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La ruptura de las asperezas del terremoto obtenidas por detección acústica distribuida
Jiaxuan Li1, Taeho Kim2, Nadia Lapusta3,2
1Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA. jxli@caltech.edu.
Nature
|August 2, 2023
Resumen
Las matrices sísmicas de alta frecuencia revelan los detalles de la ruptura del terremoto. La detección acústica distribuida utilizando cables de fibra óptica captó las asperezas de las fallas, cruciales para comprender la dinámica de los terremotos.
Área de la Ciencia:
- Sismología
- Dinámica de la ruptura del terremoto
- La geofísica
Sus antecedentes:
- Las firmas de ruptura de terremotos de megathrust muestran dependencia de frecuencia, pero los radiadores de alta frecuencia son poco conocidos.
- Observar los radiadores de alta frecuencia en los terremotos de la corteza es un desafío sin densas matrices sísmicas.
Objetivo del estudio:
- Para obtener imágenes de radiadores de ruptura de terremotos de alta frecuencia utilizando detección acústica distribuida (DAS).
- Para investigar el papel de las asperezas de fallas en la modulación del comportamiento de ruptura de terremotos.
Principales métodos:
- Utilizó un cable de fibra óptica oscura de 100 kilómetros como una matriz sísmica de 10.000 canales.
- Se utiliza tecnología de detección acústica distribuida (DAS) para la adquisición de datos sísmicos de alta frecuencia.
- Se compararon los resultados de las imágenes con los datos de liberación de momento de largo período y las simulaciones de ruptura dinámica.
Principales resultados:
- Se obtuvieron exitosamente imágenes de cuatro subeventos de alta frecuencia para el terremoto Mw 6.0 del Valle del Antílope de 2021.
- Identificó estos subeventos como la ruptura de asperidades de fallas.
- Se ha demostrado que la ruptura por asperidad puede producirse en cascada y promover la propagación de la ruptura.
Conclusiones:
- Las asperidades de fallas modulan significativamente el comportamiento de ruptura de terremotos.
- La tecnología DAS proporciona un método novedoso para estudiar terremotos de tamaño moderado utilizando redes de fibra existentes.
- La integración con el modelado dinámico de ruptura puede mejorar la comprensión de los procesos de ruptura de terremotos.
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