“Reading” the shells: Daniel H. Sandweiss and the recasting of ENSO as a feature of coastal Peruvian environments

Abstract

Human-environment dynamics in coastal Peru are fundamentally tied to the El Niño Southern Oscillation (ENSO) phenomena. The El Niño phase of the ENSO cycle can manifest in multiple ways, including heavy rainfall and flash floods, overbank flooding along rivers, and mass death events among marine fauna, which archaeologists have hypothesized catalyzed socio-political shifts in the pre-Hispanic past. However, establishing secure archaeological sequences of human interaction with El Niño activity is a major obstacle to research. Daniel H. Sandweiss and colleagues’ holistic approach to mollusk analysis represented a seminal innovation in human-environment records. More importantly, their interdisciplinary work combining mollusk with geo- and archaeological records, arguably caused a phase-change in research around ENSO and El Niño in the pre-Hispanic past: while previous research focused on event magnitude as a driver of social change, Sandweiss’ approach to the long-term life cycle of ENSO, recast the El Niño phenomenon as a feature of the natural environment, opening the way to further complicate monocausal models and move toward multi-faceted interpretations of its role in society.