When the massive space rock that slammed into the Earth some 66 million years ago reached our planet it caused one heck of a scene. The effects of the impact were immediate, causing a massive explosion that sent water and rock flying as far as the eye could see. It dramatically changed the weather on a worldwide scale and plunged the planet into a cold, dark haze that led to the extinction of the majority of life. Now, scientists believe the incredible event may have also triggered countless underwater volcanoes to spontaneously spring to life, adding to the turmoil.

To get a better idea of exactly what was going on deep underwater at the time the meteorite struck, the researchers needed some way of measuring how the sea floor has changed over time. They used gravitational mapping tools from satellites to gather information that revealed when large deposits of material were made, and where that material piled up. What they found was a spike in the number of “structural anomalies” occurring immediately around when the rock is thought to have hit the planet.

Building upon the hard data, the researchers suggest that the force of the strike was enough to set off volcanic activity on the ocean floor, causing magma to gush from the mid-ocean ridges all over the world. The study, which was published in Science Advances, proposes that this period of heightened volcanic activity may have lasted for as long as hundreds of thousands of years.

“The total volume of excess material is difficult to pin down, because a large amount of magma could have been injected into the lower crust where it would have a weaker gravitational signature,” the researchers write. “But we estimate that around the time of the Chicxulub impact, on the order of 23,000 to 230,000 cubic miles of magma erupted out of the mid-ocean ridges, all over the globe.”

What is still unknown is just how the rapid increase of magma flow on the ocean floor impacted the plants and animals that call the oceans home. It’s impossible to say whether or not it would have been enough to cause extinction of oceanic creatures on a massive scale, or if the other effects of the strike (including changing climate) were the primary reason that so many aquatic creatures perished.