Grindlay, N. R., University of North Carolina W, Wilmington, USA, grindlayn@uncw.edu
Moore, W. S., University of South Carolina/Department of Geological Sciences, Columbia, USA, moore@geol.sc.edu
PE06-45 Shipboard Scientific Party, . ., , , ,

A DEEP-TOWED CAMERA INVESTIGATION OF DEEP FLUID FLOW SITES OFFSHORE NORTHERN PUERTO RICO

In 2005, a water sampling program to evaluate the contribution of submarine groundwater discharge to the coastal ocean offshore northern Puerto revealed strong signals of both long and short-lived radium isotopes at water depths of 2000-3100 m. We interpreted these findings as recent radium additions due to deep fluid flow. In September 2006, a five-day cruise that included the use of WHOI’s deep-towed camera system was conducted to visually document seep sites on the northern Puerto Rico margin. Targeted areas of TowCam deployments were chosen on the basis of excess radium activity identified in the 2005 cruise. The TowCam was equipped with a CTD and four 5-liter Niskin bottles. A total of seven camera tows and eight CTD/water sampling stations were completed. High-resolution digital photographs imaged white halos, presumably carbonate deposits associated with seeps, around a series of E-W trending fissures at the crown of the 55-km wide Arecibo amphitheater. The TowCam measured near-bottom turbidity and temperature anomalies associated with these fissures. As was the case in 2005, water samples showed clear elevated activity of all radium isotopes.

Poster presentation

Presentation is given by student: No
Session #:089
Date: 03-06-2008
Time: 17:30 - 19:30