Increased Marine Sediment Suspension and Fluxes Following an Earthquake

• Published in: Nature
• Main Authors: Thunell, R., Tappa, E., Varala, R., Llano, M., Astor, Y., Muller-Karger, Frank E, Bohrer, R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Digital Commons @ University of South Florida 1999
• Subjects: Ewing; North Atlantic
• Online Access: https://digitalcommons.usf.edu/msc_facpub/1180; https://doi.org/10.1038/18430

Earthquakes are commonly cited as one possible triggering mechanism for turbidity flows - dense sediment-water plumes that can transport large volumes of sediment great distances clown slope - in both marine and lacustrine settings. Heezen and Ewing were the first to make such a suggestion, attributing breaks in a sea-floor telephone cable in the North Atlantic Ocean to turbidity flows generated by the 1929 Grand Banks earthquake. A number of workers have consequently used sedimentary turbidite records to reconstruct the earthquake histories of various regions. Here we present direct observations of a seismically induced turbidity flow. Measurements of light scattering and sediment fluxes in the Cariaco basin indicate that the earthquake that occurred along the coast of northern Venezuela on 9 July 1997 resulted in considerable downslope displacement of sediments - probably > 105 tonnes into the deep part of the basin. In such a seismically active region, this mechanism of sediment transport may be responsible for a significant component of the long-term sediment accumulation in the basin. Furthermore, this process may result in the sequestration in deep sea sediments of large amounts of carbon initially deposited at shallow depths.