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| ww.space.com |
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| Space Science |
| Space Science |
| Space Science |
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| a s t r o n o m y w i t h t r u |
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| a s t r o n o m y w i t h t r u |
| WILDFIRE EFFECTS: |
| credits www.arizona/edu/ |
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| Space Science |
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| ww.space.com |
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| Large impact cratering events can produce wildfires over vast portions of the Earth's surface. In the case of the Chicxulub impact event that has been linked to dinosaur extinction, the wildfires affected vast portions of the world and sent plumes of smoke into that atmosphere that darkened the planet. Soot from the fires was carried by winds around the world and eventually settled to the ground where it accumulated on top of the debris that was ejected from the Chicxulub crater and also distributed globally. |
| These wildfires were devastating. Not only did they consume vegetation, they also destroyed important habitats and food resources for animals, possibly leading to the collapse of the food chain in continental regions. This and other impact-generated environmental effects led to the extinction of over 75% of the species. |
| The Evidence |
| The first evidence of these fires was found by Wendy Wolbach, Ed Anders, Roy Lewis, and Iain Gilmour at the University of Chicago. They found traces of the soot in the rocky remnants of the impact event that were scattered in places like Denmark, New Zealand, Spain, Turkmenia, and the United States, far from the point of impact in what is now Mexico. |
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| The fossil record also contains a biological signature of the wildfires. A detailed study by Tschudy and Chuck Pillmore with the U.S. Geological Survey discovered a fern-spore spike in the rock record. This is an anomolous concentration of the spores shed by growing ferns, relative to the pollen shed by other types of plants (e.g., angiosperms) that grew soon after the impact event. The anomalously high amount of fern spores indicates that ferns were the first large plants to regrow on the fire-ravaged landscape. Many years later, other plants, like flowering bushes and eventually trees, began to grow. |
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