A decadal record of underflows from a coastal river into the deep sea

• Published in: Geology (Boulder) 2001-11, Vol.29 (11), p.1019-1022
• Main Authors: Johnson, Kenneth S, Paull, Charles K, Barry, James P, Chavez, Francisco P
• Format: Article
• Language: English
• Subjects: bedload; California; coastal sedimentation; continental margin sedimentation; currents; decadal variations; East Pacific; Geology; Hydrogeology; hydrology; hyperpycnal flow; marine environment; marine sediments; Monterey Bay; Monterey Canyon; Monterey County California; North Pacific; Northeast Pacific; observations; ocean floors; Oceanography; Pacific Ocean; provenance; Rivers; rivers and streams; Salinas River; sediment transport; sedimentation; Sediments; streamflow; submarine canyons; submarine environment; suspended materials; turbidity currents; United States
• ISSN: 0091-7613; 1943-2682
• DOI: 10.1130/0091-7613(2001)029<1019:ADROUF>2.0.CO;2

Four periods of extreme turbidity were measured in Monterey Submarine Canyon over the past 12 yrs. These turbid events occurred simultaneously with the four largest flood events of the nearby Salinas River. They filled the canyon with fresher, warmer, and, apparently, buoyant water that extended to depths below 1 km. The low-salinity signature must reflect underflow of the Salinas River plume that was driven to depth by negative buoyancy contributed from the suspended sediment. A flux estimate for the 1995 event suggests that one-half, or more, of the river's suspended sediment load was carried down the canyon in the underflow. Underflows may contribute significantly to the carbon budget of the continental slope.