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The geochemical and biological study of corals
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The shielding effect of coral reefs to create unusually low radiation environment on the surface of the earth
Monday 7th @ 1050-1110, Conference Room 4
Wuhui Lin* , Coral Reef Research Center of China, Guangxi University
Kefu Yu, Coral Reef Research Center of China, Guangxi University
Yinghui Wang, Coral Reef Research Center of China, Guangxi University
Tianlai Fan, Coral Reef Research Center of China, Guangxi University
Xueyong Huang, Coral Reef Research Center of China, Guangxi University
Presenter Email: linwuhui8@163.com |
| Variable intensity of ionizing radiation occurs from the surface environment to the interior of the Earth. High background radiation area (HBRA) had been widely investigated from the perspectives of uranium/thorium mineral resource searching and radiation dose-cancer effect interaction. In the present study, we exhibited unusually low radiation in the coral reef regions, the opposite endmember of HBRA, based on a three-dimensional viewpoint. From the horizontal perspective, extremely low radiation was observed in 12 locations of coral reefs in the South China Sea (SCS). From the vertical perspective, the natural gamma radiation derived from the field-based NaI gamma spectrometry and the natural radionuclides calculated from the laboratory-based HPGe gamma spectrometry also had extremely low values for a long coral core (928 m) located in the Xisha Island, SCS. It was noted that the mean radioactive level in the atoll reefs (3.97 Bq/kg) was less than 5% of that in global average soil (108.70 Bq/kg) and was <10% of that in HBRA (~104 Bq/kg). The reason for this low radioactivity is that coral skeletons and other biogenic carbonate skeletons (bivalve, Halimeda, coralline algae, foraminifera, etc.) have low radioactivity relative to high radioactivity of terrigenous minerals originating from Earth's interior followed by a series of geological processes. All in all, coral reefs with low radioactivity behave like a white cap to shield high radioactivity from the rock and mineral in Earth's crust. Coral reefs are probably the lowest radiation area on the surface of the Earth. The unique label of unusually low radioactivity in coral reefs was proposed and illustrated in addition to other traditional labels (good water quality, high biodiversity, high productivity, etc.). |
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