M ovement of Water Masses in Galveston Harbor 

 Cornelius R. Mock 



Todd Shipyard located on Pelican Island in the port of Galveston 

 has been chosen as a docking and servicing facility for the nuclear po^vered 

 ship SAVANNAH. 



Although refueling of the vessel is a relatively safe process, it 

 is likely that if an accident should occur during the handling, the general 

 area would become contaminated. With this in mind, the Navy Hydrographic 

 Office in Washington, D. C. , the U. S. Army Corps of Engineers (Galveston 

 District), and the Bureau of Commercial Fisheries Biological Laboratory 

 cooperated in an investigation of the movement of water masses through the 

 Galveston Harbor area. 



The investigation was begun on May 4, 1962, with the first few 

 days being spent surveying the area and adapting equipnnent and methods for 

 the study. Background fluorescence was monitored with a fluorometer. This 

 instrument was adapted for operation while underway by securing a hollow 

 tube to the side of the boat. A sample of water from a constant depth of 6 

 feet was drawn directly, by way of the tube, to a receiving tank aboard the 

 vessel. A bypass was installed to monitor a con stant^ volume of the water. 

 An induction conductivity salinometer was used to obtain depth profiles of 

 salinity and temperature. 



Rhodamine B, a red fluorescent dye in a liquid form, was used to 

 trace the flow pattern from the vicinity of Todd Shipyard. Fifty gallons of 

 this dye were introduced into the water May 7, 1962, at 0530 hours, which 

 marked the beginning of a strong flooding diurnal tide. The patch of stained 

 water began to drift westward along the Galveston Channel. Upon reaching 

 the area west of Pelican Island Bridge, the patch immediately took on a 

 northwesterly to northerly route. The dye then began to spread out in the 

 pocket between the Texas City Dike, Galveston Intracoastal Waterway, and 

 the naainland. After the dye became too diluted for visual recognition, the 

 fluorometer continued to make contact at the northern tip of Pelican Island 

 and southwest of the Texas City Dike. 



In a second test initiated on May 15 at 0530 hours, dye was re- 

 leased at the beginning of a weak, ebbing, semidiurnal tide. It moved very 

 slowly for about a mile in an eastwardly direction. With the combination of 

 a 15- to 20 -mile southwesterly wind and the onset of the flooding tide, the 

 movement of the dye patch reversed toward Todd Shipyard and along the 



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