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La falla de la fuente del terremoto se encuentra debajo de Tokio
Hiroshi Sato1, Naoshi Hirata, Kazuki Koketsu
1Earthquake Research Institute (ERI), University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Science (New York, N.Y.)
|July 16, 2005
Resumen
Una falla de megatrust recientemente identificada debajo de Tokio, la placa del Mar de Filipinas.
Área de la Ciencia:
- La geofísica es la geofísica.
- Sismología Sismología.
- La tectónica es la tectónica.
Sus antecedentes:
- La región metropolitana de Tokio es susceptible a terremotos devastadores originados por una falla megatrust.
- Las estimaciones anteriores de la profundidad de la falla se basaban en la distribución de la sismicidad.
Objetivo del estudio:
- Para identificar la falla de megathrust subyacente a la región metropolitana de Tokio.
- Para determinar la profundidad y la geometría de esta falla.
- Para evaluar el impacto de la geometría de la falla en el análisis de riesgos sísmicos.
Principales métodos:
- Se empleó un perfil de reflexión sísmica profunda para identificar la falla.
- Análisis de datos sísmicos para determinar la profundidad y la geometría de las placas.
Principales resultados:
- La falla megatrust fue identificada como la superficie superior de la placa del Mar de Filipinas.
- La profundidad hasta la parte superior de la placa del mar de Filipinas oscila entre 4 y 26 kilómetros, menos profunda de lo estimado anteriormente.
- La geometría de la placa revisada altera la ubicación del deslizamiento finito máximo para el terremoto de Kanto de 1923.
Conclusiones:
- La geometría poco profunda de la placa del mar de Filipinas tiene un impacto significativo en las evaluaciones de riesgos sísmicos en la región de Tokio.
- La comprensión actualizada de la profundidad de la falla es crucial para las estimaciones precisas de movimiento de tierra fuerte.
- Este hallazgo requiere una reevaluación de los modelos de riesgo sísmico para Tokio.
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