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El flujo viscoelástico en la corteza inferior después del terremoto de 1992 en Landers, California
1Seismological Laboratory 252-21, California Institute of Technology, Pasadena, CA 91125, USA.
Science (New York, N.Y.)
|November 30, 1998
Resumen
La deformación postsísmica después del terremoto de Landers de 1992 fue modelada utilizando geodesia espacial. El flujo viscoelástico en la corteza inferior explica la deformación, ofreciendo información sobre los peligros de los terremotos y las estructuras de la cuenca y la cordillera.
Área de la Ciencia:
- La geofísica es la geofísica.
- La tectónica es la tectónica.
- Sismología Sismología Sismología.
Sus antecedentes:
- Se observó una deformación postsísmica a gran escala después del terremoto de Landers de 1992.
- Comprender la deformación postsísmica es crucial para la evaluación del peligro sísmico.
Objetivo del estudio:
- Para investigar los mecanismos que impulsan la deformación postsísmica después del terremoto de Landers de 1992.
- Para modelar las contribuciones del deslizamiento posterior y el flujo viscoelástico a la deformación observada.
Principales métodos:
- Se utilizaron datos de geodesia espacial para observar la deformación postsísmica a gran escala.
- Desarrolló modelos tridimensionales para simular procesos de deformación.
- Se estima la viscosidad de la capa inferior de la corteza.
Principales resultados:
- El deslizamiento posterior por sí solo no pudo explicar todos los desplazamientos horizontales y verticales observados.
- El flujo viscoelástico en una capa inferior de la corteza terrestre de aproximadamente 10 km de espesor explicó con éxito tanto la deformación postsísmica horizontal como la casi vertical.
- Se determinó que la viscosidad de esta capa débil es de aproximadamente 10^18 pascal-segundos.
Conclusiones:
- El flujo viscoelástico en la corteza inferior es el mecanismo dominante para el rebote postsísmico después de grandes terremotos.
- Este mecanismo puede explicar las estructuras extensionales en la provincia de Basin and Range.
- Los hallazgos tienen implicaciones para mejorar el análisis de riesgos sísmicos.
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