Reference fram Continuity under the effects of great earthquakes?

GOMEZ, D; PIÑON, D; SMALLEY, R; LENZANO L

SANTIAGO

Simposio; National Geophysical Networks in Latin America.; 2015

Abstract: Several recent great earthquakes have produced regional to continental sized non-secular post-seismic deformation elds that are easilyresolvable with GPS, requiring further development of geodetic reference frame velocities to include these e-ects. The 2010, (Mw 8.8) Maule, Chile,earthquake produced a measurable, non-secular, post-seismic signal within latitudes 28°S to 40°S extending from the Pacic to the Atlantic. Usingcontinuous GPS (CGPS) data from the Red Argentina de Monitoreo Satelital Continuo and Central Andes GPS Project, we t an extended trajectory model(ETM) including secular South American plate velocity and boundary deformation, co-seismic discontinuity, and a non-secular, logarithmic post-seismictransient produced by the earthquake in the Posiciones Geodésicas Argentinas 2007 (POSGAR07) reference frame. We used least squares collocation(LSC) to model both the background secular inter-seismic and the non-secular post-seismic components of the ETM to predict movement of passivegeodetic benchmarks where continuous monitoring is not available. We tested the LSC model using campaign and CGPS data not used to generate themodel and found standard deviations (95% condence level) for the north and east components of 3.8 mm and 5.5 mm, respectively, indicating that themodel predicts the post-seismic deformation eld very well. Finally, we added a co-seismic displacement eld, estimated using an elastic nite elementmodel. The nal, trajectory prediction model ties the post-earthquake coordinates to POSGAR07 within 5 cm for ~91% of the passive test benchmarks