Earth Sciences Commons^™

Elastic Wave Prestack Reverse Time Migration On Undulating Surfac, Liu Yang, Zhao Hu, Yin Cheng, Wu Sihai, Dai Ronghuo, Di Zhixin

Coal Geology & Exploration

At present, seismic exploration is facing many challenges in the "double complex" area, especially the undulating surface make it difficult to accurately image the underground complex structures. In this paper, we have studied the elastic wave prestack reverse time migration method for undulating surface, and a simple and effective treatment method was adopted to solve the free boundary conditions of undulating surface. In addition, the storage strategy of the effective boundary was used to solve the problem of big storage of elastic wave prestack reverse time migration. The numerical experimental results also show that this method can accurately reconstruct the …

Influence Mechanism Of Hard Brittle Abrasive On The Drilling Performance Of Impregnated Diamond Bit, Wang Jialiang, Wei Wenjie, Zhang Shaohe, Peng Fenfei

Coal Geology & Exploration

In order to improve the performance of diamond bit, impregnated diamond bit was prepared by adding different mass of hard brittle abrasive into matrix and drilling performance was tested by drilling experiments. The effect of hard brittle abrasive on drilling performance was studied. The results show that adding 5.5% SiC particle had better effect and the drilling efficiency increased by 55.14% compare with common bit. The hard brittle abrasive in the matrix can improving the microstructure of bit. The hard brittle abrasive left in the down hole can improve the erosion performance of washing fluid to matrix and increase the …

Finite Element 2d Forward Modeling Of Dc Method With Line Source, Xie Haijun, Li Zhiqiang, Li Sheng

Coal Geology & Exploration

In direct current prospecting, the forward calculation of 3D point source is complex and the calculation quantity is large, and using the Fourier transform can converted into 2D point source, but it is more complicated than that of 2D line source. This paper is based on Matlab programming, using the first boundary condition, and gives numerical solution of two-dimensional finite element of DC method with line source, through comparing with theoretical value of homogeneous half-space, the correctness of calculation results was verified. Then the high and low resistivity geoelectric models were built, the response of single side power supply and …

The Research Progress And Work Prospect Of Special Purpose Coal, Qiao Junwei, Ning Shuzheng, Qin Yunhu, Zhang Ning, Li Congcong, Zhang Jianqiang, Wei Yingchun, Zhu Shifei, Zhu Kaijia

Coal Geology & Exploration

Based on the refined geological exploration of coal, the clean and efficient use of coal, this paper reviews the implications of scarce coal and special purpose coal in previous studies. It was pointed out that special purpose coal is based on clean and efficient use of coal for coal resources with special industrial applications. The main types of coal are liquefaction coal, gasification purpose coal, coking coal and special high-element coal. Based on the coal quality evaluation of coal and the use of coal graded quality, this paper has sorted out the key evaluation indicators and evaluation parameters of special …

Technology And Practice For Deep Cbm Fracturing In Eastern Ordos Basin, Wang Xuxing, Wang Xingzun, Guo Bumin, Yuan Zheng, Feng Qing

Coal Geology & Exploration

The resources of deep coalbed methane buried at depth of more than 1 200 m in the eastern Ordos basin are rich and the key point for further exploration and development of CBM in the future. Compared with shallow CBM fracturing, there are many challenges in deep CBM fracturing such as with high situ stress, high closure stress, breakdown pressure as well as complex mechanical parameters of rock. Combined with the existing practice of CBM fracturing, taking the deep CBM buried at depth of about 2 000 m in the eastern Ordos basin as an example, tubing+ circulating SSD +packer …

Application Of Improved Hierarchic Analytic Process In The Classification Of Mine Hydrogeological Types, Wang Tiantian, Jin Dewu, Yang Jian, Liang Xiangyang

Coal Geology & Exploration

The classification of mine hydrogeological type is an important part of mine hydrogeology work. It is of great significance to analyze water filling conditions, evaluate water hazard and guide mine water prevention work. In order to evaluate mine hydrogeological conditions, this paper introduced optimal transfer matrix to improve hierarchic analytic process, and then applied this method to classify mine hydrogeological types. Taking four pairs of active mines in Hujierte mining area of Inner Mongolia as an example, the evaluation index system for classification of mine hydrogeological types was built on the basis of analysis of the hydrogeological conditions, then theoretical …

Design And Application Of Drilling Rod Vibration Frequency Measurement System, Liu Naipeng, Hu Yule, Wang Wei

Coal Geology & Exploration

During drilling, resonance is generated when the natural frequency of the drilling rod is consistent with the external excitation frequency. This will cause fatigue-failure of the drilling rod and serious consequences. To avoid this, a drilling rod vibration measurement system based on Micro-Electro-Mechanical System was designed. This system uses the three-axis acceleration sensor to measure the acceleration of the drilling rod in three directions. The upper computer software written in LabVIEW can storage, upload, display and process data. Then the fast Fourier Transform was taken to analyze the vibration frequency of the drilling rod. Finally the system is installed on …

Elastic Mechanics Solution Of Water Proof Key Layer In Coal Seam Floor Under High Water Pressure, Wang Yan, Yao Duoxi, Lu Haifeng

Coal Geology & Exploration

Aiming at the problem of water resisting capacity of the key layer in seam floor under the action of high pressure water, the key stratum was simplified as a fixed beam. The stress and displacement were calculated by the stress function method and the semi inverse method respectively. The results of two calculations were compared with the FLAC^3D results. The results show that the stress and displacement obtained by the stress function method are more appropriate than those calculated by the FLAC^3D method. It is suggested that for elastic mechanics analytic method of the fixed beam of the …

Integrated Identification Of Sequence Boundary Through Outcrop, Seismic With Logging And Geochemistry: A Case Of Jurassic In Northeastern Margin Of Ordos Basin, Zhang Tianfu, Zhang Yun, Cheng Yinhang, Miao Peisen, Ao Cong, Jin Ruoshi, Duan Lianfeng, Duan Xiaolong

Coal Geology & Exploration

Jurassic strata is mainly rock series containing coal and uranium in Ordos basin. The recognition of Jurassic sequence interfaces were mainly relied on the field outcrop, logging lithology of unconformity surface or the sedimentary discontinuity. However, it is tend to experience human recognition of randomness in the sequence interfaces recognition without macroscopic characteristics. Therefore, based on routine identification work such as outcrop profile and electrical curve of nearly 1 000 boreholes, combined with vertical changes of two-dimensional seismic profile and chemical index of alteration(CIA), three long-term cycle sequence interfaces(TSB1-TSB3) and seven medium-term cycle sequence interfaces(SB1-SB7) were finally identified in Jurassic …

Response Relation Between Fracturing Curve And Reservoir Pollution Degree Of Coalbed Methane Wells, Zhuang Dengdeng, Wang Yanbin, Tao Chuanqi, Chen Yan

Coal Geology & Exploration

In order to study the relationship between response curve and the pollution degree of fractured reservoir, taking Shizhuang block in Qinshui basin as an example, wells with different sensitivity of reservoir in the block were selected, through comparison of the difference of the dropping trace characteristics after the hydraulic curve reaches the fracture pressure in the fracturing curves of fracturing operation in different wells, the response law of hydraulic dropping trace and the reservoir sensitivity was summed up. Then in the same block according to the dropping trace of the hydraulic curves, the sensibility of reservoir was judged in several …

Iron Fertilization With Enhanced Phytoplankton Productivity Under Minimal Sulfur Compounds And Grazing Control Analysis In Hnlc Region, Tai-Jin Kim, G. H. Hong, D. G. Kim Kim, Mark Baskaran

Environmental Science and Geology Faculty Research Publications

The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the im- proved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved …

Short Communication: Challenges And Applications Of Structure-From-Motion Photogrammetry In A Physical Model Of A Braided River, Peter Ashmore, Pauline Leduc, Sarah Peirce

Geography & Environment Publications

For extending the applications of structure-from-motion (SfM) photogrammetry in river flumes, we present the main challenges and methods used to collect a large dataset ( > 1000 digital elevation models, DEMs) of high-quality topographic data using close-range SfM photogrammetry. Automatic target detection, batch processing, and considerations for image quality were fundamental to the successful implementation of the SfM technique on such a large dataset, which was used primarily for capturing details of gravel-bed braided river morphodynamics and sedimentology. While the applications of close-range SfM photogrammetry are numerous, we include sample results from DEM differencing, which was used to quantify morphology change …

Geoarchaeological Evidence Of Middle-Age Tsunamis At Stromboli And Consequences For The Tsunami Hazard In The Southern Tyrrhenian Sea, M. Rosi, S. T. Levi, M. Pistolesi, A. Bertagnini, D. Brunelli, V. Cannavo, A. Di Renzoni, F. Ferranti, A. Renzulli, D. Yoon

Publications and Research

Large-scale landslides at volcanic islands are one of the most dangerous geological phenomena, able to generate tsunamis whose effects can propagate far from the source. However, related deposits are scarcely preserved on-land in the geologic records, and are often difficult to be interpreted. Here we show the discovery of three unprecedented well-preserved tsunami deposits related to repeated flank collapses of the volcanic island of Stromboli (Southern Italy) occurred during the Late Middle Ages. Based on carbon datings, on stratigraphic, volcanological and archaeological evidence, we link the oldest, highest-magnitude investigated tsunami to the following rapid abandonment of the island which was …

Elastic Plastic Self-Consistent (Epsc) Modeling Of San Carlos Olivine Deformed In A D-Dia Apparatus, Pamela C. Burnley, Shirin Kaboli

Geoscience Faculty Research

We present a suite of low strain deformation experiments conducted on polycrystalline San Carlos olivine in a deformation DIA apparatus at temperatures ranging from 440 to 1106 °C at pressures between 3.8 and 4.6 GPa. The deformation behavior was monitored using in situ diffraction of white synchrotron X‑rays. The experiments were conducted at a slow strain rate of ~5 × 10–6/s so as to allow the initial elastic behavior to be closely monitored. For each experiment, we fit the diffraction data using elastic plastic self-consistent (EPSC) models. We find that to model the experiments we must incorporate an isotropic deformation …

Observational Time Series For Lakes Azuei And Enriquillo: Surface Area, Volume, And Elevation, Mahrokh Moknatian, Michael Piasecki

Publications and Research

In this report, we present historical time series of surface area, volume, and elevation for lakes Azuei (Haiti) and Enriquillo (Dominican Republic). The intention is to present a history of the lakes’ levels for both bodies of water as derived from Landsat imagery that is augmented by reports and narratives that reach further back in time. We also summarize lake level time series data collected and developed through various other efforts and compare these data sets to our time series. The time series contains 45 years’ worth of data ranging from 1972 to 2017 which we developed from Landsat imagery …

Short Communication: The Topographic Analysis Kit (Tak) For Topotoolbox, Adam M. Fortes

Faculty Publications

Quantitative analysis of digital topographic data is an increasingly important part of many studies in the geosciences. Initially, performing these analyses was a niche endeavor, requiring detailed domain knowledge and programming skills, but increasingly broad, flexible, open-source code bases have been developed to increasingly democratize topographic analysis. However, many of these analyses still require specific computing environments and/or moderate levels of knowledge of both the relevant programming language and the correct way to take these fundamental building blocks and conduct an efficient and effective topographic analysis. To partially address this, we have written the Topographic Analysis Kit (TAK), which leverages …

Assessing Landscape Scale Heterogeneity In Irrigation Water Use With Remote Sensing And In Situ Monitoring, T. Foster, I. Z. Goncalves, I. Campos, C. M.U. Neale, N. Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Understanding how irrigation is used across agricultural landscapes is essential to support efforts to grow more food while reducing pressures on limited freshwater resources. However, to date, few studies have analyzed the underlying spatial and temporal variability in farmers’ individual water use decisions at a landscape scale.Wecompare estimates of irrigation water requirements derived using state-of-the-art remote sensing models with metered abstraction records for 1400 fields over a 13 year period in the US state of Nebraska, one of the world’s most intensively irrigated agricultural regions. Weshow that farmers’ observed water use decisions often diverge significantly from biophysical estimates of crop …

2018 Long-Term Summary Of Kentucky Forage Variety Trials, Gene L. Olson, S. Ray Smith, Jimmy C. Henning, Christopher D. Teutsch

Forage Symposium at the Kentucky Cattlemen’s Convention

Forage crops occupy approximately 7 million acres in Kentucky. Forages provide a majority of the nutrition for beef, dairy, horse, goat, sheep, and wildlife in the state. In addition, forage crops play an environmentally friendly role in soil conservation, water quality, and air quality. There are over 60 forage species adapted to the climate and soil conditions of Kentucky. Only 10 to 12 of these species occupy the majority of the acreage, but within these species there is a tremendous variation in varieties.

This publication was developed to provide a user-friendly guide to choosing the best variety for producers based …

Topovar90m: Global High-Resolution Topographic Variables For Environmental Modeling, Giuseppe Amatulli Dr.

Yale Day of Data

Topographical relief involves the vertical and horizontal variation of the Earth's terrain and it drives processes in hydrology, climatology, geography and ecology. Its assessment and characterization is fundamental for various types of modeling and simulation analysis. In this regard, the Multi-Error-Removed Improved Terrain (MERIT) Digital Elevation Model (DEM) currently provides the best high-resolution DEM globally available, at a 3 arc-second resolution (90m), due to the removal of multiple error components from the underlying SRTM3 and AW3D30 DEMs. To depict topographical variations worldwide, we developed a new dataset comprising different terrain features derived from the MERIT-DEM. The fully standardized topographical variables …

Effect Of Hot Water Treatment Of In-Shell Pecans On Physicochemical Properties And Consumer Acceptability Of Roasted Pecan Kernels, Karuna Kharel, Witoon Prinyawiwatkul, Veerachandra K. Yemmireddy, Charles J. Graham, Achyut Adhikari

School of Earth, Environmental, & Marine Sciences Faculty Publications

The effect of hot water pre-treatment of in-shell pecans on physicochemical properties, consumer acceptance and purchase intent of dehulled and roasted kernels was evaluated. In-shell pecans were first subjected to hot water at 70, 80 and 90 °C for 8.6, 6.6 and 4.6 min respectively and kernels were later dry roasted at 160 °C for 10 min. The physicochemical properties of hot water treated and untreated nuts, before and after roasting were determined. Furthermore, consumer acceptance and purchase intent of the roasted kernels were determined. Hot water treatment, alone and subsequent roasting had minimal effect on pecans’ physicochemical properties. Consumers …

Late Pleistocene Glaciation In The Mosquito Range, Colorado, U.S.A.: Chronology And Climate, Keith A. Brugger, Benjamin J.C. Laabs, Alexander Reimers, Noah Bensen

Geology Publications

New cosmogenic ¹⁰Be surface exposure ages from seventeen moraine boulders in the Mosquito Range suggest that glaciers were at their late Pleistocene (Pinedale) maximum extent at ~21–20 ka, and that ice recession commenced prior to ~17 ka. These age limits suggest that the Pinedale Glaciation was synchronous within the Colorado Rocky Mountain region. Locally, the previous (Bull Lake) glaciation appears to have occurred no later than 117 ka, possibly ~130 ka allowing for reasonable rock weathering rates. Temperature-index modeling is used to determine the magnitude of temperature depression required to maintain steady-state mass balances of seven reconstructed glaciers at …

Experiment Study Of Lateral Unloading Stress Path And Excess Pore Water Pressure On Creep Behavior Of Soft Soil, Wei Huang, Kejun Wen, Dongsheng Li, Xiaojia Deng, Lin Li, Haifei Jiang, Farshad Amini

Civil and Architectural Engineering Faculty Research

The unloading creep behavior of soft soil under lateral unloading stress path and excess pore water pressure is the core problem of time-dependent analysis of surrounding rock deformation under excavation of soft soil. The soft soil in Shenzhen, China, was selected in this study. The triaxial unloading creep tests of soft soil under different initial excess pore water pressures (0, 20, 40, and 60 kPa) were conducted with the K0 consolidation and lateral unloading stress paths. The results show that the unloading creep of soft soil was divided into three stages: attenuation creep, constant velocity creep, and accelerated creep. The …

Isolution 1.0: An Isotope Evolution Model Describing The Stable Oxygen (Δ18O) And Carbon (Δ13C) Isotope Values Of Speleothems, Michael Deininger, Denis Scholz

International Journal of Speleology

Stable oxygen and carbon isotope ratios (δ¹³C and δ¹⁸O) are the most applied climate and environmental proxies in speleothems allowing to infer past changes in cave drip water δ¹³C and δ¹⁸O related to climate and environmental variations from above the cave. However, disequilibrium isotope fractionation processes can modify δ¹³C and δ¹⁸O values in speleothems, which is in most cases difficult to estimate due to inter-dependencies on various cave specific parameter. To better understand the effect of these disequilibrium isotope fractionation processes proxy system models were developed in recent …

A Multi-Proxy Approach To Refining Paleotempestology Records On The Northern Gulf Of Mexico Coast, Marianne Elizabeth Dietz

LSU Doctoral Dissertations

Reconstructing pre-historic hurricane activity is typically accomplished through the analysis of sandy overwash deposits identified in coastal lake settings. This method has been used successfully in many parts of the world and can extend the hurricane record thousands of years into the past. However, this approach also has its limitations. This dissertation addresses some of the limitations associated with geologic proxies used to reconstruct hurricane landfalls in the absence of historic data and tests new proxies for the identification of hurricane-derived overwash deposits. Modern storm deposits from two sites on the northern Gulf of Mexico coast are analyzed in detail …

Assessing The Evolution Of Soil Moisture And Vegetation Conditions During A Flash Drought–Flash Recovery Sequence Over The South-Central United States, Jason A. Otkin, Yafang Zhong, Eric D. Hunt, Jeff Basara, Mark Svoboda, Martha C. Anderson, Christopher Hain

National Drought Mitigation Center: Faculty Publications

This study examines the evolution of soil moisture, evapotranspiration, vegetation, and atmospheric conditions during an unusual flash drought–flash recovery sequence that occurred across the south-central United States during 2015. This event was characterized by a period of rapid drought intensification (flash drought) during late summer that was terminated by heavy rainfall at the end of October that eliminated the extreme drought conditions over a 2-week period (flash recovery). A detailed analysis was performed using time series of environmental variables derived from meteorological, remote sensing, and land surface modeling datasets. Though the analysis revealed a similar progression of cascading effects in …

Landslides Near Enguri Dam (Caucasus, Georgia) And Possible Seismotectonic Effects, Alessandro Tibaldi, Paolo Oppizzi, John S. Gierke, Thomas Oommen, Nino Tsereteli, Zurab Gogoladze

Department of Geological and Mining Engineering and Sciences Publications

The Enguri dam and water reservoir, nested in the southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that affect a subaerial area of 1.2 km². The head scarp affects the Jvari–Khaishi–Mestia main road with offsets of man-made features that indicate slip rates of 2–9 cm yr⁻¹. Static, pseudostatic and Newmark analyses, based on field and seismological data, suggest different unstable …

Soil Cover Of The Highlands Of Uzbekistan, R. Kuziev, G Yuldashev

Scientific journal of the Fergana State University

In the article materials on the study of mountain light brown meadow-steppe soils of highlands of Uzbekistan are prsented. Geography, properties and resource of light brown soils are given

Geochemistry Of Irrigated Meadow Sasa Soils, M. Isagaliev, Kh. Abdukhakimova,, M Obidov [email protected] Fergana State University, Ferghana, Str,Murabbiylar 19

Scientific journal of the Fergana State University

In the article the content of chemical elements in the Clarke concentration, the Clarke dispersion and Clarke scattering in irrigated meadow sasa soils is tested, as well as the logarithms of chemical elements, which differentiates between -2.0-4.41 are calculated

Dynamics Of Arzyk-Shokh Meadow Sasa Soils Under Influence Of Irrigation, V. Isakov, U Mirzaev

Scientific journal of the Fergana State University

In the article evolutionary development of arzyk-shokh meadow sasa soils of Central Fergana under the influence of anthropogenic factors associated with irrigation is updated

Soil Moisture Monitoring Using Remote Sensing Data And A Stepwise-Cluster Prediction Model: The Case Of Upper Blue Nile Basin, Ethiopia, Getachew Ayehu, Tsegaye Tadesse, Berhan Gessesse, Yibeltal Yigrem

National Drought Mitigation Center: Faculty Publications

In this study, a residual soil moisture prediction model was developed using the stepwise cluster analysis (SCA) and model prediction approach in the Upper Blue Nile basin. The SCA has the advantage of capturing the nonlinear relationships between remote sensing variables and volumetric soil moisture. The principle of SCA is to generate a set of prediction cluster trees based on a series of cutting and merging process according to a given statistical criterion. The proposed model incorporates the combinations of dual-polarized Sentinel-1 SAR data, normalized difference vegetation index (NDVI), and digital elevation model as input parameters. In this regard, two …