The widely-accepted theory that the Chicxulub impact led to a mass extinction event 66 million years ago now includes a new facet—micrometric silicate dust might have triggered a global cooling of 15°C. A recent study from the Royal Observatory of Belgium posits that such dust could have inhibited photosynthesis for nearly two years, significantly contributing to the widespread extinction.
Microscopic dust particles formed from the disintegration of rock due to the Chicxulub impact appear to have been the principal agents behind the global climatic cooling and the interruption of photosynthesis, as indicated by new research published in Nature Geoscience. Researchers Cem Berk Cenel, Özgür Karatekin, and Orkun Temel from the Royal Observatory of Belgium were key contributors to this study.
For a long time, the Chicxulub impact has been considered the catalyst for a worldwide impact winter, resulting in the extinction of dinosaurs and approximately 75% of Earth’s species during the Cretaceous-Palaeogene boundary 66 million years ago. However, the specific climatic effects of the different kinds of debris ejected from the crater are still a matter of scientific debate, leaving the exact cause of the mass extinction ambiguous.
Previous studies had emphasized sulfur emissions and post-impact wildfire soot as the primary causes of the impact winter, sidelining the role of silicate dust. These earlier hypotheses were largely formulated based on limited data concerning the size properties of these dust particles.
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New Perspectives from the Royal Observatory of Belgium
To understand the individual contributions of sulfur, soot, and silicate dust to post-impact climate alterations, scientists Cem Berk Senel, Orkun Temel, and Özgür Karatekin from the Royal Observatory of Belgium developed a novel paleoclimate model. The model was specialized to simulate the climate and biological responses in the aftermath of the Chicxulub impact, incorporating new high-resolution geological field data from a location in North Dakota, USA.
Sediment samples for this study were analyzed using laser-diffraction grain-size techniques by Pim Kaskes and associates at the Vrije Universiteit Brussel and Vrije Universiteit Amsterdam. Kaskes elaborated, “The data demonstrate much finer grain-size values than were previously used in climate models, which has significant implications for our climate reconstructions.”
Understanding the Role of Silicate Particles
Subsequent analysis found that the size distribution of silicate debris ranged between approximately 0.8–8.0 µm, suggesting a larger role for fine dust than previously assumed. According to Cem Berk Senel, the lead author, “Our new paleoclimate simulations indicate that this fine silicate dust could have persisted in the atmosphere for up to 15 years, leading to a global surface cooling of up to 15°C immediately following the impact.”
Co-authors Steven Goderis and Philippe Claeys indicated that this timescale aligns well with recent global observations concerning the layer of iridium in the Chicxulub impact structure, suggesting the final settling of fine-grained material occurred in less than 20 years.
Furthermore, the study finds that the changes in solar irradiance induced by this dust could have terminated photosynthesis for nearly two years. This extended disruption could have posed existential challenges for terrestrial and marine habitats, leading to mass extinctions.
Broader Implications and Planetary Defense Strategies
Özgür Karatekin pointed out that while Chicxulub-scale impacts are rare, smaller asteroids are far more common and could potentially cause regional or national devastation. Contributions to the European Space Agency’s Hera mission for planetary defense from authors of this study aim to improve our understanding of asteroid impacts and potential mitigation strategies.
Funding and Acknowledgments
This research received funding from the Belgian Federal Science Policy and is part of the Chicxulub BRAIN-be project, a collaborative endeavor involving the Royal Observatory of Belgium, Vrije Universiteit Brussel, and the Royal Belgian Institute of Natural Sciences. Additional financial support was provided through Research Foundation-Flanders grants and a FED-tWIN project.
Reference: “Chicxulub impact winter sustained by fine silicate dust” by Cem Berk Senel, Pim Kaskes, Orkun Temel, Johan Vellekoop, Steven Goderis, Robert DePalma, Maarten A. Prins, Philippe Claeys, and Özgür Karatekin, published on 30 October 2023 in Nature Geoscience. DOI: 10.1038/s41561-023-01290-4
Frequently Asked Questions (FAQs) about Chicxulub impact
What is the main focus of the new research from the Royal Observatory of Belgium?
The primary focus of the new study is to investigate the role of micrometric silicate dust in the aftermath of the Chicxulub impact that occurred 66 million years ago. The research suggests that this dust could have caused a global cooling of 15°C and disrupted photosynthesis for almost two years, contributing to the mass extinction event.
What was the previous understanding of what caused the impact winter?
Prior to this research, it was widely believed that sulfur and soot from post-impact wildfires were the main drivers of the impact winter. The ejection of silicate dust into the atmosphere was not considered to be as significant.
How did the scientists carry out their research?
The scientists developed a new paleoclimate model specialized to simulate the climate and biotic response following the Chicxulub impact. They incorporated high-resolution geological field data from a location in North Dakota, USA, and used laser-diffraction grain-size analysis for sediment samples.
What were the major findings concerning the role of silicate dust?
The research found that micrometric silicate dust could have remained in the atmosphere for up to 15 years, contributing to a 15°C global cooling. This would have disrupted photosynthesis for almost two years, posing severe challenges for both terrestrial and marine habitats.
How does this new research align with paleontological records?
The findings are consistent with paleontological records which show that species capable of entering a dormant phase (e.g., through seeds, cysts, or hibernation in burrows) and adapting to an omnivorous diet were more likely to survive the mass extinction event.
What are the implications for planetary defense?
The research contributes to our understanding of the potential consequences of asteroid impacts, which is vital for planetary defense strategies. It specifically informs the European Space Agency’s Hera asteroid mission aimed at validating asteroid deflection techniques.
Who funded the research?
The research was supported by Belgian Federal Science Policy (BELSPO) through the Chicxulub BRAIN-be project. It was a collaborative effort involving the Royal Observatory of Belgium, Vrije Universiteit Brussel, and the Royal Belgian Institute of Natural Sciences. Additional funding came from Research Foundation-Flanders (FWO) grants and a FED-tWIN project.
More about Chicxulub impact
- Royal Observatory of Belgium Research Overview
- Nature Geoscience Journal Article
- European Space Agency’s Hera Mission
- Vrije Universiteit Brussel Research
- Belgian Federal Science Policy (BELSPO)
- Research Foundation-Flanders (FWO)
- Paleoclimate Modeling Techniques
- Cretaceous-Paleogene Extinction Event
- Chicxulub Crater Geological Data
10 comments
Those paleoclimate models must be insanely complex. Kudos to the scientists for piecing this puzzle together.
It’s kinda scary to think how a single event can disrupt photosynthesis and basically set off a chain reaction that leads to mass extinction.
This research opens up new questions too. Like, could similar events have caused other extinctions we don’t know about? Makes you wonder.
so the dinos could’ve survived a nuclear winter but not this? Man, nature is brutal.
Wow, who would’ve thought silicate dust could have such a big impact! Really opens your eyes on how delicate our ecosystem really is.
What’s interesting is how this research also has implications for planetary defense. Like, this isn’t just about the past, it’s about our future too.
Always thought it was the volcanoes that did them in. This is an eye-opener for sure.
This is groundbreaking stuff. I mean, 15 degrees of global cooling just from dust? That’s nuts.
The research methods are so advanced now, using laser-diffraction and all. Science has come a long way.
High-res geological data and laser diffraction? Science at its best folks.