Extra-terrestrial $^{53}$Mn in Antarctic ice

• Published in: Earth and Planetary Science Letters
• Main Authors: Bibron, R., Chesselet, R., Crozaz, G., Leger, G., Mennessier, J.P., Picciotto, E.
• Other Authors: CEA- Saclay (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre des Faibles Radioactivités, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Fonds National de la Recherche Scientifique Bruxelles (FNRS), Université libre de Bruxelles (ULB)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1974
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarctic; Antarc*
• Online Access: https://hal.archives-ouvertes.fr/hal-03406787; https://doi.org/10.1016/0012-821X(74)90043-0

International audience The reasons why $^{53}$Mn (a cosmogenic radionuclide with a half-life of 3.7 × 10$^6$ y) appears as one of the best indicators of the presence of interplanetary dust are summarized. This paper reports the detection of $^{53}$Mn in pre-1952 snow samples collected on the Eastern Antarctic Plateau in the vicinity of Plateau Station. The measurements were carried out by neutron activation and X-ray spectrometry on three samples weighing a few hundred kg and covering each the time interval 1935–1950. The specific activity of $^{53}$Mn was found to be (0.82 ± 0.17) disint.min$^{−1}$/10$^3$ tons of snow, corresponding to a deposition rate at Plateau Station of (2.2 ± 0.5) × 10$^{−5}$ disint. min$^{-1}$ m$^{-2}$ y$^{-1}$. The mean global deposition rate would be three times higher if $^{53}$Mn were assumed to behave in the same way as stratospheric $^{90}$Sr. By comparing this figure with existing data on the meteorite flux reaching the earth and with the galactic and solar production rates of $^{53}$Mn, it is concluded that the bulk of the $^{53}$Mn found at Plateau Station is associated with interplanetary dust in which it had been produced by the action of solar protons on iron. The deposition rate of extra-terrestrial dust-borne iron must be between 1.3 × 10$^{-5}$ and 1.3 × 10$^{-4}$ g m$^{-3}$ y$^{-1}$ at Plateau Station. These results support jointly with other studies the concept of an interplanetary zodiacal cloud of dust with a chemical composition and density not essentially different from chondritic meteorites, with a relatively ‘flat’ grain size distribution and a mass influx to the earth of the order of 10$^5$ tons/y.