Seismic Activity in Central Chile: The March 2010 Magnitude 7.0 Earthquake Near Santa Cruz

On March 11, 2010, at 14:55 local time, a magnitude 7.0 earthquake struck 52 km northwest of Santa Cruz, Chile, at a depth of 18 km. This event occurred in a region of intense tectonic activity and formed part of the aftershock sequence following the devastating February 27, 2010, Maule earthquake. Central Chile lies along the convergent boundary where the Nazca Plate subducts beneath the South American Plate at rates of approximately 6–7 cm per year. This subduction zone generates frequent megathrust earthquakes and associated aftershocks. The March 11 event originated within the shallow portion of the plate interface, consistent with typical depths for interplate seismicity in the area. The O’Higgins and Maule regions have a long record of destructive earthquakes. Notable historical events include the 1575 and 1730 Valparaíso earthquakes, as well as the 1960 Valdivia earthquake, the largest instrumentally recorded event worldwide. These quakes demonstrate the persistent seismic hazard posed by the subduction zone. The 2010 Maule mainshock released strain accumulated over more than a century, producing widespread surface deformation and triggering thousands of aftershocks. The magnitude 7.0 event on March 11 was among the larger aftershocks, occurring within the rupture zone and highlighting ongoing stress adjustment along the fault. Modern seismic monitoring by Chilean and international networks provides high-resolution data on regional seismicity. Updated catalogs confirm continued moderate aftershock activity in the years following 2010, underscoring the need for resilient infrastructure and preparedness in this tectonically active corridor.

• USGS Earthquake Catalog
• Servicio Nacional de Geología y Minería (SERNAGEOMIN) reports
• International Seismological Centre (ISC) bulletins