The extinction of dinosaurs is popularly attributed to an asteroid that slammed into Earth 66 million years ago but while the impact may have indeed occurred, findings of a new study suggest it was not solely responsible for wiping out prehistoric species
The new study published in the journal Science on Thursday, Oct.1, suggests that the impact of a 6-mile wide asteroid at the Chicxulub crater in Mexico may have kicked off a period of volcanic activities and this combo of disasters drove the massive extinction.
The theory sounds feasible since earthquakes are known to induce volcanic eruptions. An impact of an enormous asteroid or comet would have produced a magnitude 11 earthquake on the Richter scale. The largest earthquake that occurred in 2014 has a magnitude of 8.2.
Study researcher Paul Renne, from Berkeley Geochronology Center, and colleagues went to Deccan Traps in India, which feature the long-solidified remnants of one of the biggest known volcanic eruptions in Earth's history.
There, the researchers sampled different levels of volcanic rock to get a glimpse of history and to look for evidence of any change that coincided with the impact of the asteroid.
"What we wanted to do was sample from the bottom of the pile, the middle of the pile and the top of the pile -- and try and determine where, within that whole sequence, the age of the impact and the extinction occurs," Renne said.
Volcanoes had already been erupting prior to the arrival of the asteroid but researchers have found a particular point when the pattern of the lava flows appeared to have dramatically changed and this was within 50,000 years of the impact.
"Based on our dating of the lavas, we can be pretty certain that the volcanism and the impact occurred within 50,000 years of the extinction, so it becomes somewhat artificial to distinguish between them as killing mechanisms: both phenomena were clearly at work at the same time," Renne said.
The findings suggest that the asteroid impact may have shaken up the Earth's plumbing system and set off volcanic events that also proved fatal to prehistoric life. The Deccan eruptions lasted for more than four centuries after the impact.
Together, the two events devastated the planet. Harmful fumes, dust and ashes were thrown into the air altering the climate and killing about 75 percent of all species in what is known as one of the worst extinctions on Earth.