Repeated settlement abandonment and relocation in the Upper Colca Region (Peru): An archaeoseismological perspective

In this study, archaeoseismological methods and seismic modeling were employed to explore the influence of earthquakes on community relocations in the Colca Region, Peru, over the past 500 years. Observed structural damage and anomalies suggest that localized shallow earthquakes may have contributed to the abandonment of some settlements. The desertion of Malata was politically motivated, with no seismic damage observed before its abandonment, as corroborated by historical records. The reason for the relocation from Laiqa Laiqa to Mawchu Llacta appears problematic, as political, logistical, and potentially seismic factors are equally plausible. At Mawchu Llacta, archaeoseismological features such as tilted walls, collapsed towers, and oversized buttresses indicate cumulative seismic damage from multiple events over 250 years, ultimately prompting the community's relocation to modern-day Tuti. Similar seismic impacts, including U-shaped wall collapses and structural tilting, are evident in Tuti's present-day church, reflecting the effects of seismic activity over the last 150 years. From a broader perspective, this study demonstrates the potential of integrating archaeoseismology with seismic modeling to advance scientific approaches to investigating archaeological evidence, particularly in contexts with limited temporal resolution. A key outcome is that severe archaeoseismological damage does not necessarily reflect a single catastrophic earthquake, but may instead result from the cumulative effects of repeated moderate-to-minor seismic events over extended periods. This finding has important implications for reconstructing past seismic intensities from archaeological records, as accumulated damage in regions of persistent seismic activity may lead to systematic overestimation of individual earthquake intensities.