Measurement of fallout radionuclides, 239,240Pu and 137Cs, in soil and creek sediment: Sydney Basin, Australia

Contribution of close-in fallout from the French atmospheric tests in inventories of 137Cs, 241Am and plutonium (238, 239, 240) in Gambier Islands (French Polynesia) – Signatures of stratospheric fallout in the Southern Hemisphere

“…There is little comparative data in the Southern Hemisphere. Widely dispersed values, were measured in Australia on soils in the Sydney Basin (Smith et al, 2016). 137 Cs/ 239+240 Pu close to 7, similar to those of the Gambier, was observed in depth at Searchlight (150 km from the NTS).…”

“…The average ratios are 0.156 for sites in the east, not affected by local fallout. For 14 sites in the Sydney Basin, the values are more dispersed with an average of 0.146 0.013 (Smith et al, 2016). For sampling at Brisbane at the beginning of 1970, the measured value was 0.177 0.003 (Kelley et al, 1999), while that of the sampling of the years 2010 is 0.156 ± 0.010 ( Tims et al, 2013).…”

Global Peak in Atmospheric Radiocarbon Provides a Potential Definition for the Onset of the Anthropocene Epoch in 1965

“…The atmospheric maximum in radiocarbon in 1965 has been observed to fall on the steep rise in 14 C within marine sediments and carbonates 30 , providing a global marker across different environments. Furthermore, the association between 14 C and other radionuclides produced during nuclear bomb tests (e.g., 129 I and 239 Pu/ 240 Pu) preserved in marine and terrestrial records satisfies the requirement that a signal will be identified in sequences millions of years into the future, far beyond the dating limit of radiocarbon (albeit at lower resolution than the tree ring series reported here) 21 , 22 .…”

Plutonium Isotopes Research in the Marine Environment: A synthesis

“…The 240 Pu/ 239 Pu atom ratios in the sediments of the southeast coast of Australia showed lower values (0.11-0.16) caused by nuclear testing by the UK. 130 However, report on the 240 Pu/ 239 Pu atom ratios in the South Pacific are still lacking. Though a number of studies have reported the long-range transport of Pu in the Western Pacific and its marginal seas, their conclusions were only indirect speculation based on the 240 Pu/ 239 Pu atom ratios.…”

“…Sellafield derived Pu was transported northward along the west coast of Northern Europe via the North Atlantic Warm Current and the Norwegian Warm Current. This Atlantic derived Pu could enter the Arctic Ocean and affect the The synthesis of 240 Pu/ 239 Pu atom ratios in the areas surrounding the Pacific: Soil (black color),32,139,140,[142][143][144][145] sediment (red color),18,22,[83][84][85][86][87][88][89][90]130,140,[146][147][148] seawater (blue color)[149][150][151][152][153][154][155][156][157] and a coral (yellow color) 23,117,129. NEC: North Equatorial Current; SEC: South Equatorial Current;…”