Land degradation by soil erosion is one of the most severe environmental issues that is greatly dependent on land use management. In this study, the effects of long-term land use management (including annual cultivated field (ACF), fallow field (FF), rangeland (R), and orchard field (OF)), soil depth (0–10 and 10–20 cm), and soil organic matter content (SOM) on wind- and water-erosion indices were investigated in calcareous soils of southern Iran. Soil samples were collected from four above-mentioned land-use types, and some soil properties and erosion indices were measured. Results showed that the most of soil aggregates stability indices in the surface layer (0–10 cm) of OF were higher than those in ACF, FF, and R, respectively, by nearly 39%, 32%, and 47% for dry mean weight diameter of aggregates (MWDdry); 10%, 10%, and 48% for dry geometric mean weight diameter of aggregates (GMDdry); 21%, 17%, and 15% for water-stable aggregates (WSA); and 11%, 16%, and 31% for aggregate stability index (ASI). Moreover, the mean of the soil wind erosion indicators in OF (0–10 cm) were lower than those in ACF, FF, and R, respectively, by nearly 18%, 24%, and 26%, for wind-erodible fraction (EF); 43%, 38%, and 49% for soil erodibility to wind erosion (K); and 36%, 32%, and 41% for wind erosion rate (ER). In ACF, despite the high clay content, some aggregate stability indices such as MWoDdry and WSA were the lowest among studied land-use types which showed the negative effects of conventional tillage practices. Depth factor had only a significant effect on dust emission potential (DEP) in ACF, FF, and OF. In addition, there were significant and strong correlations between SOM and MWDdry (r = 0.79), WSA (r = 0.77), EF (r = −0.85), K (r = 0.74), and ER (r = 0.74) in all datasets.
{"title":"Soil Sensitivity to Wind and Water Erosion as Affected by Land Use in Southern Iran","authors":"H. Mozaffari, M. Rezaei, Yaser Ostovari","doi":"10.3390/EARTH2020017","DOIUrl":"https://doi.org/10.3390/EARTH2020017","url":null,"abstract":"Land degradation by soil erosion is one of the most severe environmental issues that is greatly dependent on land use management. In this study, the effects of long-term land use management (including annual cultivated field (ACF), fallow field (FF), rangeland (R), and orchard field (OF)), soil depth (0–10 and 10–20 cm), and soil organic matter content (SOM) on wind- and water-erosion indices were investigated in calcareous soils of southern Iran. Soil samples were collected from four above-mentioned land-use types, and some soil properties and erosion indices were measured. Results showed that the most of soil aggregates stability indices in the surface layer (0–10 cm) of OF were higher than those in ACF, FF, and R, respectively, by nearly 39%, 32%, and 47% for dry mean weight diameter of aggregates (MWDdry); 10%, 10%, and 48% for dry geometric mean weight diameter of aggregates (GMDdry); 21%, 17%, and 15% for water-stable aggregates (WSA); and 11%, 16%, and 31% for aggregate stability index (ASI). Moreover, the mean of the soil wind erosion indicators in OF (0–10 cm) were lower than those in ACF, FF, and R, respectively, by nearly 18%, 24%, and 26%, for wind-erodible fraction (EF); 43%, 38%, and 49% for soil erodibility to wind erosion (K); and 36%, 32%, and 41% for wind erosion rate (ER). In ACF, despite the high clay content, some aggregate stability indices such as MWoDdry and WSA were the lowest among studied land-use types which showed the negative effects of conventional tillage practices. Depth factor had only a significant effect on dust emission potential (DEP) in ACF, FF, and OF. In addition, there were significant and strong correlations between SOM and MWDdry (r = 0.79), WSA (r = 0.77), EF (r = −0.85), K (r = 0.74), and ER (r = 0.74) in all datasets.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123833538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Thakuri, Furbe Lama, R. Malla, Nitesh Khadka, N. Ghimire, F. Salerno
Lake evolution and its changes over time are an evident and easily measurable signal of human activities and climate change impacts in mountain regions. This study presents bathymetric modeling of permanent lakes (Begnas and Rara Lakes) located in two different geographic settings of Nepal. Moreover, temporal changes in land cover and soil erosion of the lake watersheds, as well as climatic trends around these lakes, are assessed. This study supports establishing reference sites for exploring scientific evidence on the impacts of anthropogenic and climate change on lake hydrological systems. Second-order polynomial models best represent the relationship between lake depth and volume. Rara Lake had a maximum depth of 169 m with an area of 10.52 km2 and a volume of 1013.305 million cubic meters (Mm3), whereas Begnas Lake had a maximum depth of 12.5 m with an area of 2.98 ± 0.10 km2 and a water volume of 13.539 Mm3 in the year 2019. Both lake regions are experiencing changes in temperature and rainfall. The area and volume of Rara Lake and its watershed have been relatively stable even with minimal land-cover change during the recent decades. Begnas Lake and its watershed have experienced significant changes in the last few decades. This study concludes that human activities in the Begnas Lake watersheds are the primary source of lake area variation rather than climate change.
{"title":"Lake Watershed Dynamics and Bathymetry Modeling of Rara and Begnas Lakes in Nepal","authors":"S. Thakuri, Furbe Lama, R. Malla, Nitesh Khadka, N. Ghimire, F. Salerno","doi":"10.3390/EARTH2020016","DOIUrl":"https://doi.org/10.3390/EARTH2020016","url":null,"abstract":"Lake evolution and its changes over time are an evident and easily measurable signal of human activities and climate change impacts in mountain regions. This study presents bathymetric modeling of permanent lakes (Begnas and Rara Lakes) located in two different geographic settings of Nepal. Moreover, temporal changes in land cover and soil erosion of the lake watersheds, as well as climatic trends around these lakes, are assessed. This study supports establishing reference sites for exploring scientific evidence on the impacts of anthropogenic and climate change on lake hydrological systems. Second-order polynomial models best represent the relationship between lake depth and volume. Rara Lake had a maximum depth of 169 m with an area of 10.52 km2 and a volume of 1013.305 million cubic meters (Mm3), whereas Begnas Lake had a maximum depth of 12.5 m with an area of 2.98 ± 0.10 km2 and a water volume of 13.539 Mm3 in the year 2019. Both lake regions are experiencing changes in temperature and rainfall. The area and volume of Rara Lake and its watershed have been relatively stable even with minimal land-cover change during the recent decades. Begnas Lake and its watershed have experienced significant changes in the last few decades. This study concludes that human activities in the Begnas Lake watersheds are the primary source of lake area variation rather than climate change.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133097579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Mikhailova, Lili Lin, Zhenbang Hao, H. Zurqani, C. Post, M. Schlautman, Gregory C. Post
Valuation of soil carbon (C) regulating ecosystem services (ES) at the state level is important for sustainable C management. The objective of this study was to assess the value of regulating ES from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for the state of New Hampshire (NH) in the United States of America (USA) by soil order and county using information from the State Soil Geographic (STATSGO) database. The total estimated monetary mid-point value for TSC stocks in the state of New Hampshire was $73.0B (i.e., 73.0 billion U.S. dollars (USD), where B = billion = 109), $64.8B for SOC stocks, and $8.1B for SIC stocks. Soil orders with the highest midpoint value for SOC were Histosols ($33.2B), Spodosols ($20.2B), and Inceptisols ($10.1B). Soil orders with the highest midpoint value for SIC were Inceptisols ($5.8B), Spodosols ($1.0B), and Entisols ($770M, where M = million = 106). Soil orders with the highest midpoint value for TSC were Histosols ($33.8B), Spodosols ($21.2B), and Inceptisols ($15.9B). The counties with the highest midpoint SOC values were Rockingham ($15.4B), Hillsborough ($9.8B), and Coos ($9.2B). The counties with the highest midpoint SIC values were Merrimack ($1.2B), Coos ($1.1B), and Rockingham ($1.0B). The counties with the highest midpoint TSC values were Rockingham ($16.5B), Hillsborough ($10.8B), and Coos ($10.3B). New Hampshire has experienced land use/land cover (LULC) changes between 2001 and 2016. The changes in LULC across the state have not been uniform, but rather have varied by county, soil order, and pre-existing land cover. The counties that have exhibited the most development (e.g., Rockingham, Hillsborough, Merrimack) are those nearest the urban center of Boston, MA. Most soil orders have experienced losses in “low disturbance” land covers (e.g., evergreen forest, hay/pasture) and gains in “high disturbance” land covers (e.g., low-, medium-, and high-intensity developed land). In particular, Histosols are a high-risk carbon “hotspot” that contributes over 50% of the total estimated sequestration of SOC in New Hampshire while covering only 7% of the total land area. Integration of pedodiversity concepts with administrative units can be useful to design soil- and land-cover specific, cost-efficient policies to manage soil C regulating ES in New Hampshire at various administrative levels.
国家层面土壤碳(C)评价对生态系统服务(ES)的调节作用对可持续碳管理具有重要意义。本研究的目的是利用STATSGO数据库的信息，基于美国新罕布什尔州(NH)土壤顺序和县避免的二氧化碳(CO2)排放社会成本的概念，评估从土壤有机碳(SOC)、土壤无机碳(SIC)和土壤总碳(TSC)储量中调节ES的价值。新罕布什尔州TSC股票的总货币中点价值估计为730亿美元(即730亿美元，其中B =十亿= 109)，SOC股票为648亿美元，SIC股票为81亿美元。土壤有机碳中点值最高的土壤目是Histosols(332亿美元)、Spodosols(202亿美元)和Inceptisols(101亿美元)。SIC中点值最高的土壤目是Inceptisols(58亿美元)、Spodosols(10亿美元)和Entisols(7.7亿美元，其中M = million = 106)。TSC中点值最高的土壤目是Histosols(338亿美元)、Spodosols(21.2亿美元)和Inceptisols(159亿美元)。SOC值中点最高的县是罗金厄姆(154亿美元)、希尔斯伯勒(98亿美元)和库斯(92亿美元)。中点SIC值最高的县是梅里马克(12亿美元)、库斯(11亿美元)和罗金厄姆(10亿美元)。TSC值中点最高的县是罗金厄姆(165亿美元)、希尔斯伯勒(108亿美元)和库斯(103亿美元)。新罕布什尔州在2001年至2016年间经历了土地利用/土地覆盖(LULC)的变化。全州LULC的变化并不是统一的，而是因县、土壤秩序和原有土地覆盖而异。发展最快的县(如罗金厄姆、希尔斯伯勒、梅里马克)是那些离马萨诸塞州波士顿市中心最近的县。大多数土壤目都经历了“低干扰”土地覆盖(如常绿森林、干草/牧场)的损失，而“高干扰”土地覆盖(如低、中、高强度开发土地)的增加。特别是，Histosols是一个高风险的碳“热点”，它贡献了新罕布什尔州SOC总估计固存量的50%以上，而只覆盖了总土地面积的7%。将土壤多样性概念与行政单位相结合，有助于设计具体的土壤和土地覆盖、具有成本效益的政策来管理土壤C，从而在新罕布什尔州的各个行政级别上调节ES。
{"title":"Vulnerability of Soil Carbon Regulating Ecosystem Services due to Land Cover Change in the State of New Hampshire, USA","authors":"E. Mikhailova, Lili Lin, Zhenbang Hao, H. Zurqani, C. Post, M. Schlautman, Gregory C. Post","doi":"10.3390/EARTH2020013","DOIUrl":"https://doi.org/10.3390/EARTH2020013","url":null,"abstract":"Valuation of soil carbon (C) regulating ecosystem services (ES) at the state level is important for sustainable C management. The objective of this study was to assess the value of regulating ES from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for the state of New Hampshire (NH) in the United States of America (USA) by soil order and county using information from the State Soil Geographic (STATSGO) database. The total estimated monetary mid-point value for TSC stocks in the state of New Hampshire was $73.0B (i.e., 73.0 billion U.S. dollars (USD), where B = billion = 109), $64.8B for SOC stocks, and $8.1B for SIC stocks. Soil orders with the highest midpoint value for SOC were Histosols ($33.2B), Spodosols ($20.2B), and Inceptisols ($10.1B). Soil orders with the highest midpoint value for SIC were Inceptisols ($5.8B), Spodosols ($1.0B), and Entisols ($770M, where M = million = 106). Soil orders with the highest midpoint value for TSC were Histosols ($33.8B), Spodosols ($21.2B), and Inceptisols ($15.9B). The counties with the highest midpoint SOC values were Rockingham ($15.4B), Hillsborough ($9.8B), and Coos ($9.2B). The counties with the highest midpoint SIC values were Merrimack ($1.2B), Coos ($1.1B), and Rockingham ($1.0B). The counties with the highest midpoint TSC values were Rockingham ($16.5B), Hillsborough ($10.8B), and Coos ($10.3B). New Hampshire has experienced land use/land cover (LULC) changes between 2001 and 2016. The changes in LULC across the state have not been uniform, but rather have varied by county, soil order, and pre-existing land cover. The counties that have exhibited the most development (e.g., Rockingham, Hillsborough, Merrimack) are those nearest the urban center of Boston, MA. Most soil orders have experienced losses in “low disturbance” land covers (e.g., evergreen forest, hay/pasture) and gains in “high disturbance” land covers (e.g., low-, medium-, and high-intensity developed land). In particular, Histosols are a high-risk carbon “hotspot” that contributes over 50% of the total estimated sequestration of SOC in New Hampshire while covering only 7% of the total land area. Integration of pedodiversity concepts with administrative units can be useful to design soil- and land-cover specific, cost-efficient policies to manage soil C regulating ES in New Hampshire at various administrative levels.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124813553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-23DOI: 10.11648/J.EARTH.20211002.11
N. Soliman, Moustafa B. Bayoumi, S. Salem
The integration of the ASTER image processing and the airborne spectrometric Gamma-Ray interpretation helped in identifying the types and illustrating the distributions of the probable sites for radioactive mineralization at the Gabal Abu Garadi area. Appling various techniques of image processing for Landsat OLI and ASTER satellite to discrimination the differently exposed rock units and extract major and minor structural lineaments. This study resulted that the ASTER VNIR-SWIR bands are effectively used for clarifying the sericite, kaolinite, chlorite, illite and hematite bearing alteration zones, whereas the ASTER TIR bands are most effective in delineation of the silica-rich zones which could be pathfinders for radioactive mineralization within the study area. The resultant alteration maps show good coincidence with the explored uranium sites and suggest further similar unexplored sites. The predominance of low eTh/eU= 1.31 indicates U mobilization and reveals that magmatic differentiation was not the sole process responsible for the concentration of these radioactive elements in the Abu Gradi area. Where the presence of adequate structures such as shear zones and fault planes facilitates the circulation of hydrothermal fluids and meteoric waters leading to mobilization and a redistribution of uranium. This paper could assist the principals of uranium exploration techniques.
ASTER图像处理和航空光谱伽玛射线解释的结合有助于确定Gabal Abu Garadi地区放射性矿化可能地点的类型和分布。应用Landsat OLI和ASTER卫星的各种图像处理技术，识别不同暴露的岩石单元，提取主要和次要的构造轮廓。研究结果表明，ASTER VNIR-SWIR波段对绢云母、高岭石、绿泥石、伊利石和赤铁矿蚀变带的澄清效果最好，而ASTER TIR波段对富硅带的圈定效果最好，富硅带可作为研究区内放射性矿化的探路者。所得到的蚀变图与已勘探的铀矿地点吻合良好，并提示进一步的类似未勘探地点。低eTh/eU= 1.31的优势表明铀的活化作用，表明岩浆分异不是造成这些放射性元素富集的唯一原因。存在适当的构造，如剪切带和断裂面，有利于热液流体和大气水的循环，导致铀的调动和再分配。本文对铀矿找矿技术的指导意义重大。
{"title":"Mapping the Alteration Zones for Uranium Exploration in Gabal Abu Garadi Area Central Eastern Desert, Egypt, Using Aster Data","authors":"N. Soliman, Moustafa B. Bayoumi, S. Salem","doi":"10.11648/J.EARTH.20211002.11","DOIUrl":"https://doi.org/10.11648/J.EARTH.20211002.11","url":null,"abstract":"The integration of the ASTER image processing and the airborne spectrometric Gamma-Ray interpretation helped in identifying the types and illustrating the distributions of the probable sites for radioactive mineralization at the Gabal Abu Garadi area. Appling various techniques of image processing for Landsat OLI and ASTER satellite to discrimination the differently exposed rock units and extract major and minor structural lineaments. This study resulted that the ASTER VNIR-SWIR bands are effectively used for clarifying the sericite, kaolinite, chlorite, illite and hematite bearing alteration zones, whereas the ASTER TIR bands are most effective in delineation of the silica-rich zones which could be pathfinders for radioactive mineralization within the study area. The resultant alteration maps show good coincidence with the explored uranium sites and suggest further similar unexplored sites. The predominance of low eTh/eU= 1.31 indicates U mobilization and reveals that magmatic differentiation was not the sole process responsible for the concentration of these radioactive elements in the Abu Gradi area. Where the presence of adequate structures such as shear zones and fault planes facilitates the circulation of hydrothermal fluids and meteoric waters leading to mobilization and a redistribution of uranium. This paper could assist the principals of uranium exploration techniques.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131790509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Amosu, Mohamed Imsalem, A. Raymond, Yuefeng Sun
Fischer plots are a technique that is used to graph changes in accommodation in cyclic carbonate successions. They typically depict the cumulative departure from the average cycle thickness as a function of the cycle number or stratigraphic depth. Many applications of Fischer plots focus on their construction from exposed cyclic carbonate successions. No published programs allow the direct construction of Fischer plots from digital wireline well-logs or dynamic presentations of Fischer plots. Here, we introduce a program known as FischerLab, which facilitates the generation and analysis of Fischer plots. In addition to accepting interpreted stratigraphic data input, FischerLab facilitates the interpretation of digital wireline logs for the generation of Fischer plots in cycle and depth domains, as well as in a dynamic evolving cycle and relative depth domain from an easy-to-use interface. The dynamic construction facilitates the correlation of specific stratigraphic packages to parts of the accommodation cycle while simultaneously tracking the locus of the mean subsidence vector. We demonstrate the use of FischerLab on data derived from the carbonate succession outcrops of the Al-Athrun Formation, Libya, and the Glen Rose Formation, Central Texas, USA, as well as on wireline well-log data from the Western Great Bahama Bank, the Bahamas.
{"title":"FischerLab: An Application for Generating Fischer Plots and Dynamic Fischer Plots from Wireline Well-Logs and Stratigraphic Data","authors":"A. Amosu, Mohamed Imsalem, A. Raymond, Yuefeng Sun","doi":"10.3390/EARTH1010004","DOIUrl":"https://doi.org/10.3390/EARTH1010004","url":null,"abstract":"Fischer plots are a technique that is used to graph changes in accommodation in cyclic carbonate successions. They typically depict the cumulative departure from the average cycle thickness as a function of the cycle number or stratigraphic depth. Many applications of Fischer plots focus on their construction from exposed cyclic carbonate successions. No published programs allow the direct construction of Fischer plots from digital wireline well-logs or dynamic presentations of Fischer plots. Here, we introduce a program known as FischerLab, which facilitates the generation and analysis of Fischer plots. In addition to accepting interpreted stratigraphic data input, FischerLab facilitates the interpretation of digital wireline logs for the generation of Fischer plots in cycle and depth domains, as well as in a dynamic evolving cycle and relative depth domain from an easy-to-use interface. The dynamic construction facilitates the correlation of specific stratigraphic packages to parts of the accommodation cycle while simultaneously tracking the locus of the mean subsidence vector. We demonstrate the use of FischerLab on data derived from the carbonate succession outcrops of the Al-Athrun Formation, Libya, and the Glen Rose Formation, Central Texas, USA, as well as on wireline well-log data from the Western Great Bahama Bank, the Bahamas.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121842038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-20DOI: 10.11648/j.earth.20200904.13
U. Khan, F. Khan, Tahirinandraina Prudence Rabemaharitra, Malik Arsalan, O. Abdul-Rahim, Inayat Ur Rahman
Gravity data indicates that there is a regular relation between crustal structure, crustal density (composition), and surface ascension. In order to delineate surface and subsurface geological structure features, and to calculate the thickness variation of the crust and sedimentary/metasedimentary wedges, integrated approach of Geographic Information System (GIS) i.e. digital elevation models (DEMs) and two-dimensional forward modeling of gravity data were utilized, which provide the best results for the primary objectives. Tectonically, the study area lies in the Lesser Himalayas as well as to an extent in the sub-Himalaya, more concretely in the western limb of Hazara Kashmir Syntaxis. Topographic data was accumulated in XYZ coordinates utilizing point heights method, and DEMs generation, manipulation, interpretation, and visualization process were directed to surfer-15 and ArcGIS software. Determinately the visualization of surface geological structure in the form of DEMs were proposed. The gravity stations in single contour mode have been quantified by using Scintrex CG-5 gravity meter. The collected gravity data was processed by standardizing corrections, two-dimensional forward modeling along with gravity profile were utilized and bouguer anomaly map and gravity model was computed utilizing bouguer density of 2.4 g/cm3, where the subsurface structures are demarcated by the bouguer anomaly and gravity model. In summary this research has allowed the validation of surface and subsurface geological structure visualization. Digital elevation models provide a defensive prediction of the geological structure of the regional surface. The gravity model demarcated a series of stratigraphic units with density boundaries within the basement. The gravity model also suggests that the thickness of sedimentary/metasedimentary wedge in Thandiani area is 11.48 km and in Boi area, the thickness elongates to about 14.43 km. The total thickness of crust in Thandiani and Boi area is 49.53 km and 52.43 km respectively.
{"title":"Surface and Crustal Study Based on Digital Elevation Modeling and 2-D Gravity Forward Modeling in Thandiani to Boi Areas of Hazara Region, Pakistan","authors":"U. Khan, F. Khan, Tahirinandraina Prudence Rabemaharitra, Malik Arsalan, O. Abdul-Rahim, Inayat Ur Rahman","doi":"10.11648/j.earth.20200904.13","DOIUrl":"https://doi.org/10.11648/j.earth.20200904.13","url":null,"abstract":"Gravity data indicates that there is a regular relation between crustal structure, crustal density (composition), and surface ascension. In order to delineate surface and subsurface geological structure features, and to calculate the thickness variation of the crust and sedimentary/metasedimentary wedges, integrated approach of Geographic Information System (GIS) i.e. digital elevation models (DEMs) and two-dimensional forward modeling of gravity data were utilized, which provide the best results for the primary objectives. Tectonically, the study area lies in the Lesser Himalayas as well as to an extent in the sub-Himalaya, more concretely in the western limb of Hazara Kashmir Syntaxis. Topographic data was accumulated in XYZ coordinates utilizing point heights method, and DEMs generation, manipulation, interpretation, and visualization process were directed to surfer-15 and ArcGIS software. Determinately the visualization of surface geological structure in the form of DEMs were proposed. The gravity stations in single contour mode have been quantified by using Scintrex CG-5 gravity meter. The collected gravity data was processed by standardizing corrections, two-dimensional forward modeling along with gravity profile were utilized and bouguer anomaly map and gravity model was computed utilizing bouguer density of 2.4 g/cm3, where the subsurface structures are demarcated by the bouguer anomaly and gravity model. In summary this research has allowed the validation of surface and subsurface geological structure visualization. Digital elevation models provide a defensive prediction of the geological structure of the regional surface. The gravity model demarcated a series of stratigraphic units with density boundaries within the basement. The gravity model also suggests that the thickness of sedimentary/metasedimentary wedge in Thandiani area is 11.48 km and in Boi area, the thickness elongates to about 14.43 km. The total thickness of crust in Thandiani and Boi area is 49.53 km and 52.43 km respectively.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124140615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-14DOI: 10.11648/j.earth.20200904.12
D. E. Andrews
The variable “∆14C”, commonly used in radiocarbon dating and tracing applications to quantify 14C levels, is a measure of the ratio of the radioisotope 14C to other carbon in a sample. After atmospheric nuclear testing in the 1950’s and 1960’s nearly doubled atmospheric 14C, the later evolution of ∆14C allowed insights into the dynamics of carbon exchange between the atmosphere and terrestrial and marine sinks. But a few authors without backgrounds in isotope measurements have confused ∆14C with excess 14C concentration. They erroneously interpret the present recovery of ∆14C to near its pre bomb test value as evidence that atmospheric 14C concentration has returned to its earlier value. From this they reach further incorrect conclusions about the fate of anthropogenic CO2 introduced into the atmosphere by fossil fuel burning. An estimate of the true time dependence of atmospheric 14C concentration over the past century, calculated from averaged atmospheric ∆14C and CO2 data is presented. The data show that 14C concentrations remain over 30% above 1950 values, and have begun to increase, even as ∆14C continues to fall. This confirms the prediction of a conventional model of the carbon cycle. The unconventional models of carbon dynamics motivated by the mistake, on the other hand, are excluded by the properly interpreted 14C data.
{"title":"Correcting an Error in Some Interpretations of Atmospheric 14C Data","authors":"D. E. Andrews","doi":"10.11648/j.earth.20200904.12","DOIUrl":"https://doi.org/10.11648/j.earth.20200904.12","url":null,"abstract":"The variable “∆14C”, commonly used in radiocarbon dating and tracing applications to quantify 14C levels, is a measure of the ratio of the radioisotope 14C to other carbon in a sample. After atmospheric nuclear testing in the 1950’s and 1960’s nearly doubled atmospheric 14C, the later evolution of ∆14C allowed insights into the dynamics of carbon exchange between the atmosphere and terrestrial and marine sinks. But a few authors without backgrounds in isotope measurements have confused ∆14C with excess 14C concentration. They erroneously interpret the present recovery of ∆14C to near its pre bomb test value as evidence that atmospheric 14C concentration has returned to its earlier value. From this they reach further incorrect conclusions about the fate of anthropogenic CO2 introduced into the atmosphere by fossil fuel burning. An estimate of the true time dependence of atmospheric 14C concentration over the past century, calculated from averaged atmospheric ∆14C and CO2 data is presented. The data show that 14C concentrations remain over 30% above 1950 values, and have begun to increase, even as ∆14C continues to fall. This confirms the prediction of a conventional model of the carbon cycle. The unconventional models of carbon dynamics motivated by the mistake, on the other hand, are excluded by the properly interpreted 14C data.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121585390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-31DOI: 10.11648/j.earth.20200904.11
H. Abdussamatov
The climate system depends at an extremely complex set of long-term (about 30 years or more) physical processes in the ocean-land-atmosphere systems, which, in turn, are influenced mainly quasi-bicentennial variations of the total solar irradiance (TSI). The TSI decline phase started around 1990. The onset of the Grand minimum phase of the TSI quasi-bicentennial cycle of the Maunder type is predicted in the 27th ±1 cycle in 2043±11. Long period of deficiency of absorbed solar energy since about 1990 was not compensated by a decrease in the Earth’s thermal energy emitted into space, since it does not have time to cool down due to thermal inertia, and it continues to radiate heat in the same high volumes. Solar cooling has started. As a result, the Earth has, and will continue to have, a long negative energy balance, which will ensure a slight decrease in temperature. However, this slight decrease in temperature is extremely important as a trigger mechanism for the subsequent chain effects of secondary causal effects of feedback that will greatly enhance the cooling. This will certainly lead to the onset of a phase of deep cooling of the climate approximately in the year 2070±11. The temperature is always cooler (with some time delay) in the during long-term periods of TSI decline phase of the TSI quasi-bicentennial cycle and warmer in the during periods of its growth phase. The climate sensitivity to the atmospheric carbon dioxide abundance, due to the significant overlap of the spectral absorption bands of the water vapor and carbon dioxide, decreases as a result of a significant increase in the concentration of water vapor directly in the near-surface layer of the troposphere during warming. The impact of a long-term cloud coverage growth on climate change is also virtually nonexistent.
{"title":"Energy Imbalance Between the Earth and Space Controls the Climate","authors":"H. Abdussamatov","doi":"10.11648/j.earth.20200904.11","DOIUrl":"https://doi.org/10.11648/j.earth.20200904.11","url":null,"abstract":"The climate system depends at an extremely complex set of long-term (about 30 years or more) physical processes in the ocean-land-atmosphere systems, which, in turn, are influenced mainly quasi-bicentennial variations of the total solar irradiance (TSI). The TSI decline phase started around 1990. The onset of the Grand minimum phase of the TSI quasi-bicentennial cycle of the Maunder type is predicted in the 27th ±1 cycle in 2043±11. Long period of deficiency of absorbed solar energy since about 1990 was not compensated by a decrease in the Earth’s thermal energy emitted into space, since it does not have time to cool down due to thermal inertia, and it continues to radiate heat in the same high volumes. Solar cooling has started. As a result, the Earth has, and will continue to have, a long negative energy balance, which will ensure a slight decrease in temperature. However, this slight decrease in temperature is extremely important as a trigger mechanism for the subsequent chain effects of secondary causal effects of feedback that will greatly enhance the cooling. This will certainly lead to the onset of a phase of deep cooling of the climate approximately in the year 2070±11. The temperature is always cooler (with some time delay) in the during long-term periods of TSI decline phase of the TSI quasi-bicentennial cycle and warmer in the during periods of its growth phase. The climate sensitivity to the atmospheric carbon dioxide abundance, due to the significant overlap of the spectral absorption bands of the water vapor and carbon dioxide, decreases as a result of a significant increase in the concentration of water vapor directly in the near-surface layer of the troposphere during warming. The impact of a long-term cloud coverage growth on climate change is also virtually nonexistent.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"360 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134409613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-29DOI: 10.11648/J.EARTH.20200903.13
A. A. El-Gawad
The cement industry depends essentially on the clay as one of the main raw materials for the industry. The Tourah clay quarry is one of the oldest and largest quarries of clays in Egypt, which is located to the southeastern of Cairo. The biggest problems that affect the clay quarries and may cause them to be closed forever is that, the water reaches them and leads to the difficulty of extracting raw materials from the quarries and ultimately leads to their closure. During the mining operations and extraction of raw materials from the extension of Tourah clay quarry, a water leak was observed that reached the bottom of the quarry, and the water began to increase and led to the difficulty of entering and exiting the equipments from the quarry. A detailed geological field study and geoelectrical resistivity survey were conducted in and around the extension of Tourah clay quarry to find out the source and cause of the water leak, which was increasing rapidly on the bottom of quarry. A geoelectrical resistivity survey was performed in the form of thirteen vertical electrical soundings and two horizontal profiling were made using the Wenner configuration in order to understand and solve the formentioned problem. The interpretation of the geoelectrical data shows three main units; surface layer from dry sand, gravel and rock fragments followed by a second layer of loose sand and is partially saturated with water and finally a clay layer which is extracted as a raw material in cement industry. Accordingly, based on the field geological observations in addition to the geoelectrical resistivity interpretations, we can conclude that, the possible water source in the bottom of clay quarry is due to the second loose partially saturated sand unit and the direction of water invasion in this particular area comes from the northeastern direction. To save the extension of Tourah clay quarry from closure it is recommended to extract the water from the sand unit before it reached the quarry bottom either by water head compensation or dewatering of the well field area.
{"title":"Water Seepage Source at the Extension of Tourah Clay Quarry, Southeastern Cairo Based on Geological and Geoelectrical Resistivity Measurements","authors":"A. A. El-Gawad","doi":"10.11648/J.EARTH.20200903.13","DOIUrl":"https://doi.org/10.11648/J.EARTH.20200903.13","url":null,"abstract":"The cement industry depends essentially on the clay as one of the main raw materials for the industry. The Tourah clay quarry is one of the oldest and largest quarries of clays in Egypt, which is located to the southeastern of Cairo. The biggest problems that affect the clay quarries and may cause them to be closed forever is that, the water reaches them and leads to the difficulty of extracting raw materials from the quarries and ultimately leads to their closure. During the mining operations and extraction of raw materials from the extension of Tourah clay quarry, a water leak was observed that reached the bottom of the quarry, and the water began to increase and led to the difficulty of entering and exiting the equipments from the quarry. A detailed geological field study and geoelectrical resistivity survey were conducted in and around the extension of Tourah clay quarry to find out the source and cause of the water leak, which was increasing rapidly on the bottom of quarry. A geoelectrical resistivity survey was performed in the form of thirteen vertical electrical soundings and two horizontal profiling were made using the Wenner configuration in order to understand and solve the formentioned problem. The interpretation of the geoelectrical data shows three main units; surface layer from dry sand, gravel and rock fragments followed by a second layer of loose sand and is partially saturated with water and finally a clay layer which is extracted as a raw material in cement industry. Accordingly, based on the field geological observations in addition to the geoelectrical resistivity interpretations, we can conclude that, the possible water source in the bottom of clay quarry is due to the second loose partially saturated sand unit and the direction of water invasion in this particular area comes from the northeastern direction. To save the extension of Tourah clay quarry from closure it is recommended to extract the water from the sand unit before it reached the quarry bottom either by water head compensation or dewatering of the well field area.","PeriodicalId":350455,"journal":{"name":"Eearth","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126548278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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