Earth Sciences Commons^™

Methodology And Integration For Dynamic Safety Assessment And Early Warning Of Drilling Sites For Emergency Rescue After Underground Space Collapse, Xie Zhongzhi, Zhang Guohua, Wei Xingtong, Zhang Ning, Wang Xiaotian, Ni Xiaoyang, Zhou Zhengwen, Wang Xianze

Coal Geology & Exploration

Objective IGiven the lack of methods for dynamic safety assessment related to disasters in drilling site environments for emergency rescue after underground space collapse, this study proposed a multisource data-driven methodology for dynamic safety assessment and real-time early warning. Methods By comprehensively considering the disaster-inducing environment and disaster-causing factors at drilling sites for emergency rescue, this study established the safety assessment indices of the environment and their grading system. By integrating multi-source data on surrounding rock deformation, gas concentration, and drilling rig vibration, this study developed a safety assessment method through combination weighting achieved using the analytic hierarchy process (AHP) …

Digital Rock Modeling And Elastic Simulations Of Fractured-Vuggy Carbonate Reservoirs, Zhu Wei, Zhao Luanxiao, Wang Yirong

Coal Geology & Exploration

Objective The Tarim Basin exhibits extensively distributed deep fractured-vuggy carbonate reservoirs. Therefore, determining the seismic and petrophysical characteristics of carbonate reservoirs with a fracture and vug system will provide significant guidance for the exploration, discovery, drilling, and exploitation of favorable reservoirs in the basin. Variations in the filling state of dissolution fractures and vugs will lead to significantly different elastic and attenuation characteristics of the reservoirs. Methods Based on geological insights into the geometric structural and filling characteristics of the dissolution fracture-vug system in the outcrop sections of carbonate strata in the Tarim Basin, this study proposed a digital rock …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Pseudo-2d Mt Inversion Technique For Small-Frame Tem And Its Application In Advance Geological Prediction, Han Ziqiang, Wanma Longzhi, Li Xiangfeng, Yang Yongqiang, Zhu Xiaoming, Luo Chengxian, Tang Li

Coal Geology & Exploration

Objective To address the bottlenecks of low computational efficiency and impracticality of multi-dimensional inversion in the advance geological prediction based on the transient electromagnetic method (TEM), this study developed a pseudo-two-dimensional (2D) magnetotelluric (MT) inversion technique for small-frame TEM based on time-frequency transformation. Methods First, this study corroborated the significant similarity between the late-time apparent resistivity derived using small-frame TEM and the Cagniard apparent resistivity in the MT method under the parameters commonly used in advance geological prediction. Then, the optimal time-frequency transformation coefficient (C_TF) was introduced to achieve a rapid conversion from the late-time apparent resistivity …

Fracturing Evolution Mechanisms Of Eroded Coals Under The Temperature Effect Of The Co2-H2O System, Lin Baiquan, Shi Yu, Liu Ting, Shen Yang, Huang Tao

Coal Geology & Exploration

Background Injecting hot flue gas produced and discharged by gas-fired power plants into deep coal seams where gas is difficult to extract enjoys dual benefits: gas production growth and geologic CO₂ sequestration. However, there is an urgent need to determine the impact of the heat-carrying property of hot flue gas on the stability of coal reservoirs. To address this issue, the key is to clarify the fracturing evolution mechanisms of eroded coals under the temperature effect of the CO₂-H₂O system.Methods Using the independently built platform of CO₂-H₂O-coal interactions that consider …

Impacts Of Co2/Ch4/N2 Adsorption/Desorption On The Macromolecular Structure Of Anthracite: Insights From In Situ Raman Spectroscopy, Wang Tian, Pan Jienan, Li Meng, Wang Kai, Tang Zhuyun, Cheng Nannan, Hou Quanlin

Coal Geology & Exploration

Objective and Methods The adsorption/desorption of coalbed methane (CBM) not only induces the macroscopic deformations of coals but also significantly alters their macromolecular structures, with different gases exhibiting greatly varying mechanisms and influence degrees. Utilizing an independently developed in situ laser Raman spectroscopy system, this study revealed the differential structural responses and mechanisms of anthracite under CO₂, CH₄, and N₂ injection. Results and Conclusion Experimental results indicate that gas injection led to notable blue shifts in the D₄, D, D₃, and G peaks characterizing the microcrystalline structures of coals. In contrast, …

Advances In Research On Geological Evaluation Of Compressed Air Energy Storage In Underground Gas Storage Facilities, Jiang Wen, Huang Leqing, Zhang Songhang, Ma Huiying

Coal Geology & Exploration

Background Against the backdrop of achieving peak carbon dioxide emissions and carbon neutrality globally, renewable energy has developed rapidly and is gradually changing the world's energy mix. However, the intermittent and fluctuating nature of photovoltaic and wind power energy is prone to cause grid frequency fluctuations and reduced power supply reliability. Compressed air energy storage (CAES) technology has emerged as the key to the stable operation of the green power grid thanks to its large capacity and low cost.Methods Based on a systematic review of domestic and international literature in recent years, this study organizes the current theoretical and …

Log-Based Identification Of Sedimentary Facies In Coal Measures In The Southern Wuxiang Block, Shanxi Province, China, Jin Yi, Tian Yunqing, Song Huibo, Hu Bin, Yu Zhenfeng

Coal Geology & Exploration

Objective The Carboniferous and Permian coal-bearing strata in the southern Wuxiang block, Qinshui Basin, Shanxi Province, China contain abundant coalbed methane (CBM) resources. To develop intelligent discrimination technology for CBM exploration in this block, it is necessary to establish lithology discrimination criteria based on log data, reveal the response relationships between logging and sedimentary facies, and determine sedimentary patterns. Methods Using a comprehensive analysis of lithologies, sedimentary facies, and logging facies, this study systematically investigated the distributions of logging and sedimentary facies in the Shanxi and Taiyuan formations—the primary coal-bearing strata in the southern Wuxiang block. By comprehensively analyzing the …

Spatial Distribution Of Coalbed Methane Migration Pathways And Selection Of Optimal Target Areas For Coalbed Methane Extraction For Abandoned Mines, Liu Qinjie, Yang Youxing, Wu Benniu, Duan Minke, Deng Zhuoyue, Guo Chenye, Sun Qiang

Coal Geology & Exploration

Objective and Methods The spatial distribution and long-term evolution of effective migration pathways determine the migration pathways of residual coalbed methane (CBM) in abandoned mines. Furthermore, they provide an important basis for selecting the optimal target areas for CBM extraction drilling in abandoned mines and maximizing extraction efficiency. This study investigated the first mining area at the first horizontal elevation of the Songzao Coal Mine in Chongqing. Using a comprehensive approach that integrated theoretical analysis, numerical simulations, and physical simulation experiments using similar materials, this study systematically examined the distribution patterns of effective CBM migration pathways in abandoned mines under …

Geochemical Characteristics And Genesis Of Element Enrichment Of Niobium-Rich-Rare Earth Metal Layer In Longtan Formation Of Zhina Coalfield, Ding Yunlong, Wang Fangfa, Li Bi, Tang Lifang, Yang Yi, Li Shangyuan, Wang Xiaofang, Zou Yinhong, Wang Yang

Coal Geology & Exploration

Background With the increasing demand for strategic metals and the gradual depletion of traditional metal deposit resources, coal and coal-bearing rock series are considered to be potential sources of rare metals, and coal series associated has become one of the main directions of current mineral exploration. A set of coal measure strata rich in niobium (Nb) and rare earth elements (REE) has been found in Zhina coalfield, western Guizhou and the contents of Nb and REE are as high as 334.89 μg/g and 1014.51 μg/g, respectively. This discovery is of great significance to the theoretical study of coal measure metal …

Macroscopic Failure Characteristics And Seepage Pattern Of Damaged Goaf-Side Coal Pillars Under Confined Water Accumulation, Liu Weitao, Chen Dongqi, Liu Yuben, Du Yanhui, Zhao Jiyuan

Coal Geology & Exploration

Background The method of supporting roadways using small coal pillars has been widely applied in China. As a result, the stability of goaf-side coal pillars affects mining safety. Resulting from multiple disturbance effects, coal pillars tend to contain various types of damage fractures. The confined water environment in goaves with water accumulation might cause the instability failure of damaged goaf-side coal pillars. Methods To investigate the impacts of the damage fracture structure on coal stability, this study introduced the concept of relatively stable initial damage fractures. Based on the theory of damage mechanics, this study constructed hydro-mechanical-damage (HMD) coupling models …

3d Advanced Geological Prediction Based On Reflected Seismic Waves And Its Application Effects, Cai Sheng

Coal Geology & Exploration

Objective For the advance geological prediction of tunnels based on reflected seismic waves, the traditional 2D observation method tends to cause spatial positioning deviations of anomalies. To overcome this limitation, this study developed a 3D seismic wave-based advance geological prediction method according to the actual geometries of tunnels. Methods Using the technical path consisting of theoretical analysis, numerical simulation, and engineering verification, this study solved key technical challenges including 3D wavefield reconstruction, spatial modeling, and migration imaging in the 3D detection system. Based on the principle of geometric seismology, this study demonstrated the enhancement effects of 3D observation on the …

A Time Series Forecasting Model Integrating Spatial Features For Inter-Borehole Resistivity And Its Application, Wang Jianghong, Liu Shuo, Wang Gang, Xue Wuqiang, Li Bofan

Coal Geology & Exploration

Background Mine resistivity prediction serves as a core technique for water hazards monitoring in coal mines. However, due to sparse monitoring points and insufficient spatial resolution, conventional prediction approaches fail to capture dynamic resistivity variations under complex geological conditions.Objective and Methods To address this challenge, this study developed a deep learning-based time series forecasting model integrating spatial features for inter-borehole resistivity. Using a prediction framework constructed based on long short-term memory (LSTM) and critical spatial monitoring points selected through Pearson correlation analysis, this model (also referred to as the LSTM model) enabled high-precision prediction of resistivity in unknown areas. …

Hybrid Differentiator-Based Method For Estimating The Drilling Speed Of A Vehicle-Mounted Drilling Rig During Surface Drilling For Mine Rescue, Wang Yunfei, Zhao Jiyun, Hu Yongjie, Zhang Zongyang, Pan Xiaochen

Coal Geology & Exploration

Background Vehicle-mounted drilling rigs (VMDRs), key devices in surface drilling for mine rescue, directly connect the ground and underground disaster-hit areas through vertical drilling, thereby creating rescue channels for trapped people. In this case, the drilling speed of VMDRs serves as an important indicator for evaluating surface drilling operations. However, directly determining the drilling speed is challenging due to the limitations of position sensors. Methods This study developed an estimation method based on a new hybrid differentiator (NHD), allowing the drilling speed to be calculated using measurable displacement signals. First, a continuous switching function was devised, and its convergence characteristics …

Parameter Characteristics And Rock-Breaking Mechanisms Of Horizontal Drilling Of Underground Collapsed Bodies In Coal Mines, Yao Ningping, Dou Xuqian, Han Zhaoyang, Zhang Guohua, Sun Yuchen, Li Hao, Wang Li

Coal Geology & Exploration

Objective With continuously increasing coal mining depth, the risks of hazards such as roof collapse and personnel entrapment caused by high in situ stress and mining-induced pressure have significantly intensified. Drilling emerges as a key means of rapidly establishing rescue passageways. However, the drilling process tends to face multiple challenges, including complex geological structures, unstable collapsed bodies, and low drilling efficiency. Methods This study aims to reveal the rock-breaking mechanisms during the drilling of collapsed bodies, optimize drilling parameters to ensure reliable borehole formation, and achieve efficient drilling of collapsed bodies. To this end, this study developed a large-scale experimental …

The Hydro-Geomorphic Response Of The Ephemeral Lower Nahal Tzalmon Stream To Experimental Flow Releases Towards Replenishment Of The Sea Of Galilee, Ne Israel, Nathaniel Bergman, Noam Greenbaum, Eyal Weinberg, Iyad Swaed

Geology Faculty Publications and Presentations

Study region:

The Sea of Galilee’s western watershed includes the Lower and Upper Galilee subregions in northern Israel. Nahal Tzalmon stream (110 km2) is one of the major gravel-bed channels draining those subregions into the lake. Study focus: The study focus was to monitor the immediate effects of introducing “hungry water” from the newly mega-project of the “Reverse National Water Carrier” (RNWC). The project was designed to convey desalinated water from the Mediterranean coastal desalination plants through a 5 km open channel into the lower Nahal Tzalmon stream in order to replenish the Sea of Galilee. During a 2-day experimental …

Geochemical And Thermobarometric Constraints On Granite Crystallization, Glenn Tristan Thompson

Dissertations - ALL

Granite is ubiquitously recognized by many people due to its common use as a building material and its abundance in the Earth's continental crust. From countertops to library steps, and as a source of economically important elements, granitic rocks are deeply intertwined with human development. Defining the pressure and temperature (P– T) conditions under which granitic composition magmas crystallize is critical for understanding their petrogenesis. This dissertation explores granite petrogenesis across three chapters, utilizing detailed analysis of rock-forming minerals, associated fluids, and geochemical variations to understand how compositional variability influences the lowest possible crystallization conditions. Chapter 1 investigates the physical …

Dissolution Mechanism Of Nonionic Polyether Surfactants In Supercritical Co2, Ning Xu, Yanling Wang, Baojun Bai, Shizhang Cui, Zan Gao, Yu Zhang, Di Li, Wenjing Shi, Wenhui Ding, Peixu Ma

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Polyoxyethylene ether is an efficient CO₂-philic compound with significant potential applications in CO₂ flooding, which requires CO₂-philic surfactants with high solubility in supercritical CO₂ (scCO₂). This study elucidates the molecular and atomic-level dissolution mechanism of the fatty alcohol polyoxyethylene ether (AEO) in scCO₂ by combining phase-behavior experiments and molecular dynamics simulations. The solubility of AEO in scCO₂ is measured using a semiconductor laser. AEO containing three polyoxyethylene (EO) groups exhibited the highest solubility in scCO₂.The solubility of AEO in scCO₂ decreased with an increase in the number …

Does Bubble Nucleation Occur Heterogeneously In Magmas Feeding Explosive Rhyolite Eruptions? Insights From The Rock Magnetic Properties Of Pumice, Kelly N. Mccartney, Julia E. Hammer, Thomas Shea, Stefanie Brachfeld, Thomas Giacheetti, Bruce F. Houghton

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Nanometer-scale titanomagnetite crystals have been detected in nominally aphyric rhyolite pumice, but whether they are numerous enough to impact bubble nucleation in explosive silicic volcanism was unresolved. This study examines sub-micron crystals using rock magnetic techniques, Rhyolite-MELTS modeling, and physical characterization. We analyzed pumice from four eruptions spanning wide ranges in intensity, storage depth, and bubble number density (1016 to 1013 m−3 liquid): 1060 CE Glass Mountain, 1912 CE Novarupta, 232 CE Taupo, and 0.45 Ma Pudahuel. Calculations assuming monospecific assemblages of 10 and 1,000 nm cubic particles yield titanomagnetite number densities of 1021 to 1013 m−3 dense rock equivalent, …

Collaborative Research: Bocp-Implementation: Us-China: Multi-Scale, Multi- Proxy, Integrative Investigation Of Functional Biodiversity On A Changing Proterozoic Planet, Carol Dehler

Funded Research Records

No abstract provided.

Spectral Mixture Analyses Of Hematite-Rich And Clay-Bearing Terrains In Meridiani And Oxia Planum, Mars, Thomas Jake Condus

Arts & Sciences Graduate Student Theses and Dissertations

Minerals have characteristic absorption features in the visible and near-infrared wavelength range, which can be detected in remotely sensed observations using methods such as spectral parameter maps or modeled via spectral mixtures. My dissertation uses both methods on orbital and ground-based single-scattering albedo data to assess the surface compositions of Meridiani Planum and Oxia Planum, regions of Mars that are rich in secondary minerals. A probabilistic approach to spectral unmixing was adopted to account for the nonuniqueness of model solutions, with endmember abundance and grain size maps being produced for Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) orbital images. For …

New Precipitation Is Scarce In Deep Soils: Findings From 47 Forest Plots Spanning Switzerland, Emily I. Burt, Scott T. Allen, Sabine Braun, Simon Tresch, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As precipitation infiltrates into soils, it can recharge them, displace previously stored waters, or bypass already-filled pores. Using 3,697 δ2H and δ18O measurements of water collected nearly monthly over >3 years in 47 forest plots across Switzerland, we present a systematic investigation of the controls on mobile soil water transport. We quantified the lags and damping of water as it percolates downward using young water fraction analysis (Fyw), and the fractions of soil water composed by precipitation that fell within the previous month (new water fractions, Fnew). The Fnew of water sampled in surface soils ranged …

Hindcasting The Occurrence Time Of Major Earthquakes Using Machine Learning And Time Series Analysis, Rubidha Devi D

Theses and Dissertations

An earthquake is an intense shaking of the ground that typically occurs when tectonic plates move beneath the surface of the Earth. Scientists analyze historical seismic records and geophysical and atmospheric signs to build models estimating the probability of major earthquakes by detecting patterns and anomalies in data such as ground deformation and seismic waves. This study would help in predicting earthquakes to minimize risks of people and buildings.

The present study investigates the devastating earthquakes along the Chilean subduction zone in South America, linking non-seismic data to machine learning predictions of Outgoing Longwave Radiation (OLR) and Relative Humidity (RH) …

Geol 12 Natural Disasters Syllabus, Anestoria Shalkowski

Open Educational Resources

Hazards are events which have the capabilities to damage property and or life. Understanding natural hazards and how these can become disasters are important in reducing the impacts of such events. This syllabus provides a description of the material to be examined and the expected student outcomes upon completion of the course.

The Future Intensification Of Hydrological Extremes And Whiplashes In The Contiguous United States Increase Community Vulnerability, Surendra Maharjan, Wenzhao Li, John D. Bolten, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydroclimatic whiplash rapid shifts between drought and flood poses growing risks to U.S. communities. Here, we assess historical extremes and future projections using a normalized streamflow metric: the annual mean flow’s deviation from the 1981–2020 average, expressed as a fraction of that average. This metric is applied to United States Geological Survey records and Localized Constructed Analogs downscaled projections under Representative Concentration Pathways 4.5 and 8.5. Results reveal sharp regional disparities, with drought deficits exceeding 300% of normal flow during multi-year droughts. By linking hydrologic outcomes with the Federal Emergency Management Agency’s National Risk Index, we find that counties facing …

Receiver Function Imaging Of The Mantle Transition Zone Beneath The East Sayan Mountains And Adjacent Area In Central Asia: Implications For Lithospheric Drip And Intraplate Cenozoic Volcanism, Yangyang Liao, Kelly H. Liu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To provide constraints on the formation mechanisms of intracontinental volcanisms and intriguing lithospheric thickness variations in the East Sayan Mountains and surrounding areas, we stack P-to-s receiver functions to image the 410-km and 660-km discontinuities. Mantle transition zone (MTZ) thickening observed in a continuous area is attributable to ancient slab remnants, and Cenozoic volcanisms in the peripheral area can be explained by slab dehydration. The thinning of the MTZ in the Tuva-Mongolian Massif can be explained by mantle upwelling branches induced by slab subduction. Our results reveal an approximately circular area in the MTZ that is significantly thicker than usual, …

The Compositional And Dynamical Properties Of Exoplanets, Cody James Shakespeare

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solid surface density profile of protoplanetary discs, and the composition of these solids, can be formed through sequential condensation models of dust precipitating from the cooling gas of the solar nebula. I continue developing a code that reproduces the chemical compositions of most chondrites as well as the bulk compositions of the rocky planets using our partial condensation model with an evolving disc. I extend this validated code to exoplanet systems with different initial elemental ratios, like the carbon-to-oxygen ratio and estimated stellar abundances over the age of the universe. I have improved this dust condensation code to include …

Multi-Sensor Remote Sensing Captures Geometry And Slow-To-Fast Sliding Transition Of The 2017 Mud Creek Landslide, Alexander L. Handwerger, Pascal Lacroix, Andrew F. Bell, Adam M. Booth, Mong-Han Huang, Simon M. Mudd, Roland Bürgmann, Eric J. Fielding

Geology Faculty Publications and Presentations

Landslides pose a significant hazard worldwide. Despite advances in landslide monitoring, predicting their size, timing, and location remains a major challenge. We revisit the 2017 Mud Creek landslide in California using radar interferometry, pixel tracking, and elevation change measurements from satellite and airborne radar, lidar, and optical data. Our analysis shows that pixel tracking of optical imagery captured the transition from slow motion to runaway acceleration starting ~ 1 month before catastrophic failure—an acceleration undetected by satellite InSAR alone. Strain rate maps revealed a new slip surface formed within the landslide body during acceleration, likely a key weakening mechanism. Failure …

Understanding Ore Deposit Scale Controls On Au Enrichment In Carlin-Type Au Mineralization: A High-Resolution Study Of The Rita K Deposit, Conner T. Callaway

UNLV Theses, Dissertations, Professional Papers, and Capstones

Controls on the distribution of gold (Au) within the Rita K Carlin-type deposit are poorly understood. The primary Au-bearing carbonate unit Wispy, is a bioturbated muddy limestone with debris flow clasts that range in size but are typically >5 cm occurring in the lower sections. The orebody is described as a syncline-anticline pair that hosts high-grade Au ore in the fold hinges. The spatial relationship between Au mineralization and fold hinges suggests that shortening due to folding is an important mechanism producing Au-enriched zones. However, the exact mechanism of Au enrichment and deposit-scale controls on Au distribution and fluid evolution …

Mechanisms Of Gold Enrichment In Seafloor Massive Sulfide Deposits: A Study On The Higashi-Aogashima Hydrothermal Field, Claudia Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The study of Seafloor Massive Sulfides (SMS) deposit formation is vital for assessing both the economic potential and environmental risks posed by future marine mining projects. Metal-rich SMS deposits form in hydrothermal vent systems within tectonically active regions, such as back-arc basins, where faults enhance crustal permeability, enabling fluid migration driven by magmatic heat sources at depth in the crust. Currently our understanding of SMS formation processes is based on bulk-rock geochemical and isotopic data, lacking the necessary spatial and temporal resolution to understand ore forming processes. As a result, critical gaps remain in understanding the exact mechanisms responsible for …