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| Titel |
Severe environmental effects of Chicxulub impact imply key role in end-Cretaceous mass extinction |
| VerfasserIn |
Julia Brugger, Georg Feulner, Stefan Petri |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250152341
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| Publikation (Nr.) |
 EGU/EGU2017-17167.pdf |
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| Zusammenfassung |
| 66 million years ago, during the most recent of the five severe mass extinctions in Earth’s
history, non-avian dinosaurs and many other organisms became extinct. The cause of this
end-Cretaceous mass extinction is seen in either flood-basalt eruptions or an asteroid impact.
Modeling the climatic changes after the Chicxulub asteroid impact allow to assess its
contribution to the extinction event and to analyze the short-term and long-term response of
the climate and the biosphere to the impact. Existing studies either investigated the effect of
dust, which is now believed to play a minor role, or used one-dimensional, non-coupled
models. In contrast, we use a coupled climate model to explore the longer lasting cooling
due to sulfate aerosols. Based on data from geophysical impact modeling, we set
up simulations with different stratospheric residence times for sulfate aerosols.
Depending on this residence time, global surface air temperature decreased by at
least 26∘C, with 3 to 16 years subfreezing temperatures and a recovery time larger
than 30 years. Vigorous ocean mixing, caused by the fast cooling of the surface
ocean, might have perturbed marine ecosystems by the upwelling of nutrients. The
dramatic climatic changes seen in our simulations imply severe environmental effects
and therefore a significant contribution of the impact in the end-Cretaceous mass
extinction. |
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