Ciencias de la Tierra Sólida
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Esta comunidad incluye estudios en geofísica, geología, geotecnica, sismología, geodinámica y vulcanología.
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Browsing Ciencias de la Tierra Sólida by Author "Ampuero, Jean‐Paul"
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Item Restricted Bayesian parameter estimation for space and time interacting earthquake rupture model using historical and physics-based simulated earthquake catalogs(Seismological Society of America, 2021-12) Ceferino, Luis; Galvez, Percy; Ampuero, Jean‐Paul; Kiremidjian, Anne; Deierlein, Gregory; Villegas Lanza, Juan CarlosThis article introduces a framework to supplement short historical catalogs with synthetic catalogs and determine large earthquakes’ recurrence. For this assessment, we developed a parameter estimation technique for a probabilistic earthquake occurrence model that captures time and space interactions between large mainshocks. The technique is based on a two‐step Bayesian update that uses a synthetic catalog from physics‐based simulations for initial parameter estimation and then the historical catalog for further calibration, fully characterizing parameter uncertainty. The article also provides a formulation to combine multiple synthetic catalogs according to their likelihood of representing empirical earthquake stress drops and Global Positioning System‐inferred interseismic coupling. We applied this technique to analyze large‐magnitude earthquakes’ recurrence along 650 km of the subduction fault’s interface located offshore Lima, Peru. We built nine 2000 yr long synthetic catalogs using quasi‐dynamic earthquake cycle simulations based on the rate‐and‐state friction law to supplement the 450 yr long historical catalog. When the synthetic catalogs are combined with the historical catalog without propagating their uncertainty, we found average relative reductions larger than 90% in the recurrence parameters’ uncertainty. When we propagated the physics‐based simulations’ uncertainty to the posterior, the reductions in uncertainty decreased to 60%–70%. In two Bayesian assessments, we then show that using synthetic catalogs results in higher parameter uncertainty reductions than using only the historical catalog (69% vs. 60% and 83% vs. 80%), demonstrating that synthetic catalogs can be effectively combined with historical data, especially in tectonic regions with short historical catalogs. Finally, we show the implications of these results for time‐dependent seismic hazard.Item Restricted Implementation of the Peruvian Earthquake Early Warning System(GeoScienceWorld, 2024-12-20) Lara, Pablo; Tavera, Hernando; Bletery, Quentin; Ampuero, Jean‐Paul; Inza Callupe, Lamberto Adolfo; Portugal, David; Orihuela, Benazir; Meza, FernandoWe present the implementation and testing of the seismological components of the Peruvian earthquake early warning system (Sistema de Alerta Sísmica Peruano [SASPe]). SASPe is designed to send alert messages to areas located within a given distance from the epicenter of large (magnitude ≥6.0) subduction earthquakes, with a first alert based on data available 3 s after the arrival of the P wave on the nearest station. The system comprises a dedicated network of 111 strong motion stations installed along the Peruvian coast. During over 2 yr of testing, the magnitude estimates are virtually unbiased, with no false positives or false negatives. In the most critical virtual scenarios of earthquakes occurring within 57 km of populated areas, SASPe can provide user lead times of up to 8 s. For more distant areas (from 70 to 120 km), lead times range from 10 to 20 s. Once the construction of the alert broadcasting system by the civil defense authority is finalized, SASPe will provide warning to 18 million residents of the coast of Peru. We validate the algorithm of the system on recent major earthquakes in Peru and other regions, demonstrating its effectiveness and versatility for global deployment.