It is believed that more than 60 million years ago, an asteroid 10-kilometer in width hit our planet, leaving behind great chaos. This event is also associated with the mass death of non-flying dinosaurs, as well as 75 % of the living species of that time. Another major impact that some scientists think might have resulted from the asteroid is the triggering of fire storms that have supposedly also played a role in the extinction of the organisms of that era. The latter theory has received many arguments for and against it from different scientists.
The asteroid impact might have caused the ejection of hot melted rocks into the sky. Some purport that these stimulated wildfires when they were pulled back onto the surface of the Earth because of gravity; falling ejected rocks causing fires, is this possible, you ask?
While many maintain that the debris that rocketed into the sky later rained over the Earth causing fires because they were hot enough even when they fell down, scientist Claire Belcher from the University of Exeter has provided further insight into the subject by arguing that pieces of debris might have reached out of the atmosphere, thereby creating a protective shield that guarded the planet from extreme heat and fire. Those who are for the idea that the rocks did lead to massive fires indicate that charcoal imprints serving as geological evidence point to their theory being true.
Studies have been performed in the past, from both sides: some results supporting the theory, and others challenging it. For instance, a study done in support of it two years ago had as goal to analyse the theory. Computer models were designed to calculate the infrared radiation heat pulse the molten debris would cause when falling back into the atmosphere, and whether they really were able to cause global wildfires. Now, a new one, with lead author Claire Belcher, has tackled the question from another perspective.
The team of Claire Belcher combined computer simulations with real fires in their lab in an attempt to recreating some of the conditions like tremendous heat and energy that would result from the impact of the asteroid. They observed that the heat produced from that would be short-lived – lasting for only one minute. This was applicable for the regions in close proximity to the impact. However, the researchers also added that a more lasting released heat would have been felt beyond oceans, hot enough to trigger fires a great distance away.
Belcher stated: “This has shown us that the heat was more likely to severely affect ecosystems a long distance away, such that forests in New Zealand would have had more chance of suffering major wildfires than forests in North America that were close to the impact. This flips our understanding of the effects of the impact on its head and means that palaeontologists may need to look for new clues from fossils found a long way from the impact to better understand the mass extinction event.”
It is still unclear as to whether wildfires contributed to the extinction though.