TY - JOUR
T1 - Potential Role of Event-Driven Sediment Transport on Sediment Accumulation in the Cariaco Basin, Venezuela
AU - Lorenzoni, Laura
AU - Benitez-Nelson, C. R
AU - Thunell, R. C
AU - Hollander, D.
AU - Varela, R.
AU - Astor, Y.
AU - Audemard, F. A
AU - Muller-Karger, Frank E
PY - 2012/1/1
Y1 - 2012/1/1
N2 - A sediment density flow was observed in the eastern Cariaco Basin during September 2008. Evidence suggests that this flow was likely triggered by a magnitude 5.2 earthquake that occurred on August 11, 2008, with an epicenter located at 10.51°N, 64.17°W (off the city of Cumaná, Venezuela). Elevated suspended sediments near the bottom were observed at the mouth of the Manzanares Canyon (>90gm -2, over a depth of 165m) and decreased to ~11gm -2 (over a depth of 40m) 42km away from the canyon's mouth at the CARIACO Ocean Time-Series site. The sediment flux associated with this single event was ~10% of the total annual sediment flux that typically reaches the Cariaco Basin deep seafloor. Carbon to nitrogen ratios and isotope composition confirm that most of the organic matter transferred by the sediment flow was of continental origin (C/N ratios of ~17.67, δ 13C of -27.04‰, and δ 15N of 6.83‰). Our observations contribute to the growing body of evidence that suggests that submarine canyons are rapid, efficient sediment conduits of particles from shallow to deep waters, and that they should be included in efforts to constrain estimates of sediment and terrestrially derived carbon transport from the continental shelves to the deep ocean.
AB - A sediment density flow was observed in the eastern Cariaco Basin during September 2008. Evidence suggests that this flow was likely triggered by a magnitude 5.2 earthquake that occurred on August 11, 2008, with an epicenter located at 10.51°N, 64.17°W (off the city of Cumaná, Venezuela). Elevated suspended sediments near the bottom were observed at the mouth of the Manzanares Canyon (>90gm -2, over a depth of 165m) and decreased to ~11gm -2 (over a depth of 40m) 42km away from the canyon's mouth at the CARIACO Ocean Time-Series site. The sediment flux associated with this single event was ~10% of the total annual sediment flux that typically reaches the Cariaco Basin deep seafloor. Carbon to nitrogen ratios and isotope composition confirm that most of the organic matter transferred by the sediment flow was of continental origin (C/N ratios of ~17.67, δ 13C of -27.04‰, and δ 15N of 6.83‰). Our observations contribute to the growing body of evidence that suggests that submarine canyons are rapid, efficient sediment conduits of particles from shallow to deep waters, and that they should be included in efforts to constrain estimates of sediment and terrestrially derived carbon transport from the continental shelves to the deep ocean.
KW - Cariaco Basin
KW - Continental organic carbon
KW - Episodic event
KW - Manzanares Submarine Canyon
KW - Sediment density flow
KW - Sediment transport
UR - https://digitalcommons.usf.edu/msc_facpub/1072
UR - http://10.1016/j.margeo.2011.12.009
U2 - 10.1016/j.margeo.2011.12.009
DO - 10.1016/j.margeo.2011.12.009
M3 - Article
VL - 307-310
JO - Marine Geology
JF - Marine Geology
ER -