600 ee 1 709 T T r ] T T ! l T STRONTIUM- 90 CONCENTRATIONS 65,000 Ft. 60,000 Ft. O ° 400r- e gr°° (dpm 1000 SCF) e Oo e 300F- O a A a A 100k 4 A a e ; °° 4 e 0 200+ © e Ls A e e . @ e 4 A e ° oO O O Oo 0 O Oo Oo O S 0 oO ORF | ] L N-0 | JF M-A M-v 1957 LL. 4 4 I L L J-A S-O N-D]uU-F M-A M-JU 1958 ij J-A 1959 \ S-0 L | } Fig. 5 -- Strontium-90 concentrations (in dpm/1000 scf) at 60, 000, 65,000, and 70, 000 feet versus time for latitude band t9 30°N~-30°S | NO | oF M-A M-d 1960