Continuous transport of Pacific-derived anthropogenic radionuclides towards the Indian Ocean
نویسندگان
چکیده
Unusually high concentrations of americium and plutonium have been observed in a sediment core collected from the eastern Lombok Basin between Sumba and Sumbawa Islands in the Indonesian Archipelago. Gamma spectrometry and accelerator mass spectrometry data together with radiometric dating of the core provide a high-resolution record of ongoing deposition of anthropogenic radionuclides. A plutonium signature characteristic of the Pacific Proving Grounds (PPG) dominates in the first two decades after the start of the high yield atmospheric tests in 1950's. Approximately 40-70% of plutonium at this site in the post 1970 period originates from the PPG. This sediment record of transuranic isotopes deposition over the last 55 years provides evidence for the continuous long-distance transport of particle-reactive radionuclides from the Pacific Ocean towards the Indian Ocean.
منابع مشابه
Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California.
The Fukushima Dai-ichi release of radionuclides into ocean waters caused significant local and global concern regarding the spread of radioactive material. We report unequivocal evidence that Pacific bluefin tuna, Thunnus orientalis, transported Fukushima-derived radionuclides across the entire North Pacific Ocean. We measured γ-emitting radionuclides in California-caught tunas and found (134)C...
متن کاملFukushima radionuclides in the NW Pacific, and assessment of doses for Japanese and world population from ingestion of seafood
Variations of Fukushima-derived radionuclides ((90)Sr, (134)Cs and (137)Cs) in seawater and biota offshore Fukushima and in the NW Pacific Ocean were investigated and radiation doses to the Japanese and world population from ingestion of seafood contaminated by Fukushima radionuclides were estimated and compared with those from other sources of anthropogenic and natural radionuclides. The total...
متن کاملIncrease of total alkalinity due to shoaling of aragonite saturation horizon in the Pacific and Indian Oceans: Influence of anthropogenic carbon inputs
[1] Aragonite saturation horizon (ASH) shallowed significantly by 25 to 155 m and 16 to 124 m in the Pacific and Indian Ocean respectively in two decades. Apparent oxygen utilization (AOU) increased by 3 to 34 and 0.5 to 31.5 mmol kg 1 in the Pacific and Indian Ocean respectively at the depth of ASH during this period. DIC increased by 12.5 to 36.8 and 5.5 to 32 mmol kg 1 in the vicinity of ASH...
متن کاملDistribution Modeling of Bigeye Tuna (Thunnus obesus Lowe, 1839), Using Satellite Derived Environmental Variables in Indian Ocean
Understanding effects of environment on the distribution of economic fish is a fundamental step in the ecosystem-based management and ultimately a standard approach in management policies. Bigeye tuna (Thunnus obesus) is one of the most important aquatic species harvested in the Indian Ocean. The present study investigated the association of different variables effecting the rate of catch and d...
متن کاملThe heat transport of the Indonesian Throughflow and implications for the Indian Ocean heat budget
The Indonesian Throughflow (ITF) is considered central to the heat budgets of the Pacific and Indian Oceans. Temperature and ocean current time series obtained within the Makassar Strait from December 1996 to early July 1998 are used to calculate heat transport of the ITF and assess its influence on Indian Ocean heat divergence. Velocity and temperature values for the surface layer that were no...
متن کامل