دورية أكاديمية
Polonium-210 dynamics in the northern Gulf of Mexico
| العنوان: | Polonium-210 dynamics in the northern Gulf of Mexico |
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| المؤلفون: | Jones, Patrick Robert |
| المصدر: | LSU Master's Theses |
| بيانات النشر: | LSU Digital Commons |
| سنة النشر: | 2014 |
| المجموعة: | LSU Digital Commons (Louisiana State University) |
| مصطلحات موضوعية: | Hypoxia, Bioaccumulation, Remobilization, Alpha Particle, Oceanography and Atmospheric Sciences and Meteorology |
| الوصف: | Polonium-210 (t1/2=138 d) is the most common among the 33 known radioisotopes of Polonium found in the natural environment. It is produced by the radioactive decay of its long-lived grandparent Lead-210(t1/2=22.3 d) via Bismuth-210 (t1/2=5.012 d) and forms as part of the natural Uranium-238 decay series. The primary hazard associated with Polonium-210 is its radioactivity, as an alpha particle emitter. Marine organisms receive their maximum radioactive dose in the natural environment from Polonium-210. Polonium has been known to bioaccumulate in the marine food web and can be potentially harmful to humans via the intake of certain marine organisms. Thus it is important to understand the source and sink of Polonium-210 in the marine environment. A number of studies in the past have observed Polonium-210 remobilization from sediments in anoxic lake environments but the release mechanism has never been studied in low oxygen marine systems. On the other hand, the biological affinity of Polonium-210 allows it to be used as an effective tracer of POC export from the upper ocean, although no such study using Polonium-210 as a tracer of POC flux has been carried out in the northern Gulf of Mexico. The present work is aimed at understanding both remobilization of Polonium-210 from sediments in the hypoxia zone of the northern Gulf of Mexico and utilizing Polonium-210 as a tracer of POC export in the northern Gulf of Mexico. Results from our study indicate Polonium-210 was enriched in bottom waters by as much as 50% compared to surface waters from sample stations in the hypoxia zone in 2011 and 2012. No strong correlation between oxygen concentration and unsupported Polonium-210 activity was apparent. However, there was a good correlation between Polonium-210 enrichment and the release of redox sensitive trace metals like Fe and Mn. Due to the affinity of Polonium-210 to Fe and Mn, the cycling of redox sensitive elements such as Fe and Mn and the degradation of organic matter in the water column are likely the driving ... |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | unknown |
| العلاقة: | https://digitalcommons.lsu.edu/gradschool_theses/2699Test; https://digitalcommons.lsu.edu/context/gradschool_theses/article/3698/viewcontent/uc.pdfTest |
| DOI: | 10.31390/gradschool_theses.2699 |
| الإتاحة: | https://doi.org/10.31390/gradschool_theses.2699Test https://digitalcommons.lsu.edu/gradschool_theses/2699Test https://digitalcommons.lsu.edu/context/gradschool_theses/article/3698/viewcontent/uc.pdfTest |
| رقم الانضمام: | edsbas.9511CB1B |
| قاعدة البيانات: | BASE |
| DOI: | 10.31390/gradschool_theses.2699 |
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