• Active Nordic Seas deep-water formation during the last glacial maximum 

      Larkin, Christina S.; Mohamed, Mohamed Mahmoud Ezat Ahmed; Roberts, Natalie L.; Bauch, Henning A.; Spielhagen, Robert F.; Noormets, Riko; Polyak, Leonid; Moreton, Steven G.; Rasmussen, Tine Lander; Sarnthein, Michael; Tipper, Edward T.; Piotrowski, Alex M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-24)
      The Nordic Seas are the primary location where the warm waters of the North Atlantic Current densify to form North Atlantic Deep Water, which plays a key part in the modern Atlantic Meridional Overturning Circulation. The formation of dense water in the Nordic Seas and Arctic Ocean and resulting ocean circulation changes were probably driven by and contributed to the regional and global climate of ...
    • Brine formation in relation to climate changes and ice retreat during the last 15,000 years in Storfjorden, Svalbard, 76–78°N 

      Rasmussen, Tine Lander; Thomsen, Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-10-06)
      Storfjorden, Svalbard, is an area of intense brine formation. The brine is cold, dense, rich in oxygen and CO2, and has reduced pH. Storfjorden is unique because it contains well-preserved agglutinated foraminifera dating back to the beginning of the last deglaciation. We have investigated the distribution of calcareous and agglutinated benthic foraminifera, benthic oxygen and carbon isotopes, ...
    • Carbon isotope (d13C) excursions suggest times of major methane release during the last 14 ka in Fram Strait, the deep-water gateway to the Arctic 

      Consolaro, Chiara; Rasmussen, Tine Lander; Panieri, Giuliana; Mienert, Jurgen; Bünz, Stefan; Sztybor, Kamila (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Chemosynthetic and photosynthetic trophic support from cold seeps in Arctic benthic communities 

      Åström, Emmelie; Bluhm, Bodil; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-17)
      Benthic communities below the photic zone are largely reliant on the export of surface-water primary production and the flux of partially degraded organic matter to the seabed, i.e. pelagic−benthic coupling. Over the past decades, however, the role of chemosynthetically produced carbon in food webs has been recognized in various habitats. Cold seeps are now known to be widespread across circumpolar ...
    • Climate and ocean forcing of ice-sheet dynamics along the Svalbard-Barents Sea Ice Sheet during the deglaciation 20,000–10,000 years BP 

      Rasmussen, Tine Lander; Thomsen, Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-11)
      The last deglaciation, 20,000–10,000 years ago, was a period of global warming and rapidly shrinking ice sheets. It was also climatically unstable and retreats were interrupted by re-advances. Retreat rates and timing relative to climatic changes have therefore been difficult to establish. We here study a suite of 12 marine sediment cores from Storfjorden and Storfjorden Trough, Svalbard. The purpose ...
    • Cold-seep macrofaunal assemblages in cores from Vestnesa Ridge, eastern Fram Strait, during the past 45000 years 

      Thomsen, Elsebeth; Rasmussen, Tine Lander; Sztybor, Kamila; Hanken, Nils-Martin; Tendal, Ole Secher; Uchman, Alfred (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-22)
      Four cores from 1200 m water depth from Vestnesa Ridge on the western Svalbard margin in the eastern Fram Strait were studied for their content of fossil macro-faunas. Three of the cores were collected from a pockmark with active methane seepage, and one core (control core) was taken just outside the seepage area for comparison. Together the cores cover the last 45 000 years (mid-late Weichselian ...
    • Cold-seep ostracods from the western Svalbard margin: direct palaeo-indicator for methane seepage? 

      Yasuhara, Moriaki; Sztybor, Kamila; Rasmussen, Tine Lander; Okahashi, Hisayo; Sato, Runa; Tanaka, Hayato (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-05)
      Despite their high abundance and diversity, microfossil taxa adapted to a particular chemosynthetic environment have rarely been studied and are therefore poorly known. Here we report on an ostracod species, Rosaliella svalbardensis gen. et sp. nov., from a cold methane seep site at the western Svalbard margin, Fram Strait. The new species shows a distinct morphology, different from other ...
    • Contamination of 8.2 ka cold climate records by the Storegga tsunami in the Nordic Seas 

      Bondevik, Stein; Risebrobakken, Bjørg; Gibbons, Steven J.; Rasmussen, Tine Lander; Løvholt, Finn (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-04)
      The 8200-year BP cooling event is reconstructed in part from sediments in the Norwegian and North Seas. Here we show that these sediments have been reworked by the Storegga tsunami – dated to the coldest decades of the 8.2 ka event. We simulate the maximum tsunami flow velocity to be 2–5 m/s on the shelf offshore western Norway and in the shallower North Sea, and up to about 1 m/s down to a water ...
    • Decadal trend of plankton community change and habitat shoaling in the Arctic gateway recorded by planktonic foraminifera 

      Greco, Mattia; Werner, Kristin; Zamelczyk, Katarzyna; Rasmussen, Tine Lander; Kucera, Michal (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-16)
      The Fram Strait plays a crucial role in regulating the heat and sea-ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic species. The footprint of this ‘Atlantification’ has been identified in isolated observations across the plankton community, but a systematic, ...
    • Deep ocean 14C ventilation age reconstructions from the Arctic Mediterranean reassessed 

      Ezat, Mohamed; Rasmussen, Tine Lander; Skinner, Luke C.; Zamelczyk, Katarzyna (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-13)
      The present-day ocean ventilation in the Arctic Mediterranean (Nordic Seas and Arctic Ocean), via transformation of northward inflowing warm Atlantic surface water into cold deep water, affects regional climate, atmospheric circulation and carbon storage in the deep ocean. Here we study the glacial evolution of the Arctic Mediterranean circulation and its influence on glacial climate using ...
    • Deep ocean storage of heat and CO2 in the Fram Strait, Arctic Ocean during the last glacial period 

      Ezat, Mohamed; Rasmussen, Tine Lander; Hain, Mathis P.; Greaves, Mervyn; Rae, James W.B.; Zamelczyk, Katarzyna; Marchitto, Thomas M.; Szidat, Sönke; Skinner, Luke C. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-19)
      The Fram Strait is the only deep gateway between the Arctic Ocean and the Nordic Seas and thus is a key area to study past changes in ocean circulation and the marine carbon cycle. Here, we study deep ocean temperature, δ18O, carbonate chemistry (i.e., carbonate ion concentration [CO32−]), and nutrient content in the Fram Strait during the late glacial (35,000–19,000 years BP) and the Holocene based ...
    • Deglacial bottom water warming intensified Arctic methane seepage in the NW Barents Sea 

      El Bani Altuna, Naima; Rasmussen, Tine Lander; Ezat, Mohamed; Vadakkepuliyambatta, Sunil; Groeneveld, Jeroen; Greaves, Mervyn (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-09)
      Changes in the Arctic climate-ocean system can rapidly impact carbon cycling and cryosphere. Methane release from the seafloor has been widespread in the Barents Sea since the last deglaciation, being closely linked to changes in pressure and bottom water temperature. Here, we present a post-glacial bottom water temperature record (18,000–0 years before present) based on Mg/Ca in benthic foraminifera ...
    • Deglacial–Holocene Svalbard paleoceanography and evidence of Melt Water Pulse 1B 

      Tian, Skye Y.; Yasuhara, Moriaki; Hong, Y.; Huang, H.-H.; Iwatani, H.; Chiu, W.-T. R.; Mamo, Bryoni; Okahashi, Hisayo; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-09)
      Better understanding of deglacial meltwater pulses (MWPs) is imperative for future predictions of human-induced warming and abrupt sea-level change because of their potential for catastrophic damage. However, our knowledge of the second largest meltwater pulse MWP-1B that occurred shortly after the start of the Holocene interglacial remains very limited. Here, we studied fossil ostracods as ...
    • Development, productivity, and seasonality of living planktonic foraminiferal faunas and Limacina helicina in an area of intense methane seepage in the Barents Sea 

      Ofstad, Siri; Meilland, Julie; Zamelczyk, Katarzyna; Chierici, Melissa; Fransson, Agneta; Gründger, Friederike; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-09)
      Although the plankton communities in the Barents Sea have been intensely studied for decades, little is known about the living planktonic foraminiferal (LPF) and pteropod faunas, especially those found at methane seep sites. Along a repeated transect in the “crater area” (northern Barents Sea, 74.9°N, 27.7°E) in spring and summer 2016 the flux of LPF and of the pteropod species <i>Limacina helicina</i> ...
    • The effect of an experimental decrease in salinity on the viability of the subarctic planktonic foraminifera Neogloboquadrina incompta 

      Greco, Mattia; Meilland, Julie; Zamelczyk, Kasia; Rasmussen, Tine Lander; Kucera, Michal (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-27)
      Chemical signatures in the calcite of shells of polar and subpolar planktonic foraminifera have been frequently used to trace and quantify past meltwater discharge events. This approach assumes that the foraminifera can tolerate low salinity under extended periods. To obtain a first experimental constraint on salinity tolerance of Subarctic foraminifera, we carried out a culturing experiment with ...
    • Episodic release of CO2 from the high-latitude North Atlantic Ocean during the last 135 kyrs 

      Ezat, Mohamed; Rasmussen, Tine Lander; Honisch, Barbel; Groeneveld, Jeroen; DeMenocal, P. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-22)
      Antarctic ice cores document glacial-interglacial and millennial-scale variability in atmospheric pCO2 over the past 800 kyr. The ocean, as the largest active carbon reservoir on this timescale, is thought to have played a dominant role in these pCO2 fluctuations, but it remains unclear how and where in the ocean CO2 was stored during glaciations and released during (de)glacial millennial-scale ...
    • Fluid flow and methane occurrences in the Disko Bugt area offshore West Greenland: indications for gas hydrates? 

      Nielsen, Tove; Laier, Troels; Kuijpers, Antoon; Rasmussen, Tine Lander; Mikkelsen, Naja E.; Nørgård-Pedersen, Niels (Journal article; Tidsskriftartikkel, 2014-09-04)
      The present study is the first to directly address the issue of gas hydrates offshore West Greenland, where numerous occurrences of shallow hydrocarbons have been documented in the vicinity of Disko Bugt (Bay). Furthermore, decomposing gas hydrate has been implied to explain seabed features in this climate-sensitive area. The study is based on archive data and new (2011, 2012) shallow seismic and ...
    • Frenulate siboglinids at high Arctic methane seeps and insight into high latitude frenulate distribution 

      Sen, Arunima; Didriksen, Alena; Hourdez, Stephane; Svenning, Mette Marianne; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-09)
      Frenulate species were identified from a high Arctic methane seep area on Vestnesa Ridge, western Svalbard margin (79°N, Fram Strait) based on mitochondrial cytochrome oxidase subunit I (mtCOI). Two species were found: <i>Oligobrachia haakonmosbiensis</i>, and a new, distinct, and undescribed <i>Oligobrachia</i> species. The new species adds to the cryptic <i>Oligobrachia</i> species complex found ...
    • Glacial-interglacial sedimentation control on gas seepage exemplified by Vestnesa Ridge off NW Svalbard margin 

      Rasmussen, Tine Lander; Nielsen, Tove (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-08)
      Vestnesa Ridge is built-up of thick contourites mainly deposited during the last ∼5 million years. Methane leaks from deep gas reservoirs creating pockmarks on its crest, and which have been the focus of numerous studies. Sedimentation patterns in relation to the pronounced changes in oceanography and climate of the last glacial-interglacial cycles and its possible impact of seepage of gas have ...
    • Homogeneous glacial landscapes can have high local variability of strontium isotope signatures: Implications for prehistoric migration studies 

      Thomsen, Erik; Andreasen, Rasmus; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-15)
      Increasingly, strontium (Sr) isotopes are used to distinguish locals and migrants in prehistoric studies, by measuring <sup>87</sup>Sr/<sup>86</sup>Sr in human remains and comparing these values to the distribution of the bioavailable <sup>87</sup>Sr/<sup>86</sup>Sr in the study area, often in surface water. However, it has recently been shown that agricultural lime can have a substantial impact on ...