262 PENG, T.-H., and BROECKER, W. S. 1984. "Ocean Life Cycles and the 

 Atmospheric CO, Content," Journal of Geophysical Research . Vol 89, No. C5 , 

 pp 8170-8180. 



The possibility that changes in the ocean's Redfield ratios, in the 

 ocean's plant productivity, or in the extent to which organic material is re- 

 cycled within the ocean have significantly altered the atmosphere's COj con- 

 tent over the past century is examined. Models show that the magnitudes of 

 the alteration in these processes necessary to produce significant COj changes 

 are unreasonably large. For those who do not wish to accept this theoretical 

 approach, we offer a means to directly monitor the impacts of life cycle 

 changes. It involves determining temporal trends in the dissolved Oj, NO3, 

 and PO4 contents of thermocline waters. While surveys carried out in 1972 

 (GEOSECS) and in 1981 (Transient Tracers in the Ocean) reveal no significant 

 trend for the thermocline of the North Atlantic over this 9-year period, a 

 longer period of observation will be necessary before firm limits can be 

 placed through this observational approach. (Authors) . 



263 PENLAND, S., RAMSEY, K. E., MOSLOW, T. F., and WESTPHAL, K. A. 1986 

 "Relative Sea-Level Rise and Subsidence in Louisiana and the Gulf of Mexico," 

 Louisiana Geological Survey, Coastal Geology Technical Report, Baton Rouge, 



LA. 



Two tide gage networks in Louisiana and the northern Gulf of Mexico were 

 analyzed to determine local and region trends in relative sea- level rise and 

 to determine subsidence using eustatic correction factors. Relative sea- level 

 rise rates in Louisiana range between 0.33 cm/year and 1.28 cm/year. Within 

 the Mississippi River delta plain, the Houma tide gage documented a maximum 

 relative sea- level rise rate of 1.24 cm/year for the entire record with rates 

 accelerating from 0.07 cm/year to 1.94 cm/year between 1946 and 1983. On the 

 coast, the Eugene Island tide gage documented a maximum relative sea- level 

 rise rate of 1.19 cm/year with rates accelerating from 0.95 cm/year to 

 2.17 cm/year between 1939 and 1979. A comparison of other tide gage stations 

 exceeding 30 years or more in record with the Houma tide gage station 

 indicates relative sea- level is rising faster in Terrebonne Parish than 

 anywhere else in Louisiana. Representative water level histories from the 

 Chenier Plain, Teche Basin, Terrebonne Delta Plain, Barataria Basin, 

 St. Bernard Delta Plain, and Ponchatrain Basin indicate the regional rates of 

 relative sea- level rise decrease east and west away from the Terrebonne Delta 

 plain. Rates of relative sea-level rise in the Teche Basin reach a maximum of 

 1.71 cm/year at Calumet, however these rates are affected by the Atchafalaya 

 River . 



In comparison with other National Ocean Survey tide stations throughout 

 the U.S. Gulf Coast, Terrebonne Parish is experiencing the highest relative 

 sea- level rise at 1.19 cm/year. In the surrounding coastal states, relative 

 sea-level rise rates decreases from 0.62 cm/year at Galveston, Texas to 

 0.15 cm/year in Biloxi, Mississippi. Mean relative sea-level rise in 

 Louisiana is more than 5 times the Gulf of Mexico relative sea- level rise rate 

 average. A comparison of the Eugene Island relative sea- level rise rate of 

 1.19 cm/year with the global relative sea- level rise rate of 0.12 cm/year 



119 



