Holocene Earthquakes on the Tambomachay Fault near Cusco, Central Andes

Research reveals that the Tambomachay Fault near Cusco, Peru, has experienced multiple Holocene earthquakes with significant seismic activity. Analysis of fault scarps and moraine crests indicates a mean throw of 4.3 ± 0.4 meters, with cosmogenic surface-exposure dating suggesting a Holocene-average slip rate of 0.3 ± 0.1 mm/yr. Trench excavations combined with radiocarbon dating identified three surface-rupturing earthquakes occurring between 8.5 and 0.9 ka, all predating Inca times. These events likely had moment magnitudes of Mw 6.4-6.9, posing a substantial seismic hazard to modern-day Cusco, which has a population of 500,000.

Rosell, L. (2023). Holocene Earthquakes on the Tambomachay Fault near Cusco, Central Andes. Tektonika, 1(2). https://doi.org/10.55575/tektonika2023.1.2.27