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Visualization of Flow Field Around a Vibrating Pipeline Within an Equilibrium Scour Hole
Published on: August 26, 2019
La tomografía en forma de onda revela un flujo canalizado en la base de la astenosfera oceánica
Scott French1, Vedran Lekic, Barbara Romanowicz
1Berkeley Seismological Laboratory, Berkeley, CA 94720, USA.
Science (New York, N.Y.)
|September 7, 2013
Resumen
Los geofísicos descubrieron estructuras del manto profundo que influyen en la tectónica de placas y el vulcanismo de puntos calientes. Las zonas de baja velocidad casi periódicas, parecidas a dedos, se extienden por debajo de las placas tectónicas, lo que sugiere una afluencia de material del manto profundo.
Área de la Ciencia:
- La geofísica es la geofísica.
- Sismología Sismología.
- La tectónica de placas es la tectónica de placas.
- Dinámica del manto Dinámica del manto
Sus antecedentes:
- La relación entre las escalas de convección del manto y los fenómenos geológicos de superficie como el movimiento de las placas y el vulcanismo de puntos calientes sigue siendo poco comprendida.
- Los modelos existentes luchan por conciliar los procesos del manto profundo con la dinámica de placas poco profundas.
Objetivo del estudio:
- Para investigar las estructuras del manto profundo que impulsan los movimientos de las placas y el vulcanismo de los puntos calientes.
- Para comprender la interacción entre la dinámica del manto superficial y profunda.
Principales métodos:
- La tomografía sísmica de forma de onda completa se empleó para obtener imágenes de estructuras de velocidad de cizallamiento dentro del manto de la Tierra.
- El análisis se centró en la identificación de zonas de baja velocidad y su organización espacial a diversas profundidades.
Principales resultados:
- Se tomaron imágenes de bandas horizontales alargadas y cuasi periódicas de baja velocidad de corte (~ 2000 km de longitud de onda) entre 200-350 km de profundidad, alineadas con el movimiento absoluto de la placa.
- A menos de 400 km, se observaron menos columnas onduladas, verticalmente coherentes y de baja velocidad enraizadas en el manto inferior.
- Estas estructuras se extienden por debajo de la zona poco profunda de baja velocidad.
Conclusiones:
- Los hallazgos sugieren una interacción dinámica entre el flujo del manto impulsado por placas y el material ascendente de fuentes más profundas del manto.
- Las plumas del manto profundo parecen desviarse horizontalmente debajo de la litosfera en movimiento, lo que influye en la geología de la superficie.
- Esto proporciona nuevos conocimientos sobre los mecanismos que impulsan la tectónica de placas y la formación de puntos calientes.
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