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    • Cordilleran ice-sheet growth fueled primary productivity in the Gulf of Alaska, northeast Pacific Ocean 

      Müller, Juliane; Romero, Oscar; Cowan, Ellen A.; McClymont, Erin L.; Forwick, Matthias; Asahi, Hirofumi; März, Christian; Moy, Christopher M.; Suto, Itsuki; Mix, Alan; Stoner, Joseph (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-15)
      Fertilization of the ocean by eolian dust and icebergs is an effective mechanism to enhance primary productivity. In particular, high-nutrient, low-chlorophyll (HNLC) areas where phytoplankton growth is critically iron-limited, such as the subarctic Pacific Ocean and the Southern Ocean, are proposed to respond to increases in bioavailable Fe supply with enhanced phytoplankton productivity and carbon ...

    • Cyclostratigraphic age constraining for Quaternary sediments in the Makarov Basin of the western Arctic Ocean using manganese variability 

      Park, Kwangkyu; Kim, Jung-Hyun; Asahi, Hirofumi; Polyak, Leonid; Khim, Boo-Keun; Schreck, Michael; Niessen, Frank; Kong, Gee Soo; Nam, Seung-Il (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-26)
      The Quaternary paleoenvironmental history of the Arctic Ocean remains uncertain, mainly due to the limited chronological constraints, especially beyond the 14C dating limits of accelerator mass spectrometry (AMS). The difficulty in establishing reliable chronostratigraphies is mainly attributed to low sedimentation rates and diagenetic sediment changes, resulting in very poor preservation of ...

    • The FORCIS database: A global census of planktonic Foraminifera from ocean waters 

      Chaabane, Sonia; de Garidel-Thoron, Thibault; Giraud, Xavier; Schiebel, Ralf; Beaugrand, Grégory; Brummer, Geert-Jan; Casajus, Nicolas; Greco, Mattia; Grigoratou, Maria; Howa, Hélène; Ofstad, Siri; Jonkers, Lukas; Kucera, Michal; Kuroyanagi, Azumi; Meilland, Julie; Monteiro, Fanny; Mortyn, Graham; Almogi-Labin, Ahuva; Asahi, Hirofumi; Avnaim-Katav, Simona; Nassinot, Franck; Davis, Catherine V.; Field, David B.; Hernández-Almeida, Iván; Herut, Barak; Hosie, Graham; Howard, Will; Jentzen, Anna; Johns, David G.; Keigwin, Lloyd; Kitchener, John; Kohfeld, Karen E.; Lessa, Douglas V. O.; Manno, Clara; Marchant, Margarita; Ortiz, Joseph D.; Post, Alexandra; Rigual-Hernandez, Andres; Rillo, Marina C.; Robinson, Karen; Sagawa, Takuya; Sierro, Francisco; Takahashi, Kunio T.; Torfstein, Adi; Venancio, Igor; Yamasaki, Makoto; Ziveri, patrizia (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-03)
      Planktonic Foraminifera are unique paleo-environmental indicators through their excellent fossil record in ocean sediments. Their distribution and diversity are affected by different environmental factors including anthropogenically forced ocean and climate change. Until now, historical changes in their distribution have not been fully assessed at the global scale. Here we present the FORCIS ...

    • Late Quaternary paleoceanography of Vestnesa Ridge, Fram Strait: Ostracode species as a potential indicator of cold seep activity 

      Chu, Rachel W.C.; Yasuhara, Moriaki; Myrvang Riise, Karoline; Asahi, Hirofumi; Huang, Huai-Hsuan May; Cotton, Laura J.; Hong, Yuanyuan; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-02)
      Past intensity of methane release from deep-ocean methane hydrates continues to be challenging to reconstruct reliably. Here, we used fossil ostracode fauna paired with foraminiferal δ<sup>13</sup>C values in a marine sediment core from Vestnesa Ridge, western Svalbard margin, to reconstruct methane seepage activity during the late Quaternary and to examine faunal response to deglacial climatic ...