C" and H^ Shoreside Measurements 



The GEOSECS project will generate about 1,200 C^* samples and 

 about 2,500 H^ samples. Of the C* samples, about 900 will most likely 

 be collected below 200 meters; for these, the greatest possible precision 

 and accuracy is desired. In the C^* scale a precision of better than four 

 parts per mille and an accuracy of better than five parts per mille, all 

 experimental errors included, have been stipulated by the GEOSECS 

 Advisory Committee. No existing radiocarbon laboratory can presently 

 process a significant number of samples meeting these criteria. 



Analytical facilities capable of such accuracy have been constructed 

 at the University of Miami and at the University of Washington. It is 

 expected that these facilities will be functional before the start of the 

 major cruise in July 1972. 



Preparatory Cruises 



Until the present time there have been three intercalibration cruises, 

 designed to allow the various investigators to intercalibrate their methods 

 and to obtain detailed vertical profiles in the areas where the main cruise 

 tracks will run. 



During the period September 23-30, 1969, a test station was estab- 

 lished in the Pacific Ocean at 28°29' N., 121°38' W. The results of inter- 

 calibrations from this cruise have been reported in the Journal of Geo- 

 phrjsical Research, 75: 7639-7696 (1970). A second cruise aboard 

 RV Knorr from August 24 to September 2, 1970, established a test station 

 22 at 35°46' N., 67°59' W. Results from this cruise will be published late 



in 1971. 



A third intercalibration and test cruise was completed in August 

 1971 as part of the Scripps Institution of Oceanography Antipode Ex- 

 pedition to the South Pacific aboard RV Melville. For November 1971 

 and January 1972, short cruises are planned for the testing of the com- 

 plete shipboard analytical systems. 



HISTORICAL BENCHMARK DATA FROM 

 MUSEUM COLLECTIONS 



In natural history museums throughout the world there are large 

 collections of biological specimens of diiferent types, both terrestrial and 

 marine. There are 53 million specimens in the U.S. National Museum 

 alone. Many of the specimens were collected during the last 200 years, 

 before levels of industrial pollutants in lakes, rivers, and oceans had 

 reached their present values. It seems possible that chemical analysis of 

 some of the specimens in the older collections, depending on the way in 

 which the specimens were preserved, might permit extension of pollutant 

 baseline data backward in time. The statistical value of this possibility 

 alone justifies the attempt. 



A task force of ten scientists of the Smithsonian Institution's Na- 

 tional Museum of Natural History has organized to examine for the U.S. 

 IDOE program in Environmental Quality the feasibility of studying 

 museum materials for pollutants. They are presently studying the vari- 



