The entire mountainous region shown here is part of the Deccan Traps, showing the characteristic stair-like ridges of lava flows. This photo is from near the town of Mahabaleshwar. Credit: Loÿc Vanderkluysen

When an enormous asteroid struck Earth 66 million years ago, a planet-wide quake shook the magma plumbing of a massive, active volcano—radically changing the style of volcanic eruption in one of the planet’s rarest, largest lava flows. This is the sequence of events supported by a new study published last week in the Geological Society of America Bulletin by a team of scientists, including Drexel University volcanologist Loÿc Vanderkluysen and led by geologists at UC Berkeley.

Evidence for this colossal, catastrophic chain reaction came from geological features of a massive lava flow field in central-southern India known as the Deccan Traps. The lava that flowed there was so abundant that an area the size of Texas would have…