Analysis of Anisotropic Characteristics in the Valley of Mexico
Description:
We obtained preliminary results of an anisotropic seismic study based on the Shear Wave Splitting parameters from microearthquakes that occurred in and around the Valley of Mexico (VM), recorded by the Valley of Mexico Seismic Network from June 1996 until July 2023. These analyses focused on determining the effects of both local and regional tectonic stresses and deformation regimes from the behavior of common anisotropic alignments (e.g., faults, fractures, or cracks). In most cases, fast polarizations follow the orientation of already known local fault systems with preferential orientations of NE-SW, NNE-SSW, and E-W, along with other NW-SE fast polarizations that could show particular cases of unknown alignments in certain areas. Temporal variations of anisotropy could show deformations in the upper crust for specific regions due to changes in the tectonic environment and possible variations of pore-fluid pressure. Observations of splitting delays presented range mainly between 0.015 s to 0.07 s in most stations, with some individual values overpassing these values with important values of percentage of anisotropy, which can be considered systems bordering on critical fracturing systems. The areas with high values of anisotropy percentage (> 4.0%) allow for the characterization of the main fracture routes in the Valle of Mexico, which could be evidence of routes of internal deformation and important zones of ground motions.
Session: Anisotropy Across Scales [Poster Session]
Type: Poster
Date: 5/3/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Francisco
Student Presenter: Yes
Invited Presentation:
Authors
Francisco Chacón Presenting Author Corresponding Author fcochaconsalem@hotmail.com Universidad Nacional Autónoma de México |
Luis Quintanar-Robles luisq@igeofisica.unam.mx Universidad Nacional Autónoma de México |
Iván Rodríguez-Rasilla ivan@sismologico.unam.mx Universidad Nacional Autónoma de México |
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Analysis of Anisotropic Characteristics in the Valley of Mexico
Session
Anisotropy Across Scales