Did volcanoes help kill the dinosaurs?

[lpetrich]

Death of the dinosaurs: Extreme volcanism played pivotal role in extinction, research shows | Lawrence Livermore National Laboratory

Around the time of the extinction of the dinosaurs were massive volcanic eruptions that made the Deccan Traps in India. These eruptions were "flood basalt" ones that made a Large Igneous Province (LIP). There were four major pulses of eruption, and the biggest of them happened just before the extinction. So the combination of the eruptions and the asteroid strike is likely what did in the (non-avian) dinosaurs.

Volcanoes spew both sulfur dioxide, which cools the atmosphere on short timescales, and carbon dioxide, which warms the atmosphere on long timescales. Because the Deccan eruptions were pulsed, whenever an eruptive pulse occurred (for example, just before the Cretaceous-Paleogene boundary and extinction), it would likely have resulted in extreme short-term cooling, followed by long-term warming.

“Such dramatic shifts in atmospheric temperature can be catastrophic for delicately balanced ecosystems,” Samperton said. “Our data are strong evidence for highly nonlinear eruption rates over the volcanic province’s lifetime. This finding confirms what researchers have long suspected regarding the tempo of flood basalt eruptions, but until now had never had conclusive data for.”