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Earthquakes drive large-scale submarine canyon development and sediment supply to deep-ocean basins

Although the global flux of sediment and carbon from land to the coastal ocean is well known, the volume of material that reaches the deep ocean—the ultimate sink—and the mechanisms by which it is transferred are poorly documented. Using a globally unique data set of repeat seafloor measurements and...

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Detalles Bibliográficos
Autores principales: Mountjoy, Joshu J., Howarth, Jamie D., Orpin, Alan R., Barnes, Philip M., Bowden, David A., Rowden, Ashley A., Schimel, Alexandre C. G., Holden, Caroline, Horgan, Huw J., Nodder, Scott D., Patton, Jason R., Lamarche, Geoffroy, Gerstenberger, Matthew, Micallef, Aaron, Pallentin, Arne, Kane, Tim
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5851666/
https://www.ncbi.nlm.nih.gov/pubmed/29546245
http://dx.doi.org/10.1126/sciadv.aar3748
Descripción
Sumario:Although the global flux of sediment and carbon from land to the coastal ocean is well known, the volume of material that reaches the deep ocean—the ultimate sink—and the mechanisms by which it is transferred are poorly documented. Using a globally unique data set of repeat seafloor measurements and samples, we show that the moment magnitude (M(w)) 7.8 November 2016 Kaikōura earthquake (New Zealand) triggered widespread landslides in a submarine canyon, causing a powerful “canyon flushing” event and turbidity current that traveled >680 km along one of the world’s longest deep-sea channels. These observations provide the first quantification of seafloor landscape change and large-scale sediment transport associated with an earthquake-triggered full canyon flushing event. The calculated interevent time of ~140 years indicates a canyon incision rate of 40 mm year(−1), substantially higher than that of most terrestrial rivers, while synchronously transferring large volumes of sediment [850 metric megatons (Mt)] and organic carbon (7 Mt) to the deep ocean. These observations demonstrate that earthquake-triggered canyon flushing is a primary driver of submarine canyon development and material transfer from active continental margins to the deep ocean.