ABSTRACT

The concentrations of ⁸⁹Sr and ⁹⁰Sr in a total of 117 samples of individual rain and snow collected at Fayetteville (36°N, 94°W), Arkansas, were determined radiochemically during the period between September 1979 and August 1981. A spectacular increase in the concentration of ⁹⁰Sr in the atmospheric precipitation was observed during the month of March 1981, approximately 5 months after the 25th Chinese nuclear test of 16 Octuber 1980. A complicated pattern of variation of the ⁸⁹Sr/⁹⁰Sr ratio in rain observed after this nuclear explosion is interpreted in terms of the general theory of radioactive fallout based on the two-compartment model of the atmosphere, taking into consideration the fact that the nuclear debris released into the atmosphere at Lop Nor (40°N, 90°E), China, is known to travel eastward and circle the world more than once.