Princeton University researchers have developed a new model to more accurately simulate the seismic fallout from a meteorite striking the Earth. The model also reveals new information about the surface and interior of planets based on past collisions.
Researchers based in the laboratory of Princeton University Geologist Jeroen Tromp created the first model that takes into account the Earth’s elliptical shape, surface features and ocean depths in simulations of how seismic waves generated by a meteorite collision would spread across and within the planet. Previous projections relied on models using a featureless spherical world with nothing to disrupt the meteorite’s impact.
The research is detailed in the October issue of Geophysical Journal International. The researchers simulated the meteorite strike that caused the Chicxulub crater in Mexico, which had an impact 2 million times more powerful than a hydrogen bomb that many scientists believed triggered the mass extinction of dinosaurs 65 million years ago.
But the team’s rendering of the planet showed that the seismic waves caused by the meteorite would be scattered and unfocused, resulting in less severe ground displacement, tsunamis, and seismic and volcanic activity than scientists previously theorized.
Lead author Matthias Meschede of the University of Munich developed the model at Princeton through the university’s visiting student research collaborators program with co-authors Conor Myhrvold, and Tromp, who also is director of Princeton’s Institute for Computational Science and Engineering and a professor of applied and computational mathematics.
“We have developed the first model to account for how the Earth’s surface features and shape would influence the spread of seismic activity following a meteorite impact,” Meschede said in a news release about the research. “For the Earth, these calculations are usually made using a smooth, perfect sphere model, but we found that the surface features of a planet or a moon have a huge effect on the aftershock a large meteorite will have, so it’s extremely important to take those into account.”
After a meteorite impact, Meschede said seismic waves travel outward across the Earth’s surface like after a stone is thrown in water. These waves travel all the way around the globe and meet in a single point on the opposite side from the impact known as the antipode. The Princeton model shows that because the Earth is elliptical and its surface is heterogeneous, those waves travel with different speeds in different areas, changing where the waves end up on the other side of the world and the waves’ amplitude when they get there. These waves also are influenced by the interior.
“We can, in principle, now estimate how large a meteorite would have to have been to cause catastrophic events,” Meschede said.