Submarine landslides: the seafloor in motion
3 pages, 2 figures [EN] On 18 November 1929, a magnitude 7.2 earthquake occurred south of Newfoundland, causing widespread failure of the seafloor. The underwater landslide involved more than 150 km3 of sediment (approximately 100 times the annual container traffic of Shanghai’s port, the world’s la...
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| Format: | Book Part |
| Language: | English |
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Consejo Superior de Investigaciones Científicas (España)
2022
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| Online Access: | http://hdl.handle.net/10261/255567 https://doi.org/10.20350/digitalCSIC/14103 |
| Summary: | 3 pages, 2 figures [EN] On 18 November 1929, a magnitude 7.2 earthquake occurred south of Newfoundland, causing widespread failure of the seafloor. The underwater landslide involved more than 150 km3 of sediment (approximately 100 times the annual container traffic of Shanghai’s port, the world’s largest) and evolved into a turbidity current that travelled over the seafloor for about 16 h, breaking several submarine cables along its path (Heezen and Ewing 1952). The cables broke almost instantaneously near the epicentre and at increasing times downslope, accidentally providing the first record of the dynamic history of a submarine landslide. Average peak velocities between cable breaks exceeded 20 m/s (72 km/h). Such a large volume of sediment rapidly accelerating underwater created a tsunami that was recorded across the Atlantic, with tsunami waves of up to 7.5 m in Newfoundland, where property damage was severe and 28 fatalities occurred (Government of Canada n.d.). […] [ES] El 18 de noviembre de 1929 se produjo un terremoto de 7,2 Mw al sur de Terranova, que provocó la rotura generalizada del fondo marino y provocó un desprendimiento submarino. El desprendimiento afectó a más de 150 km3 de sedimentos (~100 veces el tráfico anual de contenedores del puerto de Shanghai, el mayor del mundo) y se convirtió en una corriente de turbidez que recorrió el fondo marino durante unas 16 horas rompiendo varios cables submarinos a su paso (Heezen y Ewing 1952). Los cables se rompieron casi instantáneamente cerca del epicentro y en tiempos crecientes ladera abajo, proporcionando accidentalmente el primer registro histórico de la dinámica de un deslizamiento submarino. Las velocidades máximas medias del deslizamiento entre roturas de los cables superaron los 20 m s–1 (72 km h–1). Un volumen tan grande de sedimentos que se aceleró de manera tan rápida bajo el agua creó un tsunami que se registró en todo el Atlántico con olas de hasta 7,5 m en Terranova, donde se produjeron graves daños materiales y 28 víctimas mortales ... |
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