抄録
The amount of excess 210Po activity injected into the atmosphere by the 18 May 1980 eruption of Mount St. Helens was greater than that of 90Sr released by the 16 October 1980 Chinese test explosion of a 0.2 to 1 megaton nuclear device. The occurrence of a ‘mystery’ cloud prior to the 28 March 1982 eruption of El Chichón volcano was accompanied by an increase in the 210Po/210Pb ratio in rain samples collected at Fayetteville, Arkansas, during the months of January and February, 1982.
