition towards a stronger overturning circulation in the North Atlantic, contributing to the Cenozoic cooling trend. Future research should incorporate more detailed spatial and temporal uplift models into paleogeography and paleoclimate models to better simulate consequences for ocean circulation, climate and biogeographic dispersals.

• Gaina, Carmen; Jakobsson, Martin; Straume, Eivind Olavson; Timmermans, Mary-Louise; Boggild, Kai & Bünz, Stefan [Show all 8 contributors for this article] (2025). Arctic Ocean bathymetry and its connections to tectonics, oceanography and climate. Nature Reviews Earth & Environment. 6, p. 211–227. doi: 10.1038/s43017-025-00647-0. Full text in Research Archive Show summary

  For at least the past 50 million years, the Arctic region has had a major role in regulating global climate regimes and their variations through time. In this Review, we discuss the role of the Arctic oceanic basin and its complex bathymetry in controlling ocean circulation and marine cryosphere development. The spatial distribution and depth of various seafloor features, such as ocean gateways, submarine plateaus and continental shelves, influence the pathways of ocean currents, both today and in the past. The Arctic Ocean was an enclosed basin until the Early Eocene (56–48 million years ago), when the Eurasian Basin started to form and a shallow sea connected the Arctic to the Tethys Ocean. The connections with the North Atlantic and the global ocean through shallow and deep gateways prompted the transition from a global greenhouse to icehouse climate. However, the Arctic Ocean remains underexplored, as less than one-quarter of its seafloor is mapped in detail. Future integrated geoscience research, modern bathymetric mapping technology and active international programmes are needed to close these data gaps

• Straume, Eivind Olavson; Steinberger, Bernhard; Becker, Thorsten W. & Faccenna, Claudio (2024). Impact of mantle convection and dynamic topography on the Cenozoic paleogeography of Central Eurasia and the West Siberian Seaway. Earth and Planetary Science Letters. ISSN 0012-821X. 630. doi: 10.1016/j.epsl.2024.118615. Full text in Research Archive Show summary

  The West Siberian Seaway connected the Tethys to the Arctic Ocean in the Paleogene and played an important role for Eurasian-Arctic biogeography, ocean circulation, and climate. However, the paleogeography and geological mechanisms enabling the seaway are not well constrained, which complicates linking the seaway evolution to paleoenvironmental changes. Here, we investigate the paleogeography of the Peri-Tethys realms for the Cenozoic time (66–0 Ma), including the West Siberian Seaway, and quantify the influence of mantle convection and corresponding dynamic topography. We start by generating continuous digital elevation models for Eurasia, Arabia, and Northern Africa, by digitizing regional paleogeographic maps and additional geological information and incorporate them in a global paleogeography model with nominal million-year resolution. Then we compute time-dependent dynamic topography for the same time interval and find a clear correlation between changes in dynamic topography and the paleogeographic evolution of Central Eurasia and the West Siberian Seaway. Our results suggest that mantle convection played a greater role in Eurasian paleogeography than previously recognized. Mantle flow may have influenced oceanic connections between the Arctic and global ocean providing a link between deep mantle convection, surface evolution, and environmental changes. Our reconstructions also indicate that the Arctic Ocean may have been isolated from the global ocean in the Eocene, even if the West Siberian Seaway was open, as the Peri-Tethys – Tethys connection was limited, and the Greenland-Scotland Ridge was a landbridge.

• Zhang, Zijian; Zhang, Zhongshi; Nummelin, Aleksi Henrynpoika; Straume, Eivind Olavson; Meckler, Anna Nele & Langebroek, Petra Margaretha [Show all 9 contributors for this article] (2024). Influence of plate reference frames on deep-time climate simulations. Global and Planetary Change. ISSN 0921-8181. 233. doi: 10.1016/j.gloplacha.2023.104352. Full text in Research Archive
• Straume, Eivind Olavson; Nummelin, Aleksi Henrynpoika; Gaina, Carmen & Nisancioglu, Kerim Hestnes (2022). Climate transition at the Eocene-Oligocene influenced by bathymetric changes to the Atlantic-Arctic oceanic gateways. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 119(17). doi: 10.1073/pnas.2115346119. Full text in Research Archive Show summary

  The Eocene–Oligocene Transition (∼33.9 Ma) marks the largest step transformation within the Cenozoic cooling trend and is characterized by a sudden growth of the Antarctic ice sheets, cooling of the interior ocean, and the establishment of strong meridional temperature gradients. Here we examine the climatic impact of oceanic gateway changes at the Eocene–Oligocene Transition by implementing detailed paleogeographic reconstructions with realistic paleobathymetric models for the Atlantic–Arctic basins in a state-of-the-art earth system model (the Norwegian Earth System Model [NorESM-F]). We demonstrate that the warm Eocene climate is highly sensitive to depth variations of the Greenland–Scotland Ridge and the proto–Fram Strait as they control the freshwater leakage from the Arctic to the North Atlantic. Our results, and proxy evidence, suggest that changes in these gateways controlled the ocean circulation and played a critical role in the growth of land-based ice sheets, alongside CO2-driven global cooling. Specifically, we suggest that a shallow connection between the Arctic and North Atlantic restricted the southward flow of fresh surface waters during the Late Eocene allowing for a North Atlantic overturning circulation. Consequently, the Southern Hemisphere cooled by several degrees paving the way for the glaciation of Antarctica. Shortly after, the connection to the Arctic deepened due to weakening dynamic support from the Iceland Mantle Plume. This weakened the North Atlantic overturning and cooled the Northern Hemisphere, thereby promoting glaciations there. Our study points to a controlling role of the Northeast Atlantic gateways and decreasing atmospheric CO2 in the onset of glaciations in both hemispheres.

• Morée, Anne L.; Sun, Tianyi; Bretones, Anaïs; Straume, Eivind Olavson; Nisancioglu, Kerim Hestnes & Gebbie, Geoffrey (2021). Cancellation of the precessional cycle in δ18O records during the Early Pleistocene. Geophysical Research Letters. ISSN 0094-8276. 48(3). doi: 10.1029/2020GL090035. Full text in Research Archive Show summary

  The dominant pacing of glacial‐interglacial cycles in deep‐ocean δ18O records changed substantially during the Mid‐Pleistocene Transition. The precessional cycle (∼23 ky) is absent during the Early Pleistocene, which we show can be explained by cancellation of the hemispherically anti‐phased precessional cycle in the Early Pleistocene interior ocean. Such cancellation develops due to mixing of North Atlantic and Southern Ocean δ18O signals at depth, and shows characteristic spatial patterns. We explore the cancellation potential for different North Atlantic and Southern Ocean deep‐water source δ18O values using a tracer transport ocean model. Cancellation of precession occurs for all signal strengths and is widespread for a signal strength typical for the Early Pleistocene. Early Pleistocene precessional power is therefore likely incompletely archived in deep‐sea δ18O records, concealing the true periodicity of the glacial cycles in the two hemispheres.

• Straume, Eivind Olavson; Gaina, Carmen; Medvedev, Sergei & Nisancioglu, Kerim Hestnes (2020). Global Cenozoic Paleobathymetry with a focus on the Northern Hemisphere Oceanic Gateways. Gondwana Research. ISSN 1342-937X. 86, p. 126–143. doi: 10.1016/j.gr.2020.05.011. Full text in Research Archive Show summary

  The evolution of the Northern Hemisphere oceanic gateways has facilitated ocean circulation changes and may have influenced climatic variations in the Cenozoic time (66 Ma–0 Ma). However, the timing of these oceanic gateway events is poorly constrained and is often neglected in global paleobathymetric reconstructions. We have therefore re-evaluated the evolution of the Northern hemisphere oceanic gateways (i.e. the Fram Strait, Greenland–Scotland Ridge, the Central American Seaway, and the Tethys Seaway) and embedded their tectonic histories in a new global paleobathymetry and topography model for the Cenozoic time. Our new paleobathymetry model incorporates Northeast Atlantic paleobathymetric variations due to Iceland mantle plume activity, updated regional plate kinematics, and models for the oceanic lithospheric age, sediment thickness, and reconstructed oceanic plateaus and microcontinents. We also provide a global paleotopography model based on new and previously published regional models. In particular, the new model documents important bathymetric changes in the Northeast Atlantic and in the Tethys Seaway near the Eocene–Oligocene transition (~34 Ma), the time of the first glaciations of Antarctica, believed to be triggered by the opening of the Southern Ocean gateways (i.e. the Drake Passage and the Tasman Gateway) and subsequent Antarctic Circumpolar Current initiation. Our new model can be used to test whether the Northern Hemisphere gateways could have also played an important role modulating ocean circulation and climate at that time. In addition, we provide a set of realistic global bathymetric and topographic reconstructions for the Cenozoic time at one million-year interval for further use in paleo-ocean circulation and climate models.

• Straume, Eivind Olavson; Gaina, Carmen; Medvedev, Sergei; Hochmuth, Karsten; Gohl, Karsten & Whittaker, Joanne M. [Show all 9 contributors for this article] (2019). GlobSed: Updated Total Sediment Thickness in the World's Oceans. Geochemistry Geophysics Geosystems. 20(4), p. 1756–1772. doi: 10.1029/2018GC008115. Full text in Research Archive Show summary

  We present GlobSed, a new global 5‐arc‐minute total sediment thickness grid for the world's oceans and marginal seas. GlobSed covers a larger area than previously published global grids and incorporates updates for the NE Atlantic, Arctic, Southern Ocean, and Mediterranean regions, which results in a 29.7% increase in estimated total oceanic sediment volume. We use this new global grid and a revised global oceanic lithospheric age grid to assess the relationship between the total sediment thickness and age of the underlying oceanic lithosphere and its latitude. An analytical approximation model is used to mathematically describe sedimentation trends in major oceanic basins and to allow paleobathymetric reconstructions at any given geological time. This study provides a much‐needed update of the sediment thickness distribution of the world oceans and delivers a model for sedimentation rates on oceanic crust through time that agrees well with selected drill data used for comparison.

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• Straume, Eivind Olavson; Torsvik, Trond Helge & Domeier, Mathew Michael (2026). Paleogeography linking mantle processes, climate, and biotic evolution. Full text in Research Archive
• Straume, Eivind Olavson; Nummelin, Aleksi; Domeier, Mathew & Torsvik, Trond (2026). Phanerozoic paleogeography and its impact on long-term climatic change and habitability. European Geosciences Union General Assembly Abstracts. doi: 10.5194/egusphere-egu26-13853. Full text in Research Archive
• Åkesson, Henning; Straume, Eivind Olavson & Nisancioglu, Kerim Hestnes (2026). Ice music festival Oslo - science workshop. doi: https:/icemusicfestival.com/ice-music-oslo-2026. Full text in Research Archive
• Taylor, Victoria Emma; Meckler, Anna Nele; Rae, James; Ziegler, Martin; Inglis, Gordon & Lear, Caroline [Show all 18 contributors for this article] (2025). Early Eocene Ocean Circulation: Proxy-model agreements, mismatches, and avenues for future research. Full text in Research Archive
• Straume, Eivind & Nummelin, Aleksi Henrynpoika (2025). The role of paleogeography and CO2 in surface to deep ocean temperature gradients. Full text in Research Archive
• Straume, Eivind (2025). The influence of paleogeography on Cenozoic ocean circulation and climate. Full text in Research Archive
• Straume, Eivind (2025). Cenozoic Evolution of the Arctic Ocean. Full text in Research Archive
• Straume, Eivind Olavson; Aleksi, Nummelin; Victoria, Taylor; Meckler, Anna Nele & Zhang, Zhongshi (2024). The role of paleogeography and CO2 on Eocene deep-sea temperatures: A model-proxy comparison study. Full text in Research Archive
• Straume, Eivind Olavson; Shephard, Grace & Crameri, Fabio (2024). Building and establishing the open collection of geoscience graphics. Full text in Research Archive
• Straume, Eivind Olavson (2023). Deep time paleoclimate: The role of paleogeography, oceanic gateways, and the carbon cycle . Full text in Research Archive
• Shephard, Grace; Crameri, Fabio & Straume, Eivind Olavson (2023). Ongoing experiences in establishing and building a grass-roots science outreach initiative; the s-Ink.org graphics repository. Full text in Research Archive
• Shephard, Grace; Crameri, Fabio & Straume, Eivind Olavson (2023). Open graphics for open science; the s-Ink.org graphics repository. Full text in Research Archive
• Nisancioglu, Kerim Hestnes; Morée, Anne; Sun, Tianyi; Bretones, Anais Magali; Straume, Eivind Olavson & Gebbie, Geoffrey (2021). Cancellation of the precessional cycle in δ18O records during the Early Pleistocene. Full text in Research Archive Show summary

  The dominant pacing of glacial‐interglacial cycles in deep‐ocean δ18O records changed substantially during the Mid‐Pleistocene Transition. The precessional cycle (∼23 ky) is absent during the Early Pleistocene, which we show can be explained by cancellation of the hemispherically anti‐phased precessional cycle in the Early Pleistocene interior ocean. Such cancellation develops due to mixing of North Atlantic and Southern Ocean δ18O signals at depth, and shows characteristic spatial patterns. We explore the cancellation potential for different North Atlantic and Southern Ocean deep‐water source δ18O values using a tracer transport ocean model. Cancellation of precession occurs for all signal strengths and is widespread for a signal strength typical for the Early Pleistocene. Early Pleistocene precessional power is therefore likely incompletely archived in deep‐sea δ18O records, concealing the true periodicity of the glacial cycles in the two hemispheres.

• Crameri, Fabio & Straume, Eivind Olavson (2019). Colour maps. [Internet]. A Slice of CEED. Full text in Research Archive
• Morée, Anne; Sun, Tianyi; Bretones, Anaïs; Straume, Eivind Olavson; Nisancioglu, Kerim Hestnes & Gebbie, Geoffrey (2019). Cancellation of the precessional cycle in δ18O records during the Early Pleistocene. Full text in Research Archive Show summary

  Deep-sea δ18O records show a pronounced difference in Milankovitch periodicity between the Early and Late Pleistocene. δ18O is interpreted as a proxy for ice sheet volume and temperature, which led to the conclusion that glacial-interglacial cycles considerably changed their rhythm during the mid-Pleistocene. This transition is referred to as the mid-Pleistocene Transition (MPT). Specifically, the precessional component of the Milankovitch cycles is absent in Early Pleistocene δ18O records, despite its continuous presence in solar insolation forcing to the ice sheets. Climate feedbacks involving (sea) ice, geological processes and carbon and nutrient cycling have been proposed as causes of this marked change. We however show that the absence of an Early Pleistocene precession signal in deep-sea δ18O records could be the result of destructive interference of the precessional cycle in the interior ocean. Such cancellation is caused by the anti-phasing of the precessional cycle between the North Atlantic and Southern Ocean deep-water sources (see Figure). We explore the potential for cancellation in the transient setup of the Total Matrix Intercomparison model for a wide range of source signal strengths. Our results show that cancellation can cause the absence of the precessional signal due to cancellation in the interior South-Atlantic, Indian and Pacific basins. Cancellation is especially widespread for a relative end-member contribution typical for the Early Pleistocene. We therefore conclude that the precessional component is likely incompletely archived in Early Pleistocene δ18O records, and appears as an actual change in Milankovitch periodicity across the MPT. Proxies not susceptible to cancellation of precession (such as those currently retrieved across the MPT from Antarctica) would be able to verify to what extent deep-sea δ18O correctly represents Pleistocene climate.

• Straume, Eivind Olavson; Morée, Anne; Nisancioglu, Kerim Hestnes & Gebbie, Geoffrey (2019). Orbital Forcing of Climate and the Mid-Pleistocene Transition. Full text in Research Archive Show summary

  Climate archives, based on records of oxygen isotopes from marine sediments, show a pronounced change in the periodicity of the glacial cycles during the mid-Pleistocene (~1 million years ago). Before this time, and possibly from the initiation of major glaciations, the periodicity is dominated by the 41 kyr obliquity cycle of orbital insolation. However, in the past million years the ~21 and ~100 kyr cycles of precession and eccentricity have dominated the records of glacial cycles, and the records of atmospheric greenhouse gasses. This climate transition, the mid-Pleistocene Transition (MPT), is not fully understood. Nor are the dynamics of the glacial cycles. In this session we welcome contributions with perspectives on the MPT as well as the dynamics of the glacial cycles based on proxy records, theory and models. The topic is also timely in light of ongoing efforts to extract a continuous Antarctic ice core record spanning the MPT.

• Straume, Eivind Olavson; Gaina, Carmen & Medvedev, Sergei (2019). Cenozoic paleobathymetry of the Atlantic-Arctic oceanic gateways: Iceland plume pulsations and implications on paleo-ocean circulation. Full text in Research Archive
• Straume, Eivind Olavson; Gaina, Carmen & Medvedev, Sergei (2019). Cenozoic Paleobathymetry of the Northern Hemisphere Oceanic Gateways: Implications for Paleo-ocean Circulation and Climate. Full text in Research Archive
• Straume, Eivind Olavson (2018). Excursion, Diabasodden, Svalbard. Full text in Research Archive
• Straume, Eivind Olavson; Gaina, Carmen; Gjermundsen, Ada; Lacasce, Joseph Henry; Klocker, Andreas & Nikurashin, Maxim (2018). Global Miocene paleobathymetry: implications for paleo-ocean circulation. Full text in Research Archive
• Straume, Eivind Olavson (2017). Vulkanshow på Universitetsplassen i Oslo, i forbindelse med Forskningstorget 2017. Full text in Research Archive
• Straume, Eivind Olavson (2017). Jordas oppbygning, og hvordan platetektonikk og vulkanisme kan forårsake klimaendringer. Full text in Research Archive
• Straume, Eivind Olavson (2016). Jorda skifter ansikt: Tektonikk, vulkanisme og klimaendringer. Populærvitenskapelig foredrag i sammenheng med Ungforsk 2016. Full text in Research Archive
• Straume, Eivind Olavson (2016). Plakat og formidling ved Forskningstorget 2016. Full text in Research Archive

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