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Understanding and improving Yangtze River Basin summer precipitation prediction using an optimal multi-Physics ensemble Front. Earth Sci. (IF 2.0) Pub Date : 2024-03-23 Yang Zhao, Fengxue Qiao, Xin-Zhong Liang, Jinhua Yu
This study employs the regional Climate-Weather Research and Forecasting model (CWRF) to first investigate the primary physical mechanisms causing biases in simulating summer precipitation over the Yangtze River Basin (YRB), and then enhance its predictive ability through an optimal multi-physics ensemble approach. The CWRF 30-km simulations in China are compared among 28 combinations of varying physics
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Geochemical characteristics, generation, and evolution mechanism of coalbed methane in the south-western Ordos Basin, China Front. Earth Sci. (IF 2.0) Pub Date : 2024-03-08 Yabing Lin, Yong Qin, Dongmin Ma, Shengquan Wang
The south-western Ordos Basin is rich in low-middle rank coalbed methane (CBM) resources; while the geochemical characteristics and genetic mechanism of CBM are not clear. Herein, according to geological and geochemical test data from gas and coal seam water from CBM wells in Bingchang, Jiaoxun, Huangling, Yonglong, and Longdong minging areas, we systematically studied the geochemical characteristics
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Changes of tropical cyclone size in three oceanic basins of the northern hemisphere from 2001 to 2021 Front. Earth Sci. (IF 2.0) Pub Date : 2024-02-29 Banglin Zhang, Jeremy Cheuk-Hin Leung, Shengyuan Liu, Jianjun Xu
In this study the changes of tropical cyclone (TC) size from 2001 to 2021 are analyzed based on linear and quadratic curve fittings of the National Hurricane Center (NHC) / Joint Typhoon Warning Center (JTWC) best track data, based on the radius of maximum wind (RMW) and the average radius of 34-kt wind (AR34), in three oceanic basins of the North Atlantic (NATL), the Western North Pacific (WPAC) and
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Low-latitude hydroclimate changes related to paleomagnetic variations during the Holocene in coastal southern China Front. Earth Sci. (IF 2.0) Pub Date : 2024-02-29 Tingwei Zhang, Xiaoqiang Yang, Jian Yin, Qiong Chen, Jianfang Hu, Lu Wang, Mengshan Ju, Qiangqiang Wang
The variations in precipitation have displayed a complex pattern in different regions since the mid-to-late-Holocene. Cloud formation processes may have a significant impact on precipitation, especially during the tropical marine processes and summer monsoon which convey abundant water vapor to coastal southern China and inland areas. Here, we use two 7500 year sedimentary records from the Pearl River
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Quantitative evaluation of adsorbed and free water in deep shales: a case study on the Wufeng-Longmaxi Formations from the Luzhou area, southern Sichuan Basin, China Front. Earth Sci. (IF 2.0) Pub Date : 2024-02-26 Shengxian Zhao, Yongyang Liu, Shuangfang Lu, Shuaihu Liu, Wenbiao Li, Zhiyan Zhou, Yashuo Wang, Zhaojing Song
Deep shale gas reservoirs commonly contain connate water, which affects the enrichment and migration of shale gas and has attracted the attention of many scholars. It is significant to quantitatively estimate the amounts of adsorbed and free water in shale matrix pores, considering the different impacts of pore water (adsorbed water and free water) on shale gas. In this paper, pore water in six deep
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Dynamic synthetic analysis of circulation field of tropical cyclones affecting Shanghai Front. Earth Sci. (IF 2.0) Pub Date : 2024-02-08 Wen Gu, Caijun Yue, Zhihui Han, Yanqing Gao, Yuqi Tang, Xiangyu Ao, Yao Yao
Eleven tropical cyclones (TCs) affected Shanghai and crossed the same latitude as Shanghai from 2007 to 2018. According to similar tracks from best-track data, TCs that cause significant precipitation in Shanghai can be divided into three types: landfall TCs, nearshore northward TCs, and western TCs. Based on ERA5 reanalysis data, the dynamic synthesis method was used to synthesize TC circulation situations
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Changes in lake area and water level in response to hydroclimate variations in the source area of the Yellow River: a case study from Lake Ngoring Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-23 Yang Pu, Min Zhan, Xiaohua Shao, Josef P. Werne, Philip A. Meyers, Jiaojiao Yao, Da Zhi
In the north-eastern Qinghai-Tibet Plateau (QTP), the source area of the Yellow River (SAYR) has been experiencing significant changes in climatic and environmental conditions in recent decades. To date, few studies have combined modern hydrological conditions with paleoclimate records to explore the mechanism(s) of these changes. This study seeks to improve understanding of hydrological variability
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Climate change in the Hongliujing area of Lop Nur over the past 200 years revealed by the stable oxygen isotopes of Tamarix cones Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-13 Zhiguang Li, Yaqing Dong, Haoyu Zhang, Hongxiao Sun, Danyang Jia, Shikai Song, Yuanjie Zhao
The layers of Tamarix cones within sedimentary deposits in arid regions have significant chronological and paleoenvironmental implications. Here, we compare the δ18O values of Tamarix cones in the Hongliujing area of Lop Nur with meteorological data for the Ruoqiang meteorological station for 1960–2019 AD. Linear regression analysis was used to reconstruct the average temperature for April and the
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Tree ring derived summer temperature variability over the past millennium in the western Himalayas of northern Pakistan Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-13 Fayaz Asad, Haifeng Zhu, Tabassum Yaseen, Ru Huang, Mukund Palat Rao
Long-term high resolution climate proxies are essential for understanding climate variability particularly, in regions such as the western Himalayas of northern Pakistan, where few long-term climate records are available. Using standard dendrochronological methods, an 1132-year (882 to 2013 C.E.) tree-ring chronology of Juniperus excelsa M. Bieb was established from the western Himalayas, northern
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Dust transport information and paleoclimatic changes revealed by the loess in Ranwu, south-eastern Xizang Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-13 Meihui Pan, Huimin Zhao, Anna Yang, Yougui Chen, Chenlu Li
The loess accumulation process has great potential to record patterns of atmospheric circulation change, paleoclimate, and paleoenvironmental evolution. South-eastern Xizang is a climatically sensitive region and here, we analyze a loess profile at Ranwu in order to explore the processes and interactions of dust transport and paleoclimate evolution in the region. Based on parametric grain size end-member
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Complementarity of lacustrine pollen and sedimentary DNA in representing vegetation on the central-eastern Tibetan Plateau Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-12 Fang Tian, Meijiao Chen, Weihan Jia, Ulrike Herzschuh, Xianyong Cao
Plant environmental DNA extracted from lacustrine sediments (sedimentary DNA, sedDNA) has been increasingly used to investigate past vegetation changes and human impacts at a high taxonomic resolution. However, the representation of vegetation communities surrounding the lake is still unclear. In this study, we compared plant sedDNA metabarcoding and pollen assemblages from 27 lake surface-sediment
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Late Holocene brGDGTs-based quantitative paleotemperature reconstruction from lacustrine sediments on the western Tibetan Plateau Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-12 Xiumei Li, Sutao Liu, Juzhi Hou, Zhe Sun, Mingda Wang, Xiaohuan Hou, Minghua Liu, Junhui Yan, Lifang Zhang
We present a quantitative mean annual air temperature (MAAT) record spanning the past 4700 years based on the analysis of branched glycerol dialkyl glycerol tetraethers (brGDGTs) from a sediment core from Xiada Co, an alpine lake on the western Tibetan Plateau (TP). The record indicates a relatively stable and warm MAAT until 2200 cal yr BP; subsequently, the MAAT decreased by ∼4.4°C at ∼2100 cal yr
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Lacustrine record of 800 yr hydrological variations on the central Tibetan Plateau Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-12 Hongliang Zhang, Hucai Zhang, Yanbin Lei
Zige Tangco is a meromictic saline lake located on the central Tibetan Plateau. Two parallel cores (ZGTC A-1 and ZGTC A-2) were collected from the lake at a water depth of 25 m during summer 2006. The chronology of core A-1 was reconstructed based on the Constant Initial Concentration (CIC) model of 210Pb and three accelerator mass spectrometry (AMS) ages from the chitin fragments. The hard water effect
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Vegetation stability during the last two centuries on the western Tibetan Plateau: a palynological evidence Front. Earth Sci. (IF 2.0) Pub Date : 2024-01-12 Yanrong Zhang, Nannan Wang, Lina Liu, Mingda Wang, Xiaoshan Yu, Xianyong Cao
Investigating the dynamics of vegetation is an essential basis to know how to protect ecological environments and to help predict any changes in trend. Because of its fragile alpine ecosystem, the Tibetan Plateau is a particularly suitable area for studying vegetation changes and their driving factors. In this study, we present a high-resolution pollen record covering the last two centuries extracted
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Deformation characteristics and analog modeling of transtensional structures in the Dongying Sag, Bohai Bay Basin Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-29 Dawei Dong, Li Zhao, Weizhong Zhang, Jiyan Li, Ruixiang Zhang, Jianlei Yang, Guangzeng Wang
Hydrocarbon exploration in the Dongying Sag is constrained by the development of many Cenozoic transtensional structures with complex patterns and dynamic mechanisms. This study uses seismic interpretation and analog modeling to investigate these transtensional structures. Significant results include dividing these transtensional structures into boundary fault, oblique rifting, and deep strike-slip
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The determination of sedimentary environment and associated energy in deep-buried marine carbonates: insights from natural gamma ray spectrometry log Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-28 Jingyan Liu, Qian Chang, Junlong Zhang, Hui Chai, Feng He, Yizan Yang, Shiqiang Xia
It has always been challenging to determine the ancient sedimentary environment and associated energy in deep-buried marine carbonates. The energy represents the hydrodynamic conditions that existed when the carbonates were deposited. The energy includes light and chemical energies in compounds and kinetic energy in currents and mass flow. Deep-buried marine carbonates deposited during the Ordovician
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Detecting the spatial-temporal pattern of moisture evolution on the Tibetan Plateau during the Holocene by model-proxy comparison Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-28 Zeyu Zheng, Liya Jin, Jinjian Li, Xiaojian Zhang, Jie Chen
The Tibetan Plateau (TP) is a key region for environmental and climatic research due to its significant linkages with large-scale atmospheric circulation. Understanding the long-term moisture evolution pattern and its forcing mechanisms on the TP during the Holocene may provide insights into the interaction between low-latitude climate systems and midlatitude westerlies. Here, we synthesized 27 paleoclimate
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Characteristics of microscopic pore heterogeneity and development model of Wufeng–Longmaxi Shales in the Pengshui area of south-east Chongqing Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-28 Lu Sun, Zhigang Wen, Guisong He, Peixian Zhang, Chenjun Wu, Liwen Zhang, Yingyang Xi, Bo Li
Normal-pressure shale gas reservoirs are widely distributed in south-eastern Chongqing and show good potential for resource exploration. This paper reports the organic matter (OM), physical, and pore characteristics, mineral composition, and gas content of representative shale samples from the Upper Ordovician Wufeng Formation and Member 1 of the Lower Silurian Longmaxi Formation (Long 1 Member). Microscopic
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The important role of Turbidity Maximum Zone in sedimentary dynamic of estuarine mangrove swamp Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-28 Tao Liu, Ying Liu, Baoqing Hu
Sedimentation is a key process affecting wetland sustainability and carbon burial flux. In context of sea level rise, climate change and human activities, further understanding about the sedimentary dynamic in wetland is critical in predicting the landscape evolution or the change in carbon burial flux. In this study, based on the field hydrological observation in a mangrove system in the Nanliu River
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Holocene temperature variation recorded by branched glycerol dialkyl glycerol tetraethers in a loess-paleosol sequence from the north-eastern Tibetan Plateau Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-28 Tianxiao Wang, Duo Wu, Tao Wang, Lin Chen, Shilong Guo, Youmo Li, Chenbin Zhang
Reconstructing Holocene temperature evolution is important for understanding present temperature variations and for predicting future climate change, in the context of global warming. The evolution of Holocene global temperature remains disputed, due to differences between proxy reconstructions and model simulations, a discrepancy known as the ‘Holocene temperature conundrum’. More reliable and quantitative
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Alternating influences of the Westerlies and Indian Summer Monsoon on the hydroclimate of the source region of the Yarlung Tsangpo over past 4000 yr Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-28 Zhe Sun, Zirui Huang, Kejia Ji, Mingda Wang, Juzhi Hou
The Yarlung Tsangpo, the longest river in the southern Tibetan Plateau (TP), has attracted much research attention aimed at understanding the factors controlling its modern hydrology and possible future discharge in the context of ongoing climate change. However, partly due to the complex regional climatic background, no consistent conclusions have been reached, especially for its upper reaches. Paleohydrological
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Spatial distribution of charcoal in topsoil and its potential determinants on the Tibetan Plateau Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-05 Yixuan Wang, Chaoqun Cao, Yanrong Zhang, Lina Liu, Nannan Wang, Wenjia Li, Xianyong Cao
As an important proxy for investigating past fire activities, charcoal is often used to explore the characteristics of fire distribution and its relationships with vegetation, climate, and human activities. Research into the spatial distribution and environmental determinants for charcoal, however, is still limited. In this study, we identified and counted charcoal from topsoil samples covering the
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A re-evaluation of the average chain length of lacustrine sedimentary n-alkanes as a paleoproxy on the Qinghai-Tibet Plateau Front. Earth Sci. (IF 2.0) Pub Date : 2023-12-05 Mingda Wang, Qin Li, Jaime Toney, David Henderson, Juzhi Hou
Long-chain n-alkanes are one of the most common organic compounds in terrestrial plants and they are well-preserved in various geological archives. nalkanes are relatively resistant to degradation and thus they can provide high-fidelity records of past vegetation and climate changes. Nevertheless, previous studies have shown that the interpretation of n-alkane proxies, such as the average chain length
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Relationship between the rise and fall of Loulan ancient city and centennial-scale climate events and cycles Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-22 Deke Xu, Chang Li, Yingyu Jin, Zhenhua Deng, Bing Xu, Kangkang Li, Jianping Zhang, Xiaohong Sun, Jing Feng, Yingxin Jiao, Hao Li, Xiaoguang Qin
The discovery of Loulan ancient city (LA) in the early 20th century has important significance for understanding the history of Western regions and the Silk Road civilization. The current academic community still has disputes on whether LA was the capital of Loulan Kingdom, the time of its rise, peak and decline, and the process, rate and driving mechanism of human activity change. This study uses
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CO2 geological sequestration potential of the low-rank coals in the southern margin of the Junggar Basin Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-20 Qun Zhao, Ze Deng, Meng Zhao, Dexun Liu
Carbon capture, utilization, and storage (CCUS) is considered one of the most effective measures to achieve net-zero carbon emissions by 2050, and low-rank coal reservoirs are commonly recognized as potential CO2 storage sites for carbon sequestration. To evaluate the geological CO2 sequestration potential of the low-rank coal reservoirs in the southern margin of the Junggar Basin, multiple experiments
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Effect of permeability and its horizontal anisotropy on enhanced coalbed methane recovery with CO2 storage: quantitative evaluation based on staged CH4 output inhibition Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-22 Ziliang Wang, Shuxun Sang, Xiaozhi Zhou, Xudong Liu, Shouren Zhang
The permeability and its horizontal anisotropy induce a critical influence on staged CH4 output inhibition process. However, a quantitative evaluation of this influence has been rarely reported in the literature. In this work, the impact of horizontal anisotropic permeability on CO2-ECBM was numerically investigated. The variation in the staged CH4 output inhibition was analyzed. The ideal displacement
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Laboratory simulation of CO2 immiscible gas flooding and characterization of seepage resistance Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-18 Jie Chi, Binshan Ju, Wenbin Chen, Mengfei Zhang, Rui Zhang, Anqi Miao, Dayan Wang, Fengyun Cui
CO2 flooding can significantly improve the recovery rate, effectively recover crude oil, and has the advantages of energy saving and emission reduction. At present, most domestic researches on CO2 flooding seepage experiments are field tests in actual reservoirs or simulations with reservoir numerical simulators. Although targeted, the promotion is poor. For the characterization of seepage resistance
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Methane adsorption effected by pore structure of overmature continental shale: Lower Cretaceous Shahezi Formation, Xujiaweizi Fault, Songliao Basin Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-18 Pengfei Zhang, Shuangfang Lu, Nengwu Zhou, Zizhi Lin, Xiangchun Chang, Junjian Zhang, Guo Chen, Yumao Pang, Junjie Wang, Hongsheng Huang, Qi Zhi
Overmature continental shale is commonly developed, but few studies have given insight into its pore structure and sorption capacity. Various techniques, including SEM, helium porosity and permeability, N2/CO2 adsorption, MICP, and NMR, were used to detect the pore structure of shale from the Shahezi Formation, Xujiaweizi Fault, Songliao Basin. The excess methane adsorption volumes were measured by
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A novel numerical simulation of CO2 immiscible flooding coupled with viscosity and starting pressure gradient modeling in ultra-low permeability reservoir Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-18 Jie Chi, Binshan Ju, Jiabei Wang, Xing Zhang, Wenbin Chen, Mengfei Zhang
CO2 immiscible flooding is an environmentally-friendly and effective method to enhance oil recovery in ultra-low permeability reservoirs. A mathematical model of CO2 immiscible flooding was developed, considering the variation in crude oil viscosity and starting pressure gradient in ultra-low permeability reservoirs based on the non-Darcy percolation theory. The mathematical model and numerical simulator
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Constraints of palaeoenvironment on organic matter of Benxi Formation shale and discussion on enrichment mechanism under different facies Front. Earth Sci. (IF 2.0) Pub Date : 2023-11-13 Qianyang He, Delu Li, Qiang Sun, Jianwen Gao, Haibin Li, Xinhu Li, Xiaochen Zhao, Shaofei Wang, Gaozhe Ji
As a hydrocarbon-rich sedimentary basin in China, the Ordos Basin has enormous potential for shale gas resources. The shale of the Upper Carboniferous Benxi Formation is rich in organic matter, however, its palaeoenvironment and organic matter enrichment mode are yet to be revealed. In this study, the geochemical characteristics of the shale of the Benxi Formation in the east-central part of the Ordos
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Combined effects of massive reclamation and dredging on the variations in hydrodynamic and sediment transport in Lingdingyang Estuary, China Front. Earth Sci. (IF 2.0) Pub Date : 2023-10-11 Kanglin Chen, Yitong Lin, Jing Liu, Zixiao He, Liangwen Jia
Anthropogenic disturbances associated with the rapid development of coastal cities have drastically influenced the hydrodynamics and sediment transport processes in many large estuaries globally. Lingdingyang Estuary (LE), located in the central and southern part of the Pearl River Delta, southern China with a long history of high-intensity anthropogenic disturbances, was studied to explore the contribution
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Global precipitation change during the Holocene: a combination of records and simulations Front. Earth Sci. (IF 2.0) Pub Date : 2023-09-13 Wangting Ye, Yu Li
Precipitation can shape our climate both in the present and the future. Even though we have made significant advances in studying the mechanisms of millennial-scale climate changes through high-resolution records, we still cannot quantitatively characterize the global spatiotemporal precipitation variations within the Holocene. Therefore, we developed a new approach to integrating data from 349 globally
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Coal and rock dynamic disaster prevention and control technology in the large mining face of a deep outburst mine Front. Earth Sci. (IF 2.0) Pub Date : 2023-09-08 Jianguo Zhang, Man Wang, Hongwei Zhou, Dongming Zhang, Beichen Yu, Chongyang Wang, Yujie Wang
In this study, we systematically studied the occurrence regularity of in situ stress in the Pingdingshan mine. The critical criterion model of coal-rock destabilization was established based on the theoretical framework of fracture mechanics. Furthermore, we analyzed the coupling destabilization mechanism of in situ stress and gas and studied the influence of the variation between original rock stress
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A method for predicting the probability of formation of complex hydraulic fracture networks in shale reservoirs: development and application Front. Earth Sci. (IF 2.0) Pub Date : 2023-09-01 Xiaona Zhang, Yanbin Yao, Yongshang Kang
Shales can form a complex fracture network during hydraulic fracturing, which greatly increases the stimulated reservoir volume (SRV) and thus significantly increases oil or gas production. It is therefore important to accurately predict the probability of formation of the hydraulic fracture network for shale gas exploration and exploitation. Conventional discriminant criteria are presented as the
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Evaluation of infill well pattern based on the dynamic change of reservoirs during coalbed methane development Front. Earth Sci. (IF 2.0) Pub Date : 2023-09-01 Qian Zhang, Shuheng Tang, Songhang Zhang, Xinlu Yan, Kaifeng Wang, Tengfei Jia, Zhizhen Wang
With the deepening of coalbed methane (CBM) exploration and development, the problem of low gas production has gradually become one of the main factors restricting the development of the CBM industry in China. Reasonable well pattern deployment can improve the productivity of CBM wells and reduce the cost of production, while the reservoir changes of CBM wells play a important role for well pattern
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Large eddy simulation of flow over a three-dimensional hill with different slope angles Front. Earth Sci. (IF 2.0) Pub Date : 2023-08-10 Liang Li, Deqian Zheng, Guixiang Chen, Pingzhi Fang, Wenyong Ma, Shengming Tang
Slope variation will significantly affect the characteristics of the wind field around a hill. This paper conducts a large-eddy simulation (LES) on an ideal 3D hill to study the impact of slope on wind field properties. Eight slopes ranging from 10° to 45° at 5° intervals are considered, which covers most conventional hill slopes. The inflow turbulence for the LES is generated by adopting a modified
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Assessing the cost reduction potential of CCUS cluster projects of coal-fired plants in Guangdong Province in China Front. Earth Sci. (IF 2.0) Pub Date : 2023-08-03 Muxin Liu, Yueze Zhang, Hailin Lan, Feifei Huang, Xi Liang, Changyou Xia
Carbon capture, utilization, and storage (CCUS) have garnered extensive attention as a target of carbon neutrality in China. The development trend of international CCUS projects indicates that the cluster construction of CCUS projects is the main direction of future development. The cost reduction potential of CCUS cluster projects has become a significant issue for CCUS stakeholders. To assess the
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Research on the pressure variation law and enhancing CBM extraction application effect of CO2 phase transition jet coal seam fracturing technology Front. Earth Sci. (IF 2.0) Pub Date : 2023-08-03 Xin Bai, Zhuoli Zhou, Guicheng He, Dongming Zhang, Han Yang, Zenrui Fan, Dengke Wang
Due to the limited permeability and high methane content of the majority of China’s coal seams, significant coal mining gas disasters frequently occur. There is an urgent need to artificially improve the permeability of coalbed methane (CBM) reservoirs, enhance the recovery efficiency of CBM and prevent mine gas accidents. As a novel coal rock fracture technology, the CO2 phase transition jet (CPTJ)
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Study on in situ stress testing method based on Kaiser effect of acoustic emission and COMSOL simulation Front. Earth Sci. (IF 2.0) Pub Date : 2023-08-03 Chenyu Wang, Dongming Zhang, Shujian Li, Yu Chen, Chongyang Wang, Kangde Ren
In situ stress testing can improve the safety and efficiency of coal mining. Identifying the Kaiser effect point is vital for in situ stress calculations; however, the in situ stress calculation is limited by the rock sampling angle. Here, the Kaiser effect point identification theory is established and applied to the Xuyong Coal Mine. Uniaxial compression and acoustic emission experiments were carried
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Comparative experimental study on porosity, mechanical and CO2 adsorption characteristics of coal and shale Front. Earth Sci. (IF 2.0) Pub Date : 2023-08-03 Haitao Li, Guo Yu, Xiaolei Wang, Dongming Zhang
To compare the pore structure, mechanical and CO2 adsorption properties of coal and shale, a series of experiments were carried out using nuclear magnetic resonance (NMR), uniaxial compression, Brazilian splitting, and high-pressure CO2 adsorption. The results show that the total porosity of coal is 7.51 times that of shale, and shale is dominated by adsorption pores, while adsorption pores and seepage
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Deformation mechanism and hydrocarbon significance of Eocene organic-rich fine-grained soft sediments in the Leijia Region, Liaohe Depression Front. Earth Sci. (IF 2.0) Pub Date : 2023-08-03 Yijie Wen, Jianguo Zhang, Shu Tao, Chenyu Cai
The deformation structure of soft sediments has always been a research hotspot, which is of great significance for analyzing the tectonic and sedimentary evolution background of a basin, as well as the physical properties of reservoirs. Previous studies have reported that a large number of soft sediment deformation structures are developed in the western part of Liaohe depression. In this study, through
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Geochronology, petrogenesis, and geological significance of the quartz vein-type copper deposits in Longwei area, north-west Dayaoshan, Guangxi Front. Earth Sci. (IF 2.0) Pub Date : 2023-07-28 Song Fu, Shehong Li, Changxing Lv, Longqing Shi, Xuhan Hu, Jinming Wu, Zhuolin Xie
Quartz-vein-type copper deposits were discovered in SN-trend ore-bearing structures in north-west Dayaoshan, Guangxi. Lack of reports on the precise metallogenic age of these deposit has become a bottleneck in metallogenic research in this area. In this study, the quartz vein-type copper mine in Longwei area of Jinxiu was selected as the research object. Fresh illite samples in the fault gouges and
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Quantitative attribution of Northern Hemisphere temperatures over the past 2000 years Front. Earth Sci. (IF 2.0) Pub Date : 2023-07-22 Feng Shi, Mingfang Ting, Zhengtang Guo
Quantitative assessment of natural internal variability and externally forced responses of Northern Hemisphere (NH) temperatures is necessary for understanding and attributing climate change signals during past warm and cold periods. However, it remains a challenge to distinguish the robust internally generated variability from the observed variability. Here, large-ensemble (70 member) simulations
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Assessing the quality of chlorophyll-a concentration products under multiple spatial and temporal scales Front. Earth Sci. (IF 2.0) Pub Date : 2023-07-12 Zheng Wang, Qun Zeng, Shike Qiu, Chao Wang, Tingting Sun, Jun Du
The chlorophyll-a concentration data obtained through remote sensing are important for a wide range of scientific concerns. However, cloud cover and limitations of inversion algorithms of chlorophyll-a concentration lead to data loss, which critically limits studying the mechanism of spatial-temporal patterns of chlorophyll-a concentration in response to marine environment changes. If the commonly
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Effect of damage zone around borehole on carbon dioxide injection promoted gas extraction in soft and low-permeability coal seam Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-30 Lijun Zhou, Xihua Zhou, Gang Bai, Xianlin Li, Mingkun Luo
Injecting external CO2 into soft and low-permeability coal seams can improve CH4 extacctinn efficiency, and also benefit in CO2 sequestration. However, the distribution law of damage zone around borehole in soft coal seam and its effect on the efficiency of CO2 injection promoted CH4 extraction are not clear. In this paper, a multi-physics coupling mathematical model considering damage effect is established
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Reasonable start time of carbon dioxide injection in enhanced coalbed methane recovery involving thermal-hydraulic-mechanical couplings Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-16 Chaojun Fan, Lei Yang, Bin Xiao, Lijun Zhou, Haiou Wen, Hao Sun
Injection of gas (CO2) into coal seams is an effective method to benefit from both CO2 geological storage and coalbed methane recovery. Based on the dual pore structure of coal mass, and the Weibull distribution of fracture permeability, a menmal-hydraulic-mechanical (THM) coupling mathematical model is proposed involving the non-isothermal adsorption of binary gases, dynamic gas diffusion between
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Geological modeling of coalbed methane reservoirs in the tectonically deformed coal seam group in the Dahebian block, western Guizhou, China Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-15 Yong Shu, Shuxun Sang, Xiaozhi Zhou
The widely spread Carboniferous-Permian coal seam group in southern China has great potential for coalbed methane resources, but the extensively developed tectonically deformed coal seriously restricts its development. Taking the Dahebian block in western Guizhou as the study area, the geological model of coalbed methane reservoirs in the tectonically deformed coal seam group was established, and the
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Study on fracture characteristics in coal and shale for coal-measure gas reservoir based on 3D CT reconstruction and fractal features Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-13 Huijun Wang, Shangbin Chen, Shaojie Zhang, Chengxing Zhang, Yang Wang, Gaofeng Yi, Yixuan Peng
Pores and fractures are important components of flow channels in coal-measure gas reservoirs. While considerable studies have been conducted on pore structure evolution, very few studies have investigated the fracture distribution and self-similarity characteristics. To reveal the characteristics of fracture distribution in coal and shale reservoirs, computed tomography studies were performed on 15
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Long-term evolution of winter habitats in Poyang Lake derived from satellite imagery using machine learning methods Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-13 Siqin Qi, Jiayi Pan, Adam T. Devlin
Poyang Lake is a freshwater lake in China which is a vital winter habitat for many kinds of wildlife and a critical component of the regional ecology. Here, we use Landsat satellite imagery to systematically assess habitat characteristic changes from 1990 to 2021. Four machine learning methods including random forest (RF), gradient boosting tree (GBT), support vector machine (SVM) and classification
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Effects of sub-/super-critical CO2 on the fracture-related mechanical characteristics of bituminous coal Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-13 Zedong Sun, Hongqiang Xie, Gan Feng, Xuanmin Song, Mingbo Chi, Tao Meng, Bole Sun
Injecting carbon dioxide CO2 into a coal seam is an important way to improve coalbed methane recovery and to store geological carbon. The fracture mechanical characteristics of bituminous coal determine the propagation and evolution of cracks, which directly affect CO2 storage in coal seams and the efficiency of resource recovery. This study applied CO2 adsorption and three-point bending fracture experiments
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Morphological characteristics and evolution model of slope units along loess gully cross section Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-13 Lulu Liu, Fayuan Li, Xue Yang, Jianhua Cheng
Gully morphology is an important part of loess landform research. Along with gully development, the variation of its cross section is the most significant, and it can intuitively reflect the characteristics of the lateral widening of the gully slope. Therefore, in-depth research of the variation of the cross-sectional morphology of the gully is helpful to understanding the development process of the
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Fine classification of rice paddy using multitemporal compact polarimetric SAR C band data based on machine learning methods Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-14 Xianyu Guo, Junjun Yin, Kun Li, Jian Yang, Huimin Zou, Fukun Yang
Rice is an important food crop for human beings. Accurately distinguishing different varieties and sowing methods of rice on a large scale can provide more accurate information for rice growth monitoring, yield estimation, and phenological monitoring, which has significance for the development of modern agriculture. Compact polarimetric (CP) synthetic aperture radar (SAR) provides multichannel information
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Amplitude variation with offset and azimuth inversion to predict and evaluate coal seam fracture parameters Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-09 Haibo Wu, Shujie Zhu, Qinjie Liu, Shouhua Dong, Yanhui Huang, Pingsong Zhang
Amplitude variation with offset and azimuth (AVOA) inversion is a mainstream method for predicting and evaluating fracture parameters of conventional oil and gas reservoirs. However, its application to coal seams is limited because of the specificity of the equivalent media model for coal—also, the traditional seismic acquisition system employed in coal fields falls within a narrow azimuth. In this
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Measurement of CO2 adsorption capacity with respect to different pressure and temperature in sub-bituminous: implication for CO2 geological sequestration Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-09 Sijian Zheng, Shuxun Sang, Shiqi Liu, Meng Wang, Lutong Cao, Xin Jin, Guangjun Feng, Yi Yang
CCUS (carbon capture, utilization, and storage) technology is regarded as a bottom method to achieve carbon neutrality globally. CO2 storage in deep coal reservoirs serves as a feasible selection for CCUS, and its storage potential can be attributed to the CO2 adsorption capacity of the coal. In this paper, a series of CO2 adsorption isotherm experiments were performed at different pressures and temperatures
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Characteristics and evolution of faults in the north-central Yin’e Basin and the effects on the coal-seam in the Cretaceous strata Front. Earth Sci. (IF 2.0) Pub Date : 2023-06-05 Qiang Yu, Baojiang Wang, Zhanli Ren, Xianyao Sun, Xianghe Lei, Ahmed Khaled, Qike Yang
Research on the characteristics of faults and their evolutionary history since the Cretaceous in the Suhongtu-Dagu depressions can provide a theoretical basis for geological evaluation of the coal seams in the Suhongtu Formation in the northern-central region of the Yin’e Basin. Using 3-D seismic-logging inversion techniques, seismic stratigraphic calibration, stratigraphic sequence delineation, and
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Pore structure evolution of mudstone caprock under cyclic load-unload and its influence on breakthrough pressure Front. Earth Sci. (IF 2.0) Pub Date : 2023-05-27 Junchang Sun, Zhiqiang Dong, Sinan Zhu, Shifeng Tian, Junping Zhou
The pore structure of caprock plays an important role in underground gas storage security, as it significantly influences the sealing capacity of caprock. However, the pore structure evolution of caprock with the cyclic stress perturbations triggered by the cyclic gas injection or extraction remains unclear. In this study, the pore structure changes of mudstone caprock under cyclic loading and unloading
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Geochemical characteristics of produced fluids from CBM wells and their indicative significance for gas accumulation in Daning-Jixian block, Ordos Basin Front. Earth Sci. (IF 2.0) Pub Date : 2023-05-25 Taotao Yan, Chao Yang, Shuai Zheng, Yadong Bai, Wei Chen, Yanfei Liu, Wenguang Tian, Shasha Sun, Shangwen Jin, Jiahang Wang, Zhenxing Liu, Huifang Yao
The Daning-Jixian block, the eastern edge of the Ordos Basin, is one of the most potential areas for CO2 geological storage, enhanced coalbed methane recovery (ECBM) exploration and production in China in recent decades. The ionic composition and total dissolved solids (TDS) of the produced water, coal organic matter maturity, molecular composition and carbon isotope characteristics of the produced
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Research on carbon emissions embodied in China-Russia trade under the background of the Belt and Road Front. Earth Sci. (IF 2.0) Pub Date : 2023-05-22 Yang Yu, Yiming Du, Wei Xu, Qi Liu
Based on the latest China-Russia input-output data sets over the period from 2007 to 2015, this study quantified the flow of embodied carbon emissions in China-Russia trade using the emission embodied in bilateral trade (EEBT) approach. In addition, the structural decomposition analysis (SDA) was employed to identify the potential driving factors that affect embodied carbon in imports and exports.
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Gas-in-place and its influence factors of the upper Paleozoic coal-bearing shale in the Qinshui Basin, China Front. Earth Sci. (IF 2.0) Pub Date : 2023-05-22 Chengang Lu, Ping Gao, Gang Li, Yue Feng, Xiaorong Qu, Yufei Su, Xianming Xiao
Coal-bearing shale shows great potential for unconventional gas resources in China, while its exploration and development have been challenging for a long time. Gas-in-place (GIP) is critical to shale gas evaluation, but the major factors controlling the GIP content of coal-bearing shale remain unclear. To address this issue, the coal-bearing shales of the upper Carboniferous-lower Permian Taiyuan
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Water-bearing characteristics and their effects on the nanopores of overmature coal-measure shales in the Wuxiang area of the Qinshui Basin, north China Front. Earth Sci. (IF 2.0) Pub Date : 2023-05-22 Peng Cheng, Xianming Xiao, Hui Tian, Jian Sun, Qizhang Fan, Haifeng Gai, Tengfei Li
In this study, a group of overmature coal-measure shale core samples was collected in situ from an exploration well located in the Wuxiang area of the Qinshui Basin, north China. The pore water contents (CPW) of the shales under as-received conditions, equilibrium water contents (CEW) of the shales under moisture equilibrium conditions (relative humidity: 100%), and nanopore structures of the shales