La anisotropía sísmica azimutal global y la deformación única del movimiento de la placa de Australia
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Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
Eric Debayle1, Brian Kennett, Keith Priestley
1Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre, Centre National de la Recherche Scientifique and Université Louis Pasteur, 61084 Strasbourg, Cedex, France. Eric.Debayle@eost.u-strasbg.fr
Nature
|February 4, 2005
Resumen
Las raíces continentales muestran una anisotropía sísmica variable. La placa australiana exhibe de manera única una fuerte anisotropía azimutal vinculada a su rápido movimiento, a diferencia de otros continentes con correlaciones más débiles.
Área de la Ciencia:
- La geofísica es la geofísica.
- Sismología Sismología Sismología.
- La tectónica de placas es la tectónica de placas.
Sus antecedentes:
- Debate sobre el origen de las "raíces" continentales debido a las variaciones en el grosor de la tapa de alta velocidad.
- La anisotropía radial observada a 250-300 km de profundidad sugiere la deformación actual en la base de las placas tectónicas.
- La anisotropía azimutal podría surgir de la alineación mineral debido a la deformación, con una variación azimutal significativa.
Objetivo del estudio:
- Investigar la anisotropía azimutal global de ondas superficiales para comprender la formación de raíces continentales.
- Determinar la relación entre la anisotropía azimutal, el movimiento de las placas y la profundidad debajo de los continentes.
- Identificar las regiones continentales con deformación significativa en la base de la placa.
Principales métodos:
- Tomografía sísmica global para obtener imágenes de estructuras subterráneas.
- Análisis de la anisotropía azimutal de las ondas superficiales.
- Correlación de los patrones de anisotropía con los datos actuales de movimiento de las placas.
Principales resultados:
- La placa continental australiana muestra una significativa anisotropía azimutal fuertemente correlacionada con su rápido movimiento de la placa (175-300 km de profundidad).
- Otros continentes exhiben una débil anisotropía azimutal, poco correlacionada con el movimiento de las placas y a profundidades similares a las placas oceánicas.
- La anisotropía azimutal debajo de otros continentes puede explicarse por un simple corte que conduce a la anisotropía con un eje de inmersión.
Conclusiones:
- La placa australiana es la única región continental con una deformación basal sustancial, creando una anisotropía azimutal observable.
- El movimiento de las placas y la deformación basal son factores clave para generar anisotropía azimutal en la litosfera continental.
- Las diferencias en la anisotropía azimutal proporcionan información sobre los procesos dinámicos que dan forma a las raíces continentales.
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