After the Dinosaur-Killing Impact, Soot Played a Remarkable Role in Extinction
By Nola Taylor Redd/Smithsonianmag.com
The interstellar object (alternatively a comet or an asteroid) that killed the dinosaurs when it slammed into Earth didn’t work alone. Researchers have shown previously that its after-effects, such as tidal waves and earthquakes, played an important role in the mass extinctions of three-fourths of plant and animal life. Now, new research suggests that one of the most important factors was the soot-rich smoke from fires sparked by the collision.
Clay Tabor, a geoscientist at the University of Connecticut, and his colleagues studied soot, sulfates and dust to see how each type of particle may have contributed to the cataclysm. They found that while all three particles blocked heat from the sun, soot played a dominant role. The results were published earlier this year in the journal Geophysical Research Letters.
When the impactor plowed into the Earth and created the Chicxulub crater in Mexico, it vaporized the crust and created a planet-wide plume of debris that emitted radiation at a rate about 20 times stronger than the sun. It ignited plants and animals in its path. Later, lightning from impact-generated storms ignited more fires, maintaining an atmosphere rich in soot.
“Soot is very good at absorbing sunlight,” Tabor says. …read more: