Analysis of Crustal Deformations Associated with Major Chilean Earthquakes of the Early 21st Century Using GNSS Observations

This study presents an analysis of the surface deformations along the Chilean coastline before and after a series of major earthquakes in the early 21st century. The planar strain-rate field was computed using Shen’s method applied to continuous GNSS observations from Chile and Argentina. Results reveal an increase in strain rates proximal to the earthquake sources during the preseismic period. Conversely, the postseismic period is characterized by a reduction in strain rates in the immediate vicinity of the rupture zones, indicative of progressive relaxation of accumulated crustal stresses. The earthquake sources are localized near regions exhibiting pronounced gradients in deformation-related field parameters, underscoring their association with zones of significant stress accumulation and redistribution within the crust.