Huaynaputina Eruption

In February 1600, the Huaynaputina volcano in southern Peru exploded in the largest volcanic eruption in the recorded history of South America. The blast devastated the surrounding region, and the ash and sulfur it threw into the atmosphere are widely linked to a sharp global cooling that followed. Many historians and climate scientists connect that cooling to the severe harvest failures of the early 1600s, including the Russian famine of 1601 to 1603. (The event's listing names the United States, but the volcano lies in Peru, in the Andes near the city of Arequipa.)

Huaynaputina was not an obvious mountain. It was a modest volcanic vent on the flank of a larger landform in the Andean volcanic belt, in a region that Spanish colonists had settled in the decades after the conquest of the Inca Empire. Local communities farmed the valleys, and Arequipa and nearby towns grew wine and grain. Few people at the time would have recognized the site as a major threat, and the volcano had little recorded history of eruption before 1600.

The eruption began in mid-February and built over several days, with powerful explosions, pyroclastic flows, and heavy ashfall. Spanish clergy and officials left accounts of darkness at midday, earthquakes, and ash falling over a wide area. Villages near the volcano were buried, and the ashfall and mudflows damaged farmland, killing livestock and crops. Estimates of the death toll vary, and the number is uncertain, but the loss of agriculture caused hardship across the region. Arequipa suffered heavily, and the economy of the wine-growing valleys was disrupted for years.

The global effects were just as notable. Sulfur gases formed fine aerosol particles in the stratosphere that reflected sunlight, and Northern Hemisphere summers in 1600 were among the coldest in centuries according to tree rings and other records. Frost and cold, wet weather damaged harvests in parts of Europe, Russia, and Asia. Evidence of the eruption has also been found in polar ice cores, which help scientists date and measure it.

In Russia, the cold contributed to the famine of 1601 to 1603, one of the worst in the country's history, which killed a large share of the population by many accounts and deepened the instability of the Time of Troubles. Historians caution that political and social factors also played a major role, so the volcano was likely one cause among several.

Today Huaynaputina is studied as a key example of how a single eruption can disrupt climate and societies far from its source, and it helps researchers gauge the risks from future large eruptions.