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Activó periódicamente la sismicidad en el Monte Wrangell, Alaska, después del terremoto de Sumatra
Michael West1, John J Sánchez, Stephen R McNutt
1Alaska Volcano Observatory, Geophysical Institute, University of Alaska, Fairbanks, AK 99775, USA. west@gi.alaska.edu
Science (New York, N.Y.)
|May 21, 2005
Resumen
Las ondas superficiales de un terremoto lejano desencadenaron terremotos locales cerca del Monte Wrangell. Este enjambre sísmico ocurrió en fase con el movimiento de tierra de las ondas de Rayleigh, lo que sugiere una simple falla de cizallamiento en fallas normales.
Área de la Ciencia:
- Sismología Sismología Sismología.
- La geofísica es la geofísica.
- La tectónica es la tectónica.
Sus antecedentes:
- El terremoto de Sumatra de 2004 generó poderosas ondas superficiales.
- Las estaciones sísmicas cerca del Monte Wrangell proporcionaron datos cruciales.
Objetivo del estudio:
- Para investigar el desencadenamiento de terremotos locales por ondas superficiales distantes.
- Comprender la relación entre el movimiento de las ondas superficiales y la actividad sísmica local.
Principales métodos:
- Análisis de los datos sísmicos del Monte Wrangell.
- Correlación de la ocurrencia de terremotos locales con el desplazamiento de las ondas de Rayleigh.
- Cálculo de las tensiones extensionales horizontales.
Principales resultados:
- Un enjambre de terremotos de 11 minutos de 14 eventos locales se desencadenó cerca del Monte Wrangell.
- Los terremotos ocurrieron en fase con desplazamientos verticales positivos de las ondas de Rayleigh.
- El movimiento de onda de Rayleigh exhibió tensiones extensionales horizontales de hasta 25 kilopascales.
Conclusiones:
- Las ondas superficiales distantes pueden desencadenar terremotos locales.
- El mecanismo de activación implica una simple falla de cizallamiento en fallas normales.
- Las observaciones destacan la influencia de los eventos sísmicos a gran escala en la tectónica local.
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