Volcanic activity generally does one of two things: it gives life, and takes life away. People are more familiar with the latter concept, and there are plenty of volcanic eruptions around the world that have lived up to this reputation. Vesuvius’s destruction of Pompeii and Herculaneum is perhaps the most well-known example, but lest we forget, volcanoes have sometimes ended entire civilizations: Santorini’s cataclysmic eruption wiped out the Minoans 3,650 years ago.

New research outlined at the annual gathering of the European Geosciences Union (EGU) in Vienna pinpoints another civilization-disrupting – if not destroying – volcanic eruption. Based on a range of samples of ancient volcanic ash, a gigantic explosion at El Chichón, a vast lava dome in Mexico, may have plunged the Central American Mayan civilization into chaos in the 6th century.

“The thickness of the local deposits indicate that this was a large eruption,” Kees Nooren, the study’s lead author and a PhD candidate at Utrecht University in the Netherlands, told BBC News. “We would expect that it was directed towards the Mayan lowlands.”

El Chichón is best known to those in the region for its devastating 1982 eruption. After the lava dome’s peak collapsed, huge pyroclastic flows surged out and down the flanks of the volcano, burying nine villages and killing 1,900 people.

Far from just quickly consuming people, this volcanic eruption’s destructiveness continued long after the main act had subsided. 24,000 square kilometers (9,270 square miles) of the surrounding landscape experienced significant ash fallout, which ruined swaths of coffee, cocoa, and banana crops.

^{El Chichón, seen two months after its horrific 1982 eruption. USGS}

As disruptive as this was, this new research reveals that a far more severe eruption may have coincided with the “hiatus” in the once-great Mayan civilization, several decades within the 6th century wherein many settlements were abandoned, their cultural output began to significantly falter, and there was clear political instability. Volcanic activity has been suggested before as a potential cause of this hiatus, but this particular team of researchers think that they’ve finally found strong evidence for this.

When volcanoes erupt, they spurt out vast quantities of sulfur as a fine aerosol. Sulfur found as far as ice in the North and South Poles indicates that there was a pretty huge eruption somewhere on Earth in the year 540, which happens to mark the very beginning of the Mayan hiatus.

Chemically, these distant ash deposits can be linked back to the very specific magma found beneath El Chichón. Dating of volcanic ash found in Mexico confirms that an eruption at El Chichón took place in 540.

The level of sulfur found in the ice cores suggests that the eruption was powerful enough to darken the sky and cause a small period of sudden regional cooling. The thickness of the Mexican ash deposits also indicates that surrounding environment would have been coated in suffocating ash.

A separate study notes that the polar sulfur signatures could also be linked to a second eruption, perhaps in Alaska, which occurred in the year 536. When combined with the El Chichon eruption, the Mayans would have experienced nothing short of a mini-apocalypse, with sulfur aerosols effectively cancelling a succession of warmer summers, and ash fallout majorly disrupting their agriculture and burying their settlements.

Volcanic activity may have been to blame for the Mayan hiatus, then, but the reasons for the civilization’s ultimate downfall remain debatable.