Espectrometria de raios gama e emissão de radônio em solos da região do Maciço Sienítico Piquiri (Cachoeira do Sul e Encruzilhada do Sul, RS)

This study was focused in performing a gamma radiation survey and measurements of radon concentration in soils from the Piquiri Syenite Massif, an intrusion located at central area of the Rio Grande do Sul State. This intrusion has alkaline affiliation with high concentrations of uranium in accessory minerals as zircon, sphene, apatite, and others. The gamma radiation measurements were made considering a grid with squares about 2 km side each, using the gamma spectrometer RS-125, obtaining counts per second (cps), dose rate (DR) and concentrations of K, eU and eTh. Moreover, measurements of 220Rn and 222Rn in soil were made using the AlphaGUARD equipment. The counts per second values obtained in this study range from 130 to 1045, the dose rate from 28.9 nSv/h to 424.6 nSv/h, the K concentration from 0.5 % to 8.3 %, the eU concentration from 0.8 ppm to 25.8 ppm, and the eTh concentration from 3.0 ppm to 99.2 ppm. The distribution of K defines with relatively precision the lithological contacts of the Piquiri Syenite Massif and between the two main facies of the intrusion (Main and Marginal Facies). The Main Facies of the syenite contains the highest concentrations of eTh, while the highest concentrations of eU were measured in the north area of this facies. The 220Rn and 222Rn concentrations range from 10 kBq/m3 to 550 kBq/m3 and from 5 kBq/m3 to 400 kBq/m3 , respectively, in the Main and Marginal Facies. The high values of radon measured in Main Facies of the Piquiri Syenite Intrusion may indicate high potential risk to the health of inhabitants in the area.Foram realizadas medidas de radiação gama e de concentração de radônio em solos da região do Maciço Sienítico Piquiri, região central do Estado do Rio Grande do Sul. Esta intrusão apresenta afinidade alcalina na qual a mineralogia acessória compreende presença relativamente abundante de titanita, apatita e zircão, entre outros minerais que podem conter elevadas concentrações de urânio. As medições de radiação gama foram feitas a partir de uma malha com quadrículas de 2 km de lado, utilizando o Espectrômetro de Radiação Gama RS-125, obtendo-se resultados em contagem por segundo (cps), taxa de dose (Dr) e concentrações de K, eU e eTh. As medidas de 220Rn e 222Rn no ar dos solos foram feitas com uso do equipamento AlphaGUARD. Os valores de cps obtidos neste estudo variam entre 130 e 1045, os de taxa de dose, entre 28,9 nSv/h e 424,6 nSv/h e as concentrações de K, entre 0,5 % e 8,3 %. As concentrações de eU se situam entre 0,8 ppm e 25,8 ppm, e as concentrações de eTh entre 3,0 ppm e 99,2 ppm. A distribuição de K permite definir com relativa precisão os contatos litológicos do Maciço sienítico Piquiri com as rochas adjacentes e entre as duas fácies (Fácies de Borda e Fácies Principal). As maiores concentrações de eTh estão na Fácies Principal do sienito, e as maiores concentrações de eU foram medidas na zona norte desta fácies. Os resultados de 220Rn e 222Rn para o ar contido no solo variam entre 10 kBq/m3 e 550 kBq/ m3 e entre 5 kBq/m3 e 400 kBq/m3 , respectivamente, para a Fácies Principal e de Borda. As elevadas concentrações de Rn na Fácies Principal podem indicar potencial risco à saúde dos habitantes da área

Chemical Weathering of Loess and Its Contribution to Global Alkalinity Fluxes to the Coastal Zone During the Last Glacial Maximum, Mid‐Holocene, and Present

Loess sediments are windblown silt deposits with, in general, a carbonate grain content of up to 30%. While regionally, loess was reported to increase weathering fluxes substantially, the influence on global weathering fluxes remains unknown. Especially on glacial‐interglacial time scales, loess weathering fluxes might have contributed to land‐ocean alkalinity flux variability since the loess areal extent during glacial epochs was larger. To quantify loess weathering fluxes, global maps representing the loess distribution were compiled. Water chemistry of rivers draining recent loess deposits suggests that loess contributes over‐proportionally to alkalinity concentrations if compared to the mean of alkalinity concentrations of global rivers (~4,110 µeq L−1 for rivers draining loess deposits and ~1,850 µeq L−1 for the total of global rivers), showing comparable alkalinity concentration patterns in rivers as found for carbonate sedimentary rocks. Loess deposits, covering ~4% of the ice‐ and water‐free land area, increase calculated global alkalinity fluxes to the coastal zone by 16%. The new calculations lead to estimating a 4% higher global alkalinity flux during the Last Glacial Maximum (LGM) compared to present fluxes. The effect of loess on that comparison is high. Alkalinity fluxes from silicate‐dominated lithological classes were ~28% and ~30% lower during the LGM than recent (with loess and without loess, respectively), and elevated alkalinity fluxes from loess deposits compensated for this. Enhanced loess weathering dampens due to a legacy effect changes in silicate‐dominated lithologies over the glacial‐interglacial time scale

Short Communication: Aging of basalt volcanic systems and decreasing CO<sub>2</sub> consumption by weathering

Basalt weathering is one of many relevant processes balancing the global carbon cycle via land-ocean alkalinity fluxes. The CO2 consumption by weathering can be calculated using alkalinity and is often scaled with runoff and/or temperature. Here it is tested if information on the surface age distribution of a volcanic system is a useful proxy for changes in alkalinity production with time. A linear relationship between temperature normalized alkalinity fluxes and the Holocene area fraction of a volcanic field was identified, using information from 33 basalt volcanic fields, with an r2=0.91. This relationship is interpreted as an aging function and suggests that fluxes from Holocene areas are ~10 times higher than those from old inactive volcanic fields. However, the cause for the decrease with time is probably a combination of effects, including a decrease in alkalinity production from surface near material in the critical zone as well as a decline in hydrothermal activity and magmatic CO2 contribution. A comparison with global models suggests, that global alkalinity fluxes considering Holocene active basalt areas are ~70% higher than the average from these models imply. The contribution of Holocene areas to the global basalt alkalinity fluxes is however only ~6%, because identified, mapped Holocene basalt areas cover only ~1% of the existing basalt areas. The large trap basalt proportion on the global basalt areas today reduces the relevance of the aging effect. However, the aging effect might be a relevant process during periods of globally, intensive volcanic activity, which remains to be tested

Ecosystem controlled soil-rock p CO 2 and carbonate weathering – Constraints by temperature and soil water content

Carbonate dissolution in soil-groundwater systems depends dominantly on pH, temperature and the saturation state of the solution with respect to abundant minerals. The pH of the solution is, in general, controlled by partial pressure of CO2 (pCO2) produced by ecosystem respiration, which is controlled by temperature and water availability. In order to better understand the control of land temperature on carbonate weathering, a database of published spring water hydrogeochemistry was built and analysed. Assuming that spring water is in equilibrium with the soil-water-rock-atmosphere, the soil pCO2 can be back-calculated. Based on a database of spring water chemistry, the average soil-rock CO2 was calculated by an inverse model framework and a strong relationship with temperature was observed. The identified relationship suggests a temperature control on carbonate weathering as a result of variations in soil-rock pCO2, which is itself controlled by ecosystem respiration processes. The findings are relevant for global scale analysis of carbonate weathering and carbon fluxes to the ocean, because concentration of weathering products from the soil-rock-system into the river system in humid, high temperature regions, are suggested to be larger than in low temperature regions. Furthermore, results suggest that, in specific spring samples, the hydrochemical evolution of rain water percolating through the soil-rock complex can best be described by an open system with pCO2 controlled by the ecosystem. Abundance of evaporites and pyrite sources influence significantly the chemistry of spring water and corrections must be taken into account in order to implement the inverse model framework presented in this study. Annual surface temperature and soil water content were identified as suitable variables to develop the parameterization of soil-rock pCO2, mechanistically consistent with soil respiration rate findings

Increasing Senior Enrollment in 3SquaresVT

Background: Hunger Free Vermont’s mission is to feed more Vermonters, teach the community about healthy food and nutrition and lead advocacy and education efforts to end hunger in Vermont. In Vermont 11.4% of all seniors are considered food insecure. To address this issue, Hunger Free Vermont has taken on the task of increasing enrollment in 3Squares Vermont, the state food stamps program. 68% of people in VT who are eligible for 3SqVT are enrolled. Surprisingly, only 29.2% of eligible seniors are enrolled. Our study focuses on the leaders of community organizations who impact seniors. Through focus groups we assessed their: - Knowledge of the 3SqV program - Knowledge of senior enrollment and food insecurity - Ideas about the barriers leading to low enrollment - Solutionshttps://scholarworks.uvm.edu/comphp_gallery/1056/thumbnail.jp

The Earth system model CLIMBER-X v1.0 – Part 2: The global carbon cycle

The carbon cycle component of the newly developed Earth system model of intermediate complexity CLIMBER-X is presented. The model represents the cycling of carbon through the atmosphere, vegetation, soils, seawater and marine sediments. Exchanges of carbon with geological reservoirs occur through sediment burial, rock weathering and volcanic degassing. The state-of-the-art HAMOCC6 model is employed to simulate ocean biogeochemistry and marine sediment processes. The land model PALADYN simulates the processes related to vegetation and soil carbon dynamics, including permafrost and peatlands. The dust cycle in the model allows for an interactive determination of the input of the micro-nutrient iron into the ocean. A rock weathering scheme is implemented in the model, with the weathering rate depending on lithology, runoff and soil temperature. CLIMBER-X includes a simple representation of the methane cycle, with explicitly modelled natural emissions from land and the assumption of a constant residence time of CH4 in the atmosphere. Carbon isotopes 13C and 14C are tracked through all model compartments and provide a useful diagnostic for model–data comparison. A comprehensive evaluation of the model performance for the present day and the historical period shows that CLIMBER-X is capable of realistically reproducing the historical evolution of atmospheric CO2 and CH4 but also the spatial distribution of carbon on land and the 3D structure of biogeochemical ocean tracers. The analysis of model performance is complemented by an assessment of carbon cycle feedbacks and model sensitivities compared to state-of-the-art Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Enabling an interactive carbon cycle in CLIMBER-X results in a relatively minor slow-down of model computational performance by ∼ 20 % compared to a throughput of ∼ 10 000 simulation years per day on a single node with 16 CPUs on a high-performance computer in a climate-only model set-up. CLIMBER-X is therefore well suited to investigating the feedbacks between climate and the carbon cycle on temporal scales ranging from decades to &gt;100 000 years.</p

Espectrometria de raios gama e concentrações de radônio em solos da Região do Maciço Sienítico Piquiri, municípios de Cachoeira do Sul/Encruzilhada do Sul, RS

A concentração de radônio no interior das construções está fortemente relacionada com a concentração de urânio das rochas. O Maciço Sienítico Piquiri representa um complexo de intrusão de rochas sieníticas que apresentam altas concentrações de urânio devido a minerais acessórios como zircão, titanita, apatita e outros. O objetivo do presente estudo foi realizar medidas radiométricas e de concentração de Rn nos solos da região do Maciço Sienítico Piquiri, para entender a potencialidade de risco para a saúde das pessoas que vivem nesta região. Para realizar as medidas radiométricas foi feita uma grade de quadrículas de 4 Km2 de área, usando o equipamento RS-125 para medir in situ e obter resultados de contagem por segundo, taxa de dose, concentração de potássio, concentração de equivalente-urânio e concentração de equivalente-tório. Por outro lado, foi utilizado o equipamento AlphaGUARD para fazer medições in situ de concentração de Rn no ar dos solos da região, concentrando os pontos de amostragem nas áreas de maiores valores de medidas radiométricas. Os valores de cps obtidos neste estudo variam entre 130 e 1045, os de taxa de dose, entre 28,9 nSv/h e 424,6 nSv/h, as concentrações de K, entre 0,5 % e 8,3 %, as concentrações de eU, entre 0,8 ppm e 25,8 ppm, e as concentrações de eTh, entre 3,0 ppm e 99,2 ppm. A distribuição de K delimita os contatos litológicos do Maciço sienítico Piquiri, enquanto as maiores concentrações de eTh estão na Fácies Principal do sienito, e as maiores concentrações de eU foram medidas na zona norte da Fácies Principal da intrusão. Os resultados de 220Rn e 222Rn variam entre 10 KBq/m3 e 550 KBq/m3 e entre 5 KBq/m3 e 400 KBq/m3, respectivamente, para a Fácies Principal e a Fácies de Borda do Maciço Sienítico Piquiri. A partir dos resultados de concentração de Rn no ar dos solos e de analise de estruturas, conclui-se que a zona Norte e Sul da Fácies Principal do Maciço Sienítico Piquiri, representam áreas com maior concentração de Rn e, consequentemente, com maior risco de incidência de câncer de pulmão para os habitantes.Indoor radon concentration is strongly related to the uranium concentration in rocks. The Piquiri Syenite Massif represents a syenitic rock complex with high uranium concentrations related to accessory minerals as zircon, sphene, apatite, and others. The main aim of this study was to perform radiometric measurements and determine the Rn concentration in soils of the Piquiri Syenite Massif region, in order to better evaluate the risk to the health of inhabitants who live in this area. To perform radiometric measurements was made a grid with squares of 4 km2 area, measuring in situ the counts per second, dose rate, potassium concentration, equivalent uranium concentration and equivalent thorium concentration, using the gamma spectrometer RS-125. On the other hand, it was used AlphaGUARD equipment to measure in situ of Rn concentrations in soil air of the region, locating sampling points according to the same grid and concentrating were the radiometric measurements were higher. The cps values obtained in this study range from 130 to 1045, the dose, range from 28.9 nSv/h to 424.6 nSv/h, K concentrations, from 0.5 % to 8.3 %, the eU concentrations, from 0.8 ppm to 25.8 ppm, and eTh concentrations, from 3.0 ppm to 99.2 ppm. The map of K concentrations defines the lithological contacts of the Piquiri Syenite Massif, while the highest concentrations of eTh were found in the Main Facies, and the highest concentrations of eU were measured in the North of the Main Facies of the intrusion. The 220Rn and 222Rn concentrations range between 10 KBq/m3 and 550 KBq/m3 and between 5 KBq/m3 and 400 KBq/m3, respectively, to the Main and the Marginal Facies. From the results of Rn concentrations in soils and the analysis of structures, it was concluded that the North and South zone of the Main Facies of Piquiri Syenite Massif, possibly, represents the area with the higher concentrations of indoor Rn and, in consequence, the greatest risk of lung cancer due to this element

Espectrometria de raios gama e concentrações de radônio em solos da Região do Maciço Sienítico Piquiri, municípios de Cachoeira do Sul/Encruzilhada do Sul, RS

A concentração de radônio no interior das construções está fortemente relacionada com a concentração de urânio das rochas. O Maciço Sienítico Piquiri representa um complexo de intrusão de rochas sieníticas que apresentam altas concentrações de urânio devido a minerais acessórios como zircão, titanita, apatita e outros. O objetivo do presente estudo foi realizar medidas radiométricas e de concentração de Rn nos solos da região do Maciço Sienítico Piquiri, para entender a potencialidade de risco para a saúde das pessoas que vivem nesta região. Para realizar as medidas radiométricas foi feita uma grade de quadrículas de 4 Km2 de área, usando o equipamento RS-125 para medir in situ e obter resultados de contagem por segundo, taxa de dose, concentração de potássio, concentração de equivalente-urânio e concentração de equivalente-tório. Por outro lado, foi utilizado o equipamento AlphaGUARD para fazer medições in situ de concentração de Rn no ar dos solos da região, concentrando os pontos de amostragem nas áreas de maiores valores de medidas radiométricas. Os valores de cps obtidos neste estudo variam entre 130 e 1045, os de taxa de dose, entre 28,9 nSv/h e 424,6 nSv/h, as concentrações de K, entre 0,5 % e 8,3 %, as concentrações de eU, entre 0,8 ppm e 25,8 ppm, e as concentrações de eTh, entre 3,0 ppm e 99,2 ppm. A distribuição de K delimita os contatos litológicos do Maciço sienítico Piquiri, enquanto as maiores concentrações de eTh estão na Fácies Principal do sienito, e as maiores concentrações de eU foram medidas na zona norte da Fácies Principal da intrusão. Os resultados de 220Rn e 222Rn variam entre 10 KBq/m3 e 550 KBq/m3 e entre 5 KBq/m3 e 400 KBq/m3, respectivamente, para a Fácies Principal e a Fácies de Borda do Maciço Sienítico Piquiri. A partir dos resultados de concentração de Rn no ar dos solos e de analise de estruturas, conclui-se que a zona Norte e Sul da Fácies Principal do Maciço Sienítico Piquiri, representam áreas com maior concentração de Rn e, consequentemente, com maior risco de incidência de câncer de pulmão para os habitantes.Indoor radon concentration is strongly related to the uranium concentration in rocks. The Piquiri Syenite Massif represents a syenitic rock complex with high uranium concentrations related to accessory minerals as zircon, sphene, apatite, and others. The main aim of this study was to perform radiometric measurements and determine the Rn concentration in soils of the Piquiri Syenite Massif region, in order to better evaluate the risk to the health of inhabitants who live in this area. To perform radiometric measurements was made a grid with squares of 4 km2 area, measuring in situ the counts per second, dose rate, potassium concentration, equivalent uranium concentration and equivalent thorium concentration, using the gamma spectrometer RS-125. On the other hand, it was used AlphaGUARD equipment to measure in situ of Rn concentrations in soil air of the region, locating sampling points according to the same grid and concentrating were the radiometric measurements were higher. The cps values obtained in this study range from 130 to 1045, the dose, range from 28.9 nSv/h to 424.6 nSv/h, K concentrations, from 0.5 % to 8.3 %, the eU concentrations, from 0.8 ppm to 25.8 ppm, and eTh concentrations, from 3.0 ppm to 99.2 ppm. The map of K concentrations defines the lithological contacts of the Piquiri Syenite Massif, while the highest concentrations of eTh were found in the Main Facies, and the highest concentrations of eU were measured in the North of the Main Facies of the intrusion. The 220Rn and 222Rn concentrations range between 10 KBq/m3 and 550 KBq/m3 and between 5 KBq/m3 and 400 KBq/m3, respectively, to the Main and the Marginal Facies. From the results of Rn concentrations in soils and the analysis of structures, it was concluded that the North and South zone of the Main Facies of Piquiri Syenite Massif, possibly, represents the area with the higher concentrations of indoor Rn and, in consequence, the greatest risk of lung cancer due to this element

Espectrometria de raios gama e concentrações de radônio em solos da Região do Maciço Sienítico Piquiri, municípios de Cachoeira do Sul/Encruzilhada do Sul, RS

A concentração de radônio no interior das construções está fortemente relacionada com a concentração de urânio das rochas. O Maciço Sienítico Piquiri representa um complexo de intrusão de rochas sieníticas que apresentam altas concentrações de urânio devido a minerais acessórios como zircão, titanita, apatita e outros. O objetivo do presente estudo foi realizar medidas radiométricas e de concentração de Rn nos solos da região do Maciço Sienítico Piquiri, para entender a potencialidade de risco para a saúde das pessoas que vivem nesta região. Para realizar as medidas radiométricas foi feita uma grade de quadrículas de 4 Km2 de área, usando o equipamento RS-125 para medir in situ e obter resultados de contagem por segundo, taxa de dose, concentração de potássio, concentração de equivalente-urânio e concentração de equivalente-tório. Por outro lado, foi utilizado o equipamento AlphaGUARD para fazer medições in situ de concentração de Rn no ar dos solos da região, concentrando os pontos de amostragem nas áreas de maiores valores de medidas radiométricas. Os valores de cps obtidos neste estudo variam entre 130 e 1045, os de taxa de dose, entre 28,9 nSv/h e 424,6 nSv/h, as concentrações de K, entre 0,5 % e 8,3 %, as concentrações de eU, entre 0,8 ppm e 25,8 ppm, e as concentrações de eTh, entre 3,0 ppm e 99,2 ppm. A distribuição de K delimita os contatos litológicos do Maciço sienítico Piquiri, enquanto as maiores concentrações de eTh estão na Fácies Principal do sienito, e as maiores concentrações de eU foram medidas na zona norte da Fácies Principal da intrusão. Os resultados de 220Rn e 222Rn variam entre 10 KBq/m3 e 550 KBq/m3 e entre 5 KBq/m3 e 400 KBq/m3, respectivamente, para a Fácies Principal e a Fácies de Borda do Maciço Sienítico Piquiri. A partir dos resultados de concentração de Rn no ar dos solos e de analise de estruturas, conclui-se que a zona Norte e Sul da Fácies Principal do Maciço Sienítico Piquiri, representam áreas com maior concentração de Rn e, consequentemente, com maior risco de incidência de câncer de pulmão para os habitantes.Indoor radon concentration is strongly related to the uranium concentration in rocks. The Piquiri Syenite Massif represents a syenitic rock complex with high uranium concentrations related to accessory minerals as zircon, sphene, apatite, and others. The main aim of this study was to perform radiometric measurements and determine the Rn concentration in soils of the Piquiri Syenite Massif region, in order to better evaluate the risk to the health of inhabitants who live in this area. To perform radiometric measurements was made a grid with squares of 4 km2 area, measuring in situ the counts per second, dose rate, potassium concentration, equivalent uranium concentration and equivalent thorium concentration, using the gamma spectrometer RS-125. On the other hand, it was used AlphaGUARD equipment to measure in situ of Rn concentrations in soil air of the region, locating sampling points according to the same grid and concentrating were the radiometric measurements were higher. The cps values obtained in this study range from 130 to 1045, the dose, range from 28.9 nSv/h to 424.6 nSv/h, K concentrations, from 0.5 % to 8.3 %, the eU concentrations, from 0.8 ppm to 25.8 ppm, and eTh concentrations, from 3.0 ppm to 99.2 ppm. The map of K concentrations defines the lithological contacts of the Piquiri Syenite Massif, while the highest concentrations of eTh were found in the Main Facies, and the highest concentrations of eU were measured in the North of the Main Facies of the intrusion. The 220Rn and 222Rn concentrations range between 10 KBq/m3 and 550 KBq/m3 and between 5 KBq/m3 and 400 KBq/m3, respectively, to the Main and the Marginal Facies. From the results of Rn concentrations in soils and the analysis of structures, it was concluded that the North and South zone of the Main Facies of Piquiri Syenite Massif, possibly, represents the area with the higher concentrations of indoor Rn and, in consequence, the greatest risk of lung cancer due to this element