Maya civilization was blossoming into its golden age when a volcano erupted at the southern edge of the Maya region, in what is now El Salvador. Tens of meters of ash and debris buried the densely populated, fertile farming valleys around the Ilopango caldera. Aerosols blasted into the stratosphere by the eruption settled as far away as Greenland and Antarctica. While the wider Maya civilization was mostly unaffected, it took a century and a half for life to resume in the shadow of Ilopango.

In a recent study, Oxford University archaeologist Victoria Smith and her colleagues used tree rings from a stump caught in a pyroclastic flow, along with data from polar ice cores obtained more than 7,000km (4,300 miles) away. These dated the eruption to 431 CE, the early part of the Maya Classic Period. The date may help future archaeologists and climate researchers better understand the impacts of the eruption on Central America and the rest of the world.

Buried by Tierra Blanca Joven

Volcanoes make dangerous neighbors, but they have ways of drawing people close despite the risks. Fertile volcanic soils in the valleys of El Salvador supported dense populations in Maya villages and urban centers like Chalchuapa. By the beginning of the Maya Classic Period, around 250 BCE, the rulers at Chalchuapa had built temples and a ball court at the site. Artifacts found among the ruins reveal trade connections as far away as central Mexico.