EGU22-604, updated on 10 Jan 2024
https://doi.org/10.5194/egusphere-egu22-604
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Deterministic scenarios for seismic hazard assessment in the metropolitan area of San Jose, Costa Rica. First results of the Kuk-Ahpan Project.

Adriana Fatima Ornelas Agrela1, Belen Benito Oterino1, Rebeca Franco Blanco1, Carlos García Lanchares1, Miguel Marchamalo Sacristan2, Guillermo Alvarado3, Alvaro Climent4, Walter Montero5, and Victor Schmidt5
Adriana Fatima Ornelas Agrela et al.
  • 1Escuela Técnica Superior de Ingenieros en Topografía Geodesia y Cartografía, Universidad Politécnica de Madrid, España (af.ornelas@alumnos.upm.es)
  • 2Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, España.
  • 3Comisión Nacional de Prevención de Riesgos y Atención de Emergencias (CNE), Unidad de Investigación y Análisis del Riesgo, San José, Costa Rica.
  • 4Red Sismológica Nacional (RSN), San José, Costa Rica.
  • 5Universidad de Costa Rica (UCR), San José, Costa Rica.

We present here the first results of the KUK-AHPAN Project: INTEGRATED REGIONAL STUDY OF STRUCTURE AND EVOLUTION 4D OF CENTRAL AMERICAN LITHOSPHERE. IMPLICATIONS IN SEISMIC HAZARD AND RISK CALCULATION). One of the main purposes of this project is to improve the knowledge of the seismic hazard in Central American countries, as well as the seismic risk in populations of the region.

An initial phase is addressed to define deterministic scenarios in the capital cities, giving the expected strong motion due to possible ruptures in local faults which may be critical for the risk of the population.

Preliminary results have already been found in the metropolitan area of San Jose (Costa Rica), affected by moderate-high seismicity due to a complex system of faults in the Valle Central in a local frame. In a regional context, the seismicity of the country is explained by the tectonic interaction between the Cocos and Caribbean plates.

We have identified three critical scenarios corresponding to events located in the Belo Horizonte, Rio Azul, and Cipreses faults. The strong motion for these scenarios has been estimated firstly in rock conditions, by application of different Ground Motion Prediction Equations. (GMPEs). In the second place, a microzonation map for San Jose is proposed, derived from data of isoperiods, lithology and other geotechnical information.  The amplification factor for the different soils has been extracted from NEHRP. Finally, we estimated the peak ground acceleration (PGA) and other spectral accelerations SA(T) including the local effects for each rupture scenario defined.

These deterministic scenarios will be compared with other results obtained with probabilistic approaches including modelization of faults in the definition of source models. A final goal is to improve the knowledge of the influence of the source models based on faults, not only in zones, in the hazard estimates.

How to cite: Ornelas Agrela, A. F., Benito Oterino, B., Franco Blanco, R., García Lanchares, C., Marchamalo Sacristan, M., Alvarado, G., Climent, A., Montero, W., and Schmidt, V.: Deterministic scenarios for seismic hazard assessment in the metropolitan area of San Jose, Costa Rica. First results of the Kuk-Ahpan Project., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-604, https://doi.org/10.5194/egusphere-egu22-604, 2022.