Pub Date : 2020-12-04DOI: 10.15625/0866-7187/15571
Nguyễn Ngọc Lâu, R. Coleman, Ha Minh Hoa
Determining the speed of tectonic plate displacement helps us to better understand tectonic activities of the area, and is a prerequisite to help forecast earthquakes. The determination of tectonic plate displacement by GNSS technology in Vietnam has been conducted since the 2000s, mainly using the relative positioning technique. The increasing accuracy of precise point positioning technique, and the number of CORS in Vietnam, will facilitate the accurate determination of tectonic velocities. Based on the GNSS data of some CORSs in Vietnam from 2016-2018, we have determined accurately their three-dimensional coordinates using a precise point positioning technique. After modeling periodic variations on the time series, we calculated the tectonic movement rate of 7 Vietnamese stations and 3 other stations in the region. Through analysis and comparison with other geology/plate motion models and GPS results, we conclude that this result is reliable. The velocity of tectonic motion in the North, East and Up components of Ha Noi, Da Nang and Ho Chi Minh City are respectively (-13.1, +32.8, -1.3), (-9.9, +31.0, +2.6) and (-10.3, +26.9, +2.7) mm/year.
{"title":"Determination of tectonic velocities of some continuously operating reference stations (CORS) in Vietnam 2016-2018 by using precise point positioning","authors":"Nguyễn Ngọc Lâu, R. Coleman, Ha Minh Hoa","doi":"10.15625/0866-7187/15571","DOIUrl":"https://doi.org/10.15625/0866-7187/15571","url":null,"abstract":"Determining the speed of tectonic plate displacement helps us to better understand tectonic activities of the area, and is a prerequisite to help forecast earthquakes. The determination of tectonic plate displacement by GNSS technology in Vietnam has been conducted since the 2000s, mainly using the relative positioning technique. The increasing accuracy of precise point positioning technique, and the number of CORS in Vietnam, will facilitate the accurate determination of tectonic velocities. Based on the GNSS data of some CORSs in Vietnam from 2016-2018, we have determined accurately their three-dimensional coordinates using a precise point positioning technique. After modeling periodic variations on the time series, we calculated the tectonic movement rate of 7 Vietnamese stations and 3 other stations in the region. Through analysis and comparison with other geology/plate motion models and GPS results, we conclude that this result is reliable. The velocity of tectonic motion in the North, East and Up components of Ha Noi, Da Nang and Ho Chi Minh City are respectively (-13.1, +32.8, -1.3), (-9.9, +31.0, +2.6) and (-10.3, +26.9, +2.7) mm/year.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":"43 1","pages":"1-12"},"PeriodicalIF":1.5,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42049797","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 : 2020-12-04DOI: 10.15625/0866-7187/15573
M. Rodkin, Ngo Thi Lu, S. Punanova
The trace element (TE) content of oils is known to have a polygenetic character and to be inherited from an organic matter, surrounding rocks and from formation waters. The presence of some TEs indicates the involvement of the deep source, at least from the Lower Crust. However, these conclusions have a qualitative character. We present the results of the correlation analysis of TE content of oils with the chemical compositions of the Upper, Middle, and Lower Crust, with different types of organic matter, clays, and causetobiolites. A logarithmic instead of a linear scale for TE concentration values are used in calculations because the examining values change by several orders of magnitude. The TE compositions of clays, coals, and shales correlate better with the composition of the upper continental crust and an organic matter. In contrast, the TE contents in the majority of oils correlate stronger with the Lower crust, which indicates a significant contribution from the Lower continental crust. This finding points to the role that the uprising flow of fluid plays in the process of the formation of oil. Only young oils from Kamchatka and from White Tiger huge oil fields indicate a better correlation with the Upper crust. This finding is explained by the lower depth of formation of the uprising flow of deep waters because of higher deep temperatures in Kamchatka and in the White Tiger oil field area. The obtained trend of change of TE content in clays and different caustobiolites oils including is interpreted as a mixing line between the subsurface end member (which is characterized by high correlation with the chemical content of the Upper crust and biota) and the deep end member (high correlation with the chemical content of the Lower crust).
{"title":"Correlation of trace element composition of oils and other caustobiolites with chemical content of different types of biota and the Upper, Middle and the Lower Earth's Crust","authors":"M. Rodkin, Ngo Thi Lu, S. Punanova","doi":"10.15625/0866-7187/15573","DOIUrl":"https://doi.org/10.15625/0866-7187/15573","url":null,"abstract":"The trace element (TE) content of oils is known to have a polygenetic character and to be inherited from an organic matter, surrounding rocks and from formation waters. The presence of some TEs indicates the involvement of the deep source, at least from the Lower Crust. However, these conclusions have a qualitative character. We present the results of the correlation analysis of TE content of oils with the chemical compositions of the Upper, Middle, and Lower Crust, with different types of organic matter, clays, and causetobiolites. A logarithmic instead of a linear scale for TE concentration values are used in calculations because the examining values change by several orders of magnitude. The TE compositions of clays, coals, and shales correlate better with the composition of the upper continental crust and an organic matter. In contrast, the TE contents in the majority of oils correlate stronger with the Lower crust, which indicates a significant contribution from the Lower continental crust. This finding points to the role that the uprising flow of fluid plays in the process of the formation of oil. Only young oils from Kamchatka and from White Tiger huge oil fields indicate a better correlation with the Upper crust. This finding is explained by the lower depth of formation of the uprising flow of deep waters because of higher deep temperatures in Kamchatka and in the White Tiger oil field area. The obtained trend of change of TE content in clays and different caustobiolites oils including is interpreted as a mixing line between the subsurface end member (which is characterized by high correlation with the chemical content of the Upper crust and biota) and the deep end member (high correlation with the chemical content of the Lower crust).","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":"43 1","pages":"23-32"},"PeriodicalIF":1.5,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49220797","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 : 2020-12-04DOI: 10.15625/0866-7187/15704
L. Nguyen, H. Van, Quang Trung Nguyen, Thu Huong Nguyen, Thi Bich Lien Nguyen, T. Pham, Thai-Hoang Le, Manh-Ha Bui, Ordanza Hanna Joy Tilpo, Marcaida Gio Serafin Ivan Jimenez, T. Ngo
In this work, paper waste sludge (PWS) collected from the primary settling tank of the paper wastewater treatment plant was utilized to generate hydrochar as a low-cost adsorbent for removal of Cr(VI) from aqueous solution. The characteristics of paper waste sludge hydrochar (PWSH) and the effects of adsorption conditions of Cr(VI) onto PWSH, including solution pH (3-9), contact time (5-240 min), initial Cr(VI) concentration (10-80 mg/L) and the adsorbent dose of 1 g/L at room temperature (25±2°C) were investigated. Adsorption isotherm and kinetics were also predicted in this work. The results indicate that the maximum adsorption capacity achieved 11.89 mg/g at 120 min of contact time, pH 3, and initial Cr(VI) concentration of 60 mg/L. The adsorption isotherm was reflected the best by the Langmuir model (R2 of 0.9968). Whereas, the adsorption kinetic also indicates that the pseudo-second-order model predicted the best for Cr(VI) adsorption process with a R2 of 0.9469. The mechanism of Cr(VI) adsorption process onto PWSH was chemical sorption through electrostatic interaction and ion exchange.
{"title":"Removal of chromium from wastewater using paper waste sludge-derived hyrdrochar modified by naoh","authors":"L. Nguyen, H. Van, Quang Trung Nguyen, Thu Huong Nguyen, Thi Bich Lien Nguyen, T. Pham, Thai-Hoang Le, Manh-Ha Bui, Ordanza Hanna Joy Tilpo, Marcaida Gio Serafin Ivan Jimenez, T. Ngo","doi":"10.15625/0866-7187/15704","DOIUrl":"https://doi.org/10.15625/0866-7187/15704","url":null,"abstract":"In this work, paper waste sludge (PWS) collected from the primary settling tank of the paper wastewater treatment plant was utilized to generate hydrochar as a low-cost adsorbent for removal of Cr(VI) from aqueous solution. The characteristics of paper waste sludge hydrochar (PWSH) and the effects of adsorption conditions of Cr(VI) onto PWSH, including solution pH (3-9), contact time (5-240 min), initial Cr(VI) concentration (10-80 mg/L) and the adsorbent dose of 1 g/L at room temperature (25±2°C) were investigated. Adsorption isotherm and kinetics were also predicted in this work. The results indicate that the maximum adsorption capacity achieved 11.89 mg/g at 120 min of contact time, pH 3, and initial Cr(VI) concentration of 60 mg/L. The adsorption isotherm was reflected the best by the Langmuir model (R2 of 0.9968). Whereas, the adsorption kinetic also indicates that the pseudo-second-order model predicted the best for Cr(VI) adsorption process with a R2 of 0.9469. The mechanism of Cr(VI) adsorption process onto PWSH was chemical sorption through electrostatic interaction and ion exchange.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":"43 1","pages":"70-79"},"PeriodicalIF":1.5,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43635982","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 : 2020-12-04DOI: 10.15625/0866-7187/15701
A. Reed, L. Koroznikova, M. Khandelwal
This paper presents the viability study of utilising a rod or ball mill to grind a ‘5 mm grit’ to 100% passing 2.36 mm and fit in with a desired particle size analysis. The aim is to introduce this grit into the concrete grade sand produced at the Hanson owned Axedale Sand & Gravel quarry to reduce generated waste and improve the process efficiency. A ball mill and rod mill were used to grind the samples at an interval of 5 and 10 minutes. From the laboratory experimental analysis, it was found that a ball mill with 5 minutes grinding time in closed-circuit using a classifier to remove undersize and reintroduce oversize to the mill would be a viable option in an industrial setting. A Bond Ball Mill Grindability Test was undertaken to determine the grindability of the 5 mm grit, which served to determine the power (kWh/t) required to grind it to 100% passing 2.36 mm. The bond ball mill grindability test showed that the grit had a work index value of 17.66 kWh/t. This work index gives an actual work input of 13.54 kWh/t, meaning that for every ton of feed material introduced to the mill, 13.54 kWh of work input is required to grind it to 150 microns.
{"title":"A case study of grinding coarse 5 mm particles into sand grade particles less than 2.36 mm","authors":"A. Reed, L. Koroznikova, M. Khandelwal","doi":"10.15625/0866-7187/15701","DOIUrl":"https://doi.org/10.15625/0866-7187/15701","url":null,"abstract":"This paper presents the viability study of utilising a rod or ball mill to grind a ‘5 mm grit’ to 100% passing 2.36 mm and fit in with a desired particle size analysis. The aim is to introduce this grit into the concrete grade sand produced at the Hanson owned Axedale Sand & Gravel quarry to reduce generated waste and improve the process efficiency. A ball mill and rod mill were used to grind the samples at an interval of 5 and 10 minutes. From the laboratory experimental analysis, it was found that a ball mill with 5 minutes grinding time in closed-circuit using a classifier to remove undersize and reintroduce oversize to the mill would be a viable option in an industrial setting. A Bond Ball Mill Grindability Test was undertaken to determine the grindability of the 5 mm grit, which served to determine the power (kWh/t) required to grind it to 100% passing 2.36 mm. The bond ball mill grindability test showed that the grit had a work index value of 17.66 kWh/t. This work index gives an actual work input of 13.54 kWh/t, meaning that for every ton of feed material introduced to the mill, 13.54 kWh of work input is required to grind it to 150 microns.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":"43 1","pages":"56-69"},"PeriodicalIF":1.5,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46612057","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 : 2020-12-04DOI: 10.15625/0866-7187/15720
P. T. Dung, T. Anh, T. Q. Hùng, Trang Trong Hoa, R. Shelepaev, N. Hoang, T. Công
The pegmatoid intrusions of the Nui Chua complex are one of the important mafic-ultramafic intrusive series associated with Fe-Ti-V ores in northern Vietnam. These intrusions consist of plagiowebsterite, clinopyroxenite, melanogabbronorite, mesogabbro, gabbronorite, and leucogabbronorite. The Fe-Ti oxide ores being massive or disseminated appear layered or veined in pegmatoid rocks. The geochemical characteristics of pegmatoid rocks are rich in Fe, Ti, V and poor Mg; their HREE are higher than LREE, with [La/Yb]N of 0.49 to 0.91 (average: 0.67), showing negative anomalies at Nb, Ta, Th, U, Sr, Zr and positive anomalies at Cs, Ti, and K. The chemical composition and distribution characteristics of trace and rare earth elements of mafic and ultramafic rocks show that they share the same magma source. Having the same geochemical tendency of intrusive formations, Fe-Ti oxide ores are magmatic origin associated with intrusive pegmatoid rocks. The pegmatoid rocks of the Nui Chua complex and Fe-Ti oxide ores are formed as a product of the fractional crystallization of Fe-Ti-rich residual melts after crystallization of the layered rocks.
{"title":"Petrographic and geochemical characteristics of the Nui Chua pegmatoid mafic-ultramafic series, Northern Vietnam: Significance in petrogenesis and Fe-Ti-V metallogenesis","authors":"P. T. Dung, T. Anh, T. Q. Hùng, Trang Trong Hoa, R. Shelepaev, N. Hoang, T. Công","doi":"10.15625/0866-7187/15720","DOIUrl":"https://doi.org/10.15625/0866-7187/15720","url":null,"abstract":"The pegmatoid intrusions of the Nui Chua complex are one of the important mafic-ultramafic intrusive series associated with Fe-Ti-V ores in northern Vietnam. These intrusions consist of plagiowebsterite, clinopyroxenite, melanogabbronorite, mesogabbro, gabbronorite, and leucogabbronorite. The Fe-Ti oxide ores being massive or disseminated appear layered or veined in pegmatoid rocks. The geochemical characteristics of pegmatoid rocks are rich in Fe, Ti, V and poor Mg; their HREE are higher than LREE, with [La/Yb]N of 0.49 to 0.91 (average: 0.67), showing negative anomalies at Nb, Ta, Th, U, Sr, Zr and positive anomalies at Cs, Ti, and K. The chemical composition and distribution characteristics of trace and rare earth elements of mafic and ultramafic rocks show that they share the same magma source. Having the same geochemical tendency of intrusive formations, Fe-Ti oxide ores are magmatic origin associated with intrusive pegmatoid rocks. The pegmatoid rocks of the Nui Chua complex and Fe-Ti oxide ores are formed as a product of the fractional crystallization of Fe-Ti-rich residual melts after crystallization of the layered rocks.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42838464","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 : 2020-09-14DOI: 10.15625/0866-7187/42/4/15430
Tran Thi Man, Tran Thi Be Lan, N. A. Duong, Phan Lưu Anh
The study was carried out to assess the suitability of Tam Bo bentonite for application in peloid. By using the XRD analysis method, the results showed that the mineral component of Tam Bo bentonite was mainly smectite (montmorillonite) (55–73%), illite (10-14%), quartz (10–16%), and minor minerals such as siderite, feldspar, goethite, chlorite and kaolinite. Chemical composition of the samples analyzed by the XRF method composed of a high amount of SiO2 (51.38–55.16%) and Fe2O3 (5.31–7.97%), low content of Al2O3 (14.58–20.87%), and the other oxides with low content. The analysis result using the ICP-OES method indicated that bentonites in Tam Bo consisted of trace elements such as As, Ba, Cr, Cd, Co, Cu, La, La, Pb, Sb, Sc, V, Zn, and their content is similar to the values in peloid for the commercial use. Tam Bo bentonite has a pH value of 8.17, a very high CEC index (71 mg/100g), a plasticity index of 28%, expandability of 70%. All of the samples did not contain pathogenic bacteria. The study result confirms that Tam Bo bentonite responses to the criteria for making the peloid and similar to the peloids of Vale das Furnas (in Portugal), Calda (in Italy), Archena (in Spain).
本研究旨在评估Tam Bo膨润土在peloid中的适用性。采用XRD分析方法，结果表明，Bo膨润土的矿物成分主要为蒙脱石（蒙脱石）（55-73%）、伊利石（10-14%）、石英（10-16%），以及菱铁矿、长石、针铁矿、绿泥石、高岭石等少量矿物。XRF法分析的样品化学成分由大量SiO2（51.38–55.16%）和Fe2O3（5.31–7.97%）、低含量Al2O3（14.58–20.87%）和其他低含量氧化物组成。采用ICP-OES法分析结果表明，Tam Bo膨润土中含有as、Ba、Cr、Cd、Co、Cu、La、La、Pb、Sb、Sc、V、Zn等微量元素，其含量与工业用peloid中的含量相似。Tam Bo膨润土的pH值为8.17，CEC指数非常高（71mg/100g），塑性指数为28%，膨胀性为70%。所有样本均不含致病菌。研究结果证实，Tam Bo膨润土符合制作球粒的标准，类似于Vale das Furnas（葡萄牙）、Calda（意大利）和Archena（西班牙）的球粒。
{"title":"Assessment of the usability of Tam Bo bentonite (Di Linh - Lam Dong) for peloid","authors":"Tran Thi Man, Tran Thi Be Lan, N. A. Duong, Phan Lưu Anh","doi":"10.15625/0866-7187/42/4/15430","DOIUrl":"https://doi.org/10.15625/0866-7187/42/4/15430","url":null,"abstract":"The study was carried out to assess the suitability of Tam Bo bentonite for application in peloid. By using the XRD analysis method, the results showed that the mineral component of Tam Bo bentonite was mainly smectite (montmorillonite) (55–73%), illite (10-14%), quartz (10–16%), and minor minerals such as siderite, feldspar, goethite, chlorite and kaolinite. Chemical composition of the samples analyzed by the XRF method composed of a high amount of SiO2 (51.38–55.16%) and Fe2O3 (5.31–7.97%), low content of Al2O3 (14.58–20.87%), and the other oxides with low content. The analysis result using the ICP-OES method indicated that bentonites in Tam Bo consisted of trace elements such as As, Ba, Cr, Cd, Co, Cu, La, La, Pb, Sb, Sc, V, Zn, and their content is similar to the values in peloid for the commercial use. Tam Bo bentonite has a pH value of 8.17, a very high CEC index (71 mg/100g), a plasticity index of 28%, expandability of 70%. All of the samples did not contain pathogenic bacteria. The study result confirms that Tam Bo bentonite responses to the criteria for making the peloid and similar to the peloids of Vale das Furnas (in Portugal), Calda (in Italy), Archena (in Spain).","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48934281","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 : 2020-09-14DOI: 10.15625/0866-7187/42/4/15410
N. Liem, Dang Văn Bao, D. K. Bac, Ngo Chi Cuong, P. Nga, Benjamin Burkhard, Giap Thi Kim Chi
The most important function of the coastal setback is to minimize damage due to coastal erosion, climate change response, and sea-level rise. There are many directions and methods of researching and assessing coastal changes and coastal erosion. This study presents the results of the shoreline changes in the area from Son Tra (Da Nang City) to Cua Dai (Hoi An City), Central Vietnam based on remote sensing data from 1965 to 2019. Three methods are used to include End Point Ratio (EPR), Linear Regression Rate (LRR), and Weighted Linear Regression (WLR). The results show that the EPR method is effective when calculating the rate of shoreline changes only at two different times. For more objective and reliable calculation, it is necessary to assess the shoreline changes over time. Meanwhile, the LRR method was shown to be superior because all shoreline data were taken into account during the construction of the regression line. However, when there is much shoreline data with different reliability, the WLR method proved more superior because of limited objective errors. The results show that from 1965 to 2019, the coast of the Son Tra - Cua Dai area had quite complicated fluctuations, of which the northern area (Son Tra) tended to accretion, the central area tends to be alternate between accretion and erosion, while the south area (Cua Dai) is strong to very strong erosion. The coast with sudden changes is the Cua Dai area with the shoreline change envelope (SCE) reaching 512m. The results also allow us to divide the coast of the Son Tra - Cua Dai area into 30 segments. They are clustered into 8 groups with different levels of erosion and accretion. This is an important basis for the setback zone establishment in the study area.
沿海退缩最重要的功能是将海岸侵蚀、气候变化响应和海平面上升造成的破坏降到最低。海岸变化与海岸侵蚀的研究和评价有许多方向和方法。基于1965 - 2019年越南中部Son Tra(岘港市)至Cua Dai(会安市)地区的遥感数据，研究了该地区海岸线变化的结果。采用终点比(End Point Ratio, EPR)、线性回归率(Linear Regression Rate, LRR)和加权线性回归(Weighted Linear Regression, WLR)三种方法。结果表明，EPR方法仅在两个不同时间计算海岸线变化率时是有效的。为了更客观可靠的计算，有必要对海岸线随时间的变化进行评估。同时，由于LRR方法在回归线的构建过程中考虑了所有的岸线数据，因此显示了LRR方法的优越性。然而，当岸线数据较多且信度不同时，由于客观误差有限，WLR方法更加优越。结果表明:1965 - 2019年，孙特拉—瓜岱地区海岸起伏较为复杂，其中北部(孙特拉)地区倾向于吸积，中部地区倾向于吸积与侵蚀交替，南部(瓜岱)地区则为强至强侵蚀。突变海岸为瓜岱地区，岸线变化包络线(SCE)达512m。研究结果还使我们能够将松特拉-瓜岱地区的海岸划分为30个段。它们被分成8组，具有不同程度的侵蚀和增生。这是建立研究区退退带的重要依据。
{"title":"Assessment of shoreline changes for setback zone establishment from Son Tra (Da Nang city) to Cua Dai (Hoi An city), Vietnam","authors":"N. Liem, Dang Văn Bao, D. K. Bac, Ngo Chi Cuong, P. Nga, Benjamin Burkhard, Giap Thi Kim Chi","doi":"10.15625/0866-7187/42/4/15410","DOIUrl":"https://doi.org/10.15625/0866-7187/42/4/15410","url":null,"abstract":"The most important function of the coastal setback is to minimize damage due to coastal erosion, climate change response, and sea-level rise. There are many directions and methods of researching and assessing coastal changes and coastal erosion. This study presents the results of the shoreline changes in the area from Son Tra (Da Nang City) to Cua Dai (Hoi An City), Central Vietnam based on remote sensing data from 1965 to 2019. Three methods are used to include End Point Ratio (EPR), Linear Regression Rate (LRR), and Weighted Linear Regression (WLR). The results show that the EPR method is effective when calculating the rate of shoreline changes only at two different times. For more objective and reliable calculation, it is necessary to assess the shoreline changes over time. Meanwhile, the LRR method was shown to be superior because all shoreline data were taken into account during the construction of the regression line. However, when there is much shoreline data with different reliability, the WLR method proved more superior because of limited objective errors. The results show that from 1965 to 2019, the coast of the Son Tra - Cua Dai area had quite complicated fluctuations, of which the northern area (Son Tra) tended to accretion, the central area tends to be alternate between accretion and erosion, while the south area (Cua Dai) is strong to very strong erosion. The coast with sudden changes is the Cua Dai area with the shoreline change envelope (SCE) reaching 512m. The results also allow us to divide the coast of the Son Tra - Cua Dai area into 30 segments. They are clustered into 8 groups with different levels of erosion and accretion. This is an important basis for the setback zone establishment in the study area.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41627258","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 : 2020-09-14DOI: 10.15625/0866-7187/42/4/15492
R. Shakirov, A. V. Sorochinskaja, N. Syrbu, U. Tsunogai, Tran Thi Hoang Yen
Paper presents the results of complex gas-geochemical studies of bottom sediments of the East Siberian Sea along the meridional profile from Cape Billings to the Mendeleev Ridge. Abnormal concentrations of methane (up to 2.4% vol.) and hydrogen (up to 600 ppm) are controlled by neotectonic faults and are typical for the areas of gas hydrate formation. The carbon isotope composition indicates the predominance of the thermogenic component. When studying the chemical composition of sediments, the data helped to identify the permeability zones of neotectonic faults that have favorable conditions for the concentration of a number of elements: Mn, Cu, Ag. Such zones are characterized by the gas anomalies in sediments (methane, hydrogen, etc.). The accumulation of anomalous metal contents is facilitated by specific geological conditions that occur in zones of gas anomalies within tectonically active structures, where fine-grained sediments enriched with organic matter are present. The gas-geochemical fields formed in this pattern can be applied as indicators in forecasting of hydrocarbon accumulations, for mapping permeable fault zones, and for the environmental impact assessing of hydrocarbon anomalies. This approach could be especially effective in the basins with low seismic activity such as seas of East Siberian shelf and some of the marginal seas of Pacific Ocean, for instance, South China Sea (Bien Dong).
{"title":"Gas-geochemical studies of gas fields and increased metal concentrations in the East Siberian Sea","authors":"R. Shakirov, A. V. Sorochinskaja, N. Syrbu, U. Tsunogai, Tran Thi Hoang Yen","doi":"10.15625/0866-7187/42/4/15492","DOIUrl":"https://doi.org/10.15625/0866-7187/42/4/15492","url":null,"abstract":"Paper presents the results of complex gas-geochemical studies of bottom sediments of the East Siberian Sea along the meridional profile from Cape Billings to the Mendeleev Ridge. Abnormal concentrations of methane (up to 2.4% vol.) and hydrogen (up to 600 ppm) are controlled by neotectonic faults and are typical for the areas of gas hydrate formation. The carbon isotope composition indicates the predominance of the thermogenic component. When studying the chemical composition of sediments, the data helped to identify the permeability zones of neotectonic faults that have favorable conditions for the concentration of a number of elements: Mn, Cu, Ag. Such zones are characterized by the gas anomalies in sediments (methane, hydrogen, etc.). The accumulation of anomalous metal contents is facilitated by specific geological conditions that occur in zones of gas anomalies within tectonically active structures, where fine-grained sediments enriched with organic matter are present. The gas-geochemical fields formed in this pattern can be applied as indicators in forecasting of hydrocarbon accumulations, for mapping permeable fault zones, and for the environmental impact assessing of hydrocarbon anomalies. This approach could be especially effective in the basins with low seismic activity such as seas of East Siberian shelf and some of the marginal seas of Pacific Ocean, for instance, South China Sea (Bien Dong).","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":"42 1","pages":"395-410"},"PeriodicalIF":1.5,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47370148","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 : 2020-09-14DOI: 10.15625/0866-7187/42/4/15282
Le Huy Minh, Vu Tuan Hung, Jyr‐Ching Hu, N. Minh, Bor‐Shouh Huang, H. Chen, N. Thắng, Nguyễn Hà Thành, Le Truong Thanh, Nguyen Thi Mai, Pham Thi Thu Hong
The paper presents an estimation of the Earth’s crustal motion from the continuous GPS data at 6 stations (MTEV, MLAY, DBIV, TGIV, SMAV and SLAV) in the Northwestern and at PHUT (Hanoi) station using GAMIT/GLOBK software. The absolute displacements of the Earth’s crust at 7 stations in the IGS14 frame are respectively: 34.10±0.71 mm/yr (DBIV), 34.31±0.65 mm/yr (PHUT), 34.51±0.75 mm/yr (SMAV), 34.55±0.80 mm/yr (MLAY), 34.80±0.72 mm/yr (TGIV), 34.93±0.99 mm/yr (SLAV) and 35.59±0.73 mm/yr (MTEV), in the southeastward with the azimuth range 104-108o. The Son La fault is a right-lateral slip fault with a shear amplitude of ~1.5 mm/yr. The Lai Chau-Dien Bien fault is a left-lateral slip fault with a shear amplitude of ~1.9 mm/yr. Although the absolute velocities at the DBIV, SMAV, SLAV, TGIV and MLAY stations are evaluated with the error <1 mm/yr, the relative displacement on the Ma River fault is of ~0.5 mm/yr, and it seems that we still do not have a reliable assessment of the slip rate on the Ma River right-lateral slip fault.
{"title":"Contemporary movement of the Earth's crust in the Northwestern Vietnam by continuous GPS data","authors":"Le Huy Minh, Vu Tuan Hung, Jyr‐Ching Hu, N. Minh, Bor‐Shouh Huang, H. Chen, N. Thắng, Nguyễn Hà Thành, Le Truong Thanh, Nguyen Thi Mai, Pham Thi Thu Hong","doi":"10.15625/0866-7187/42/4/15282","DOIUrl":"https://doi.org/10.15625/0866-7187/42/4/15282","url":null,"abstract":"The paper presents an estimation of the Earth’s crustal motion from the continuous GPS data at 6 stations (MTEV, MLAY, DBIV, TGIV, SMAV and SLAV) in the Northwestern and at PHUT (Hanoi) station using GAMIT/GLOBK software. The absolute displacements of the Earth’s crust at 7 stations in the IGS14 frame are respectively: 34.10±0.71 mm/yr (DBIV), 34.31±0.65 mm/yr (PHUT), 34.51±0.75 mm/yr (SMAV), 34.55±0.80 mm/yr (MLAY), 34.80±0.72 mm/yr (TGIV), 34.93±0.99 mm/yr (SLAV) and 35.59±0.73 mm/yr (MTEV), in the southeastward with the azimuth range 104-108o. The Son La fault is a right-lateral slip fault with a shear amplitude of ~1.5 mm/yr. The Lai Chau-Dien Bien fault is a left-lateral slip fault with a shear amplitude of ~1.9 mm/yr. Although the absolute velocities at the DBIV, SMAV, SLAV, TGIV and MLAY stations are evaluated with the error <1 mm/yr, the relative displacement on the Ma River fault is of ~0.5 mm/yr, and it seems that we still do not have a reliable assessment of the slip rate on the Ma River right-lateral slip fault.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49165017","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 : 2020-09-14DOI: 10.15625/0866-7187/42/4/15287
Nguyen Mai Lan
Polycyclic Aromatic Hydrocarbons (PAHs) in aircraft soot are capable to distribute in the gas phase and particulate phase in chemical transformations in the atmosphere. The desorption of PAHs from the soot surface is a preliminary step in the study of the reactivity of particulate PAHs. The desorption kinetics of PAHs are measured from soot samples to determine desorption rate constants for different PAHs as a function of temperature and the binding energies between PAHs and soot. The kinetics of degradation of particulate PAHs were studied in the flow reactor. The soot samples previously deposited on a Pyrex tube are introduced into the reactor along its axis and the concentrations of PAHs adsorbed on soot are determined by the High-Performance Liquid Chromatography (HPLC) as a function of the desorption time. The results show a correlation between the size of PAHs and the thermodynamics of desorption: with the PAHs have the same number of carbon atoms, their energies of desorption are very similar and increase with this number. The activation energies EA and the number of carbon atoms in PAHs have a linear correlation. It is consistent with the additivity of the laws Van der Waals. The similarity between the activation energies of desorption of PAHs and the corresponding sublimation enthalpies is consistent with the similarity between the graphitic structure of soot and the structure of PAHs.
{"title":"Desorption and re-adsorption of PAHS on aircraft soot surface","authors":"Nguyen Mai Lan","doi":"10.15625/0866-7187/42/4/15287","DOIUrl":"https://doi.org/10.15625/0866-7187/42/4/15287","url":null,"abstract":"Polycyclic Aromatic Hydrocarbons (PAHs) in aircraft soot are capable to distribute in the gas phase and particulate phase in chemical transformations in the atmosphere. The desorption of PAHs from the soot surface is a preliminary step in the study of the reactivity of particulate PAHs. The desorption kinetics of PAHs are measured from soot samples to determine desorption rate constants for different PAHs as a function of temperature and the binding energies between PAHs and soot. The kinetics of degradation of particulate PAHs were studied in the flow reactor. The soot samples previously deposited on a Pyrex tube are introduced into the reactor along its axis and the concentrations of PAHs adsorbed on soot are determined by the High-Performance Liquid Chromatography (HPLC) as a function of the desorption time. The results show a correlation between the size of PAHs and the thermodynamics of desorption: with the PAHs have the same number of carbon atoms, their energies of desorption are very similar and increase with this number. The activation energies EA and the number of carbon atoms in PAHs have a linear correlation. It is consistent with the additivity of the laws Van der Waals. The similarity between the activation energies of desorption of PAHs and the corresponding sublimation enthalpies is consistent with the similarity between the graphitic structure of soot and the structure of PAHs.","PeriodicalId":23639,"journal":{"name":"VIETNAM JOURNAL OF EARTH SCIENCES","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46032927","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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