The asteroid that hit Earth 66 million years ago appears to have caused huge amounts of magma to spew out of the bottom of the ocean, a new study of seafloor data finds.
The discovery, described in the journal Science Advances, adds to the portrait of an extinction event that was as complex as it was deadly.
For decades, researchers have pointed to a cataclysmic asteroid smashing into the planet as the reason the dinosaurs, and many other species of life on Earth, were wiped out during what’s formally known as the Cretaceous-Paleogene extinction event (named for the periods that came before and followed after it). That impact, which scientists think left the roughly 110-mile-wide Chicxulub crater in the Gulf of Mexico, would have vaporized living things nearby and sent choking clouds of debris into the air, obscuring the sun.
But scientists have also pointed to another culprit: the Deccan Traps in present-day India, one of the largest volcanic provinces in the world, which just happened to be going gangbusters at the time of the extinction event. The ash and noxious gases from the Deccan Traps are really what killed the dinosaurs, some scientists say, downplaying the asteroid’s role.
“People still argue about which one was actually the primary driver of environmental changes that resulted in the death of dinosaurs,” said senior author Leif Karlstrom, an earth scientist at the University of Oregon in Eugene.
Researchers have also suggested that perhaps the two were connected — perhaps the asteroid triggered Deccan Trap volcanism, producing a brutal one-two punch that ultimately knocked out roughly three-quarters of the Earth’s plant and animal species. But recent work has shown that the traps started spewing roughly a quarter-million years before the asteroid hit, Karlstrom said.