In contrast to the subaquatic sulphide and carbonate chimneys, which are known from Mid Ocean Ridges and abyssal submarine volcanoes, chimneys built of salts have not been described yet. Here we present such halite chimneys as a new form of cold-water smokers in hypersaline environments. The here described structures rise up from the bottom of the Dead Sea and result from the submarine discharge of saturated halite-dissolution brines into the salt lake, which is at halite saturation and holds remarkable chloride excess.
View Article and Find Full Text PDFThe opportunity to measure the concentrations of H and Cl released by the Fukushima nuclear accident in 2011 directly in rain was lost in the early stage of the accident. We have, however, been able to reconstruct the deposition record of atmospheric H and Cl following the accident using a bore hole that was drilled in 2014 at Koriyama at a distance of 60 km from the accident. The contributions of H and Cl from the accident are 1.
View Article and Find Full Text PDFPlutonium (Pu) has been used as a mid-twentieth century time-marker in various geological archives as a result of atmospheric nuclear tests mainly conducted in 1950s. Advancement of analytical techniques allows us to measure Pu and Pu more accurately and can thereby reconstruct the Pacific Pu signal that originated from the former Pacific Proving Grounds (PPG) in the Marshall Islands. Here, we propose a novel method that couples annual banded reef building corals and nearshore anoxic marine sediments to provide a marker to precisely determine the start of the nuclear era which is known as a part of the Anthropocene.
View Article and Find Full Text PDFJ Environ Radioact
July 2022
Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust-iron-60 (Fe) (half-life, 2.
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