Large asteroids that slammed into Earth could have triggered ice age: Study

Our Earth has witnessed several “Snowball” periods during its history. During these periods, the entire planet remained covered in ice for thousands and even millions of years. For long, scientists have debated over one question: What could have triggered the initiation of the snowball periods? Now, a study has claimed that the process might have been triggered by large asteroids that slammed into Earth.

The study, published in the journal Science Advances, has been prepared by scientists from Yale, the University of Chicago and the University of Vienna.

Previous theory

According to one theory, the ice age might have begun due to a massive decline in greenhouse gases in the atmosphere. However, scientists still wanted to explore other possibilities.

Lead author of the study, Minmin Fu, the Richard Foster Flint Postdoctoral Fellow in the Department of Earth and Planetary Sciences in Yale’s Faculty of Arts and Sciences, said in a statement: “We decided to explore an alternative possibility.”

“What if an extraterrestrial impact caused this climate change transition very abruptly?” Minmin added.

How the study was conducted?

The scientists used a climate model and aligned it with characteristics of the aftermath of an asteroid strike in four different periods of the past: Preindustrial (150 years ago), Last Glacial Maximum (21,000 years ago), Cretaceous (145 to 66 million years ago), and Neoproterozoic (1 billion to 542 million years ago).

Scientists concluded that while the asteroid strike was unlikely to trigger a snowball in two warmer periods (Cretaceous and preindustrial), it could have triggered one in the other two periods as the temperature in climate was already low.

The temperature in the Glacial Maximum and Neoproterozoic periods was cold enough to set in motion an ice age.

“What surprised me most in our results is that, given sufficiently cold initial climate conditions, a ‘Snowball’ state after an asteroid impact can develop over the global ocean in a matter of just one decade,” said co-author Alexey Fedorov, a professor of ocean and atmospheric sciences in Yale’s Faculty of Arts and Sciences.

“By then the thickness of sea ice at the Equator would reach about 10 metres. This should be compared to a typical sea ice thickness of one to three metres in the modern Arctic.”

(With inputs from agencies)