Did a 3800-year-old Mw ∼9.5 earthquake trigger major social disruption in the Atacama Desert?

Early inhabitants along the hyperarid coastal Atacama Desert in northern Chile developed resilience strategies over 12,000 years, allowing these communities to effectively adapt to this extreme environment, including the impact of giant earthquakes and tsunamis. Here, we provide geoarchaeological evidence revealing a major tsunamigenic earthquake that severely affected prehistoric hunter-gatherer-fisher communities similar to 3800 years ago, causing an exceptional social disruption reflected in contemporary changes in archaeological sites and triggering resilient strategies along these coasts. Together with tsunami modeling results, we suggest that this event resulted from a similar to 1000-km-long megathrust rupture along the subduction contact of the Nazca and South American plates, highlighting the possibility of M-w similar to 9.5 tsunamigenic earthquakes in northern Chile, one of the major seismic gaps of the planet. This emphasizes the necessity to account for long temporal scales to better understand the variability, social effects, and human responses favoring resilience to socionatural disasters.

Automated summary

Early inhabitants in the Atacama Desert in northern Chile developed strategies to adapt to extreme environment, including earthquakes and tsunamis. Geoarchaeological evidence reveals a major tsunamigenic earthquake similar to 3800 years ago, suggesting the possibility of M-w similar to 9.5 tsunamigenic earthquakes in northern Chile.