A groundbreaking study has debunked the theory that the asteroid believed to have drove the dinosaurs extinct also caused massive firestorms that ravaged the planet.
Researchers from the Universities of Exeter, Edinburgh and Imperial College London have recreated the immense energy released by an extraterrestrial collision with Earth that took place around the time the dinosaurs became extinct. They found that the intense but brief heat near the impact site could not have scorched the plants, challenging the idea that the impact triggered firestorms globally.
These firestorms have previously been considered a major factor in the puzzle to discover what caused the mass extinction of life on Earth 65 million years ago.
The researchers found that near the impact site, a 200-kilometer crater in Mexico, the heat pulse - which would have lasted less than a minute - was too short to ignite living plant material. However, they found that the effects of the impact would have been felt as far away as New Zealand, where the heat would have been less intense but longer lasting - for about seven minutes - long enough to ignite plant matter.
The experiments were carried out in the laboratory and showed that dry plant matter could catch fire, but living plants, including green pine branches, generally would not have.
HEAT LASTED LONGER AT GREAT DISTANCES
Claire Belcher, of the Earth System Sciences in Geography group at LA, said: "By combining computer simulations of the impact with engineering methods, we have been able to recreate the enormous heat of the impact in the laboratory. This has shown us that the heat more likely affected ecosystems over a long distance, so New Zealand forests would have been more likely to experience major wildfires than North American forests near the impact. understanding the effects of the impact of this asteroid and means that paleontologists may have to search for new clues from fossils found far from the effects to better understand the mass extinction event. "
Plants and animals are generally resistant to localized fires - animals can hide and plants hibernate or recolonize from other areas, implying that it is unlikely that wildfires were directly capable of leading to extinction. If however, some animal communities, particularly large animals, were unable to shelter from the heat, they may have suffered severe losses. It is not clear if they would have been enough to drive them to extinction.