wae Evidences of Atmospheric Sterage in Fallout Data In Figure 13 are plotted the mean daily fallout, during the latter half of 1953, at 24 stations operated in various parts of the world. data ought to be found in Table 13. The individual The rate of failout in late Jun2 is largely from UPSHOT-KNOTHO The sharp rise in late August is vrobably due to foreign tests. It will be noted that the sharp decline wnich began in mid-September avcpears to be continujng in late October, ee Further studies will be required in order to satisfactorily identity the test series that contribute to this lw level depesition. As nofed earlier, the recent debris is considerably enriched in doth isotepes of s4rontium and the graduai accretion of these isotopes curing the coming mogtns is likely to be larger in amount taan the strontium that has been ddposited up to the present time, Estimate of AitureFallout, Based on Atmospheric Samples Based on the few data available, we would estimate the activity oF the atmo- sphere up to 100,000 feet to be of the order of .06 d/min/m3 (.00B d/min/ft3). Approximately 10% of this activity appears to be 3r79, If all of |thiz activity is to be deposited on the sarth’s surface in a time which isl]short in relation to the half life of Sr?%» the deposition would de of thelorder of 20 d/min/sq. ft. This is an amount whish is equavaiens to the sr 40 detosited by ali detonations up to the present in most of the United States, ney ~y Soo q a ek mee ee .