Area of Operations: Blake Plateau, United States, North America, North Atlantic
Dates: October 05, 1989 to October 15, 1989
Chief scientist: Frank Manheim
Pete Popenoe
Objectives: To study the deep scour pits on the northern Blake Plateau to determine the nature of erosion or solution, the age and nature of the outcropping rocks, the nature of the biomass supporting large fish concentrations reported in this area, the thickness of the phosphorite-manganese pavements over the Blake Plateau, and the fracture patterns and their orientation; to visit the "Aluminaut Hole" and measure the water salinity within erosional pits to determine possible presence of fresh water nodules and their occurence; to determine if pavement is discontinuous; to examine and groundcheck features seen on GLORIA long-range sidescan sonar mosaic; to measure current velocity, temperature and direction throughout the area to determine the extent south-flowing undercurrents have contributed to scour topography; and to study the deepwater ahermatypic reef mounds.
Type of Activity:
Information to be derived:
Summary: Sediment samplers were not placed into operating position due to heavy seas (must be emplaced by divers). Approximately 70 nautical miles (140 km) were traversed in view of the bottom. Approximately 35 nm of the bottom were recorded on video tape. Approximately 50 nm were recorded with sidescan sonar. Approximately 360 photographs of the bottom were made with hand-held cameras; 633 photos were taken with the external Benthos camera system.
Contact: Frank Manheim (fmanheim@usgs.gov)
Pete Popenoe (ppopenoe@usgs.gov)
InfoBank: uses the identifier N-1-89-EC. Visit this site for more information.
Related Links:
| 
U.S. Department of the Interior |
U.S. Geological Survey
