Magnitude and impact of Ilopango volcanic eruption

Combining geological and archaeological evidence from central America with analysis of an ice core from Greenland, a study identifies the date of the Tierra Blanca Joven eruption to within 2 years of 431 CE. Large areas of El Salvador and its Maya sites show a layer of ash from the Tierra Blanca Joven eruption of the Ilopango volcano, which would have rendered areas within 80 km of the vent uninhabitable for decades during the Early Classic Period, around 300-600 CE. Pinpointing the date of the eruption can help clarify its impacts on climate and society. Victoria C. Smith, Antonio Costa, and colleagues combined archaeological evidence with analysis of ice cores in Greenland to date the eruption to within 2 years of 431 CE. Based on modeling of tephra deposition, the authors report that the eruption would have sent a 45 km plume into the atmosphere. The authors identified volcanic glass shards matching those from the eruption in a dated ice core from Greenland at 431 CE. Radiocarbon data from trees in the area of the eruption and sulfur spikes in Antarctic ice cores corresponded to the same time period. The authors note that the date also corresponds to archaeological records that suggest cessation of Maya ceramic production in El Salvador. According to the authors, the magnitude of the eruption would have cooled the atmosphere by 0.5 °C for a few years, and the major effects were largely limited to the local region.

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Article #20-03008: "The magnitude and impact of the 431 CE Tierra Blanca Joven eruption of Ilopango, El Salvador," by Victoria C. Smith et al.

MEDIA CONTACTS: Victoria C. Smith, University of Oxford, UNITED KINGDOM; e-mail: victoria.smith@arch.ox.ac.uk; Antonio Costa, Istituto Nazionale di Geofisica e Vulcanologia, Bologna, ITALY; e-mail: antonio.costa@ingv.it

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