Evidence for ice-free summers in the late Miocene central Arctic Ocean
| Autor: | Jens Matthiessen, Frank Niessen, Ruediger Stein, Gregor Knorr, Michael Schreck, Wilfried Jokat, Kirsten Fahl, Achim J Kopf, Matthias Forwick, Laura Jensen, Gerrit Lohmann, Catalina Gebhardt, Michael A. Kaminski |
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| Rok vydání: | 2016 |
| Předmět: |
Alkenone
Multidisciplinary VDP::Mathematics and natural science: 400::Geosciences: 450 010504 meteorology & atmospheric sciences Science General Physics and Astronomy General Chemistry Biology Late Miocene 010502 geochemistry & geophysics 01 natural sciences General Biochemistry Genetics and Molecular Biology Seafloor spreading Proxy (climate) Article Summer season Oceanography Arctic 13. Climate action VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Sedimentary rock 0105 earth and related environmental sciences Submarine landslide |
| Zdroj: | EPIC3Nature Communications, 7, pp. 1-13 Nature Communications Nature Communications, Vol 7, Iss 1, Pp 1-13 (2016) |
| Popis: | Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth's climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger sediments from steep headwalls has led to exhumation of Miocene sediments close to the seafloor. Here we document the presence of IP25 as a proxy for spring sea-ice cover and alkenone-based summer sea-surface temperatures >4 °C that support a seasonal sea-ice cover with an ice-free summer season being predominant during the late Miocene in the central Arctic Ocean. A comparison of our proxy data with Miocene climate simulations seems to favour either relatively high late Miocene atmospheric CO2 concentrations and/or a weak sensitivity of the model to simulate the magnitude of high-latitude warming in a warmer than modern climate. Despite the importance of Arctic sea-ice in the global climate system, a paucity of pre-Quaternary sedimentary archives limits our understanding of its long-term history. Here, based on ancient sediments revealed by submarine landslides, the authors reconstruct Arctic sea-ice conditions during the Miocene. |
| Databáze: | OpenAIRE |
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