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2022

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Full-Text Articles in Geology

Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant Apr 2022

Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant

United States Geological Survey: Staff Publications

  1. Most applications of single-scale occupancy models do not differentiate between availability and detectability, even though species availability is rarely equal to one. Species availability can be estimated using multi-scale occupancy models; however, for the practical application of multi-scale occupancy models, it can be unclear what a robust sampling design looks like and what the statistical properties of the multi-scale and single-scale occupancy models are when availability is less than one.
  2. Using simulations, we explore the following common questions asked by ecologists during the design phase of a field study: (Q1) what is a robust sampling design for the multi-scale occupancy …


Processing Seismic, Gravity And Magnetic Data Over Diebold Knoll On Juan De Fuca Plate, Md Ariful Islam, Irina Filina Apr 2022

Processing Seismic, Gravity And Magnetic Data Over Diebold Knoll On Juan De Fuca Plate, Md Ariful Islam, Irina Filina

UNL Student Research Days Posters, Graduate

The Juan de Fuca plate is subducting beneath the North American plate along the Cascadia Subduction Zone. The CSZ is associated with multiple earthquakes, although compared to other subduction zones, it is less active. Many studies suggest that subduction will cause major mega thrust earthquake in near future, while others oppose this view. This project is focused on the Diebold Knoll on the JdF plate Various geophysical methods will be integrated to determine its origin and tectonic history.


A Tectonic Geomorphic Study Of Neotectonics And Seismic Hazard Of The Fold And Thrust Belt Complex Of Bengal Basin, Eastern Himalayan Range, Niroj Shrestha Apr 2022

A Tectonic Geomorphic Study Of Neotectonics And Seismic Hazard Of The Fold And Thrust Belt Complex Of Bengal Basin, Eastern Himalayan Range, Niroj Shrestha

Masters Theses & Specialist Projects

Tectonic activity continues to shape and create challenges for human populations in tectonically active areas. The Bengal Basin is one of the most important sedimentary basins of the Eastern Himalayan Range, aiding in one of the densely populated regions of the world. The basin is part of the tectonically active Himalayan Orogen that is undergoing oblique subduction between the Eurasian Plate and the Indian Plate. As a result of this subduction-related convergence, the eastern part of the Basin, particularly the Chittagong-Tripura Fold Belt (CTFB) and western part of the Indo-Burman Range (IBR) has structurally deformed into a series of mostly …


A Geospatial And Binomial Logistic Regression Model To Prioritize Sampling For Per- And Polyfluorinated Alkyl Substances In Public Water Systems, Sweta Ojha, Ying Li, Nader Rezaei, Ariel Robinson, Anna G. Hoover, Kelly G. Pennell Apr 2022

A Geospatial And Binomial Logistic Regression Model To Prioritize Sampling For Per- And Polyfluorinated Alkyl Substances In Public Water Systems, Sweta Ojha, Ying Li, Nader Rezaei, Ariel Robinson, Anna G. Hoover, Kelly G. Pennell

UK CARES Faculty Publications

As health‐based drinking water standards for per‐ and polyfluorinated alkyl substances (PFAS) continue to evolve, public health and environmental protection decision‐makers must assess exposure risks associated with all public drinking water systems in the United States (US). Unfortunately, current knowledge regarding the presence of PFAS in environmental systems is limited. In this study, a screening approach was established to: (1) identify and direct attention toward potential PFAS hot spots in drinking water sources, (2) prioritize sampling locations, and (3) provide insights regarding the potential PFAS sources that contaminate groundwater and surface water. Our approach incorporates geospatial data from public sources, …


Mineralogy, Isotope Geochemistry And Geothermometry Of The Lowry Deposit, Black Butte Copper Project, Meagher County, Montana, John Allard Apr 2022

Mineralogy, Isotope Geochemistry And Geothermometry Of The Lowry Deposit, Black Butte Copper Project, Meagher County, Montana, John Allard

Graduate Theses & Non-Theses

The Black Butte Copper Project is a sedimentary rock hosted, Cu-rich massive sulfide deposit hosted in rocks of the ca. 1.5-1.325 Ga Mesoproterozoic Belt Supergroup. Copper-bearing sulfides, mainly chalcopyrite and tennantite, are hosted in debris flows, black shale, dolostone and sedimentary pyrite layers of the Newland Fm. of the Lower Belt Group in the Helena Embayment, an E-W striking limb of the greater NNW trending Belt Basin. Mineralization is hosted within two separate but contemporaneous deposits, Johnny Lee, which hosts Cu sulfides in an upper and lower sulfide zone within sedimentary pyrite and debris flow conglomerates, and Lowry, where Cu …


Geology And Geochronology Of The East Dome Complex Within The Hog Heaven Volcanic Field, Flathead County, Montana, Ethan Coppage Apr 2022

Geology And Geochronology Of The East Dome Complex Within The Hog Heaven Volcanic Field, Flathead County, Montana, Ethan Coppage

Graduate Theses & Non-Theses

This study describes the style and timing of volcanic activity and mineralization in the East Dome Complex (EDC) of the 55-km2 Eocene-Oligocene Hog Heaven Volcanic Field (~36-30 Ma; HHVF) located in northwestern Montana. The HHVF consists of three NE-aligned, predominantly high-K rhyodacitic dome complexes (1.8-4.9 wt. % K2O; 63.2-72.9 wt. % SiO2) formed near the crest the Purcell Anticlinorium, a major Cordilleran fold-thrust belt structure deforming metasedimentary rocks of the Mesoproterozoic Belt Supergroup. Dome emplacement was controlled by a NE-striking fault associated with a pull-apart basin formed between two overlapping, NW-trending dextral oblique-slip faults. The objective of this study is …


Mineralogy And Fluid Inclusion Study Of The Marget Ann Mine Of The Butte Mining District, Silver Bow County, Montana, Tiffany Ostenburg Apr 2022

Mineralogy And Fluid Inclusion Study Of The Marget Ann Mine Of The Butte Mining District, Silver Bow County, Montana, Tiffany Ostenburg

Graduate Theses & Non-Theses

Butte, Montana, is a famous example of a zoned, polymetallic, porphyry-lode deposit. Whereas over a century of previous work has focused on the porphyry-style mineralization and centrally located, copper-rich lode deposits, relatively little has been written on the outer, silver-rich veins. The Marget Ann mine, in the northern portion of the district, was chosen for this study because of ease of access to the mine dumps as well as archived samples of high-grade vein mineralization. In addition, the Marget Ann mine is somewhat unique in Butte because gold has been found there and previously recorded in the veins. The main …


An Examination Of The Impacts Of Beaver Dam Mimicry Structures On Groundwater Surface-Water Interactions In Lower Mountain Riparian Systems, Mercedes D. Salazar Apr 2022

An Examination Of The Impacts Of Beaver Dam Mimicry Structures On Groundwater Surface-Water Interactions In Lower Mountain Riparian Systems, Mercedes D. Salazar

Graduate Theses & Non-Theses

Beaver dam analogs (BDAs) are a low cost, low disturbance stream restoration technique that may improve surface-water/groundwater interactions and wetland connectivity. BDAs are intended to imitate the effects of natural beaver dams by slowing stream velocity, promoting infiltration, increasing dry-season streamflow, aggrading the streambed, and capturing organic matter and other nutrients. This study was conducted to evaluate the degree to which these objectives were being met at a study site on Perkins Gulch, southwest Montana, USA. The Perkins Gulch study area can be summarized by four gauging sites that separate three reaches along the creek. By detailing background processes and …


Surface Water/Groundwater Interactions And Hydrogeochemical Characterization Of The Elkhorn Mine And Mill, Beaverhead County, Montana, Tyler Kamp Apr 2022

Surface Water/Groundwater Interactions And Hydrogeochemical Characterization Of The Elkhorn Mine And Mill, Beaverhead County, Montana, Tyler Kamp

Graduate Theses & Non-Theses

The formation of acid mine drainage (AMD) and the contaminants associated with it have been described by some as the largest environmental problem facing the U.S. mining industry. Heavy metals associated with the drainage, such as copper, cadmium, and zinc affect the water quality of streams and can cause acute or chronic toxicity to invertebrates and fish (Martin, 1992& Padrillah et al., 2018). Elkhorn Creek in the Pioneer Mountains of southwest Montana is one of these impacted creeks. The historic Elkhorn Mine and Mill complex has historically attributed to the creek’s contamination and has undergone remediation. However, the problem has …


The Oldest Mineralized Bryozoan? A Possible Palaeostomate In The Lower Cambrian Of Nevada, Usa, Sara B. Pruss, Lexie Leeser, Emily F. Smith, Andrey Yu Zhuravlev, Paul D. Taylor Apr 2022

The Oldest Mineralized Bryozoan? A Possible Palaeostomate In The Lower Cambrian Of Nevada, Usa, Sara B. Pruss, Lexie Leeser, Emily F. Smith, Andrey Yu Zhuravlev, Paul D. Taylor

Geosciences: Faculty Publications

All skeletal marine invertebrate phyla appeared during the Cambrian explosion, except for Bryozoa with mineralized skeletons, which first appear in the Early Ordovician. However, the skeletal diversity of Early Ordovician bryozoans suggests a preceding interval of diversification. We report a possible earliest occurrence of palaeostomate bryozoans in limestones of the Cambrian Age 4 Harkless Formation, western United States. Following recent interpretations of the early Cambrian Protomelission as a soft-bodied bryozoan, our findings add to the evidence of early Cambrian roots for the Bryozoa. The Harkless fossils resemble some esthonioporate and cystoporate bryozoans, showing a radiating pattern of densely packed tubes …


Groundwater Modeling Of The West Plains, Wa, Erin L. Toulou, Chad Pritchard Phd, Lauren Stachowiak Phd Apr 2022

Groundwater Modeling Of The West Plains, Wa, Erin L. Toulou, Chad Pritchard Phd, Lauren Stachowiak Phd

2022 Symposium

Located in Eastern Washington in the West Plains Region sits a plateau of Columbia River Basalts between Deep Creek, Hangman Creek, and south of the Spokane River. Primarily in Airway Heights, the amount of drinking water as well as the quality of the water has affected residents in the area. The most recent issue is PFAS contamination, which is thought to negatively affect human health and is found in drinking water wells across the West Plains. We can interpret subsurface geology using new well logs from Fairchild Air Force Base and in the Palisades area. When using ArcGIS PRO, well …


Instructor Selection And Use Of Virtual Field Experiences In College Geoscience Course, Kristen Foley Apr 2022

Instructor Selection And Use Of Virtual Field Experiences In College Geoscience Course, Kristen Foley

Masters Theses

Virtual Field Experiences (VFEs) are a growing supplement and gateway to traditional fieldwork in the geosciences. With VFEs becoming more accepted for use in college geoscience courses, how instructors find and choose VFEs for their students is critical to creating greater accessibility and future resources. VFEs that are not easily accessed by instructors may go unused, and the effort put into making them would have been wasted. This phenomenological descriptive study utilized five focus groups of college geoscience instructors in the United States. Each 1-to-1.5-hour focus group session of 3-7 participants took place on video conferencing software, which was recorded …


Improving Asteroid Remote Sensing By Examining Past Martian Methods, James Dean King Apr 2022

Improving Asteroid Remote Sensing By Examining Past Martian Methods, James Dean King

Theses

Deep Space Remote Sensing is an ever-evolving field. The very first missions into deep space were explorations that utilized trial and error, as humanity faced a new frontier of unknowns. Over these 70 years of deep space exploration, much attention has been given to our three nearest celestial neighbors: the Moon, Venus, and Mars. Mars, in particular, has been the target of much observation and study due to it being a target for future colonization. Meanwhile, the areas beyond Mars have had comparatively less focus. Asteroids and objects beyond Mars offer many new horizons for humanity to study. By using …


Gps-Derived Interseismic Fault Locking Along The Jalisco–Colima Segment Of The Mexico Subduction Zone, Beatriz Cosenza-Muralles, Charles Demets, B. Márquez-Azúa, O. Sánchez, J. Stock, Enrique Cabral-Cano, Robert Mccaffrey Apr 2022

Gps-Derived Interseismic Fault Locking Along The Jalisco–Colima Segment Of The Mexico Subduction Zone, Beatriz Cosenza-Muralles, Charles Demets, B. Márquez-Azúa, O. Sánchez, J. Stock, Enrique Cabral-Cano, Robert Mccaffrey

Geology Faculty Publications and Presentations

Northeastward subduction of the oceanic Rivera and Cocos plates in western Mexico poses a poorly understood seismic hazard to the overlying areas of the North America plate. We estimate the magnitude and distribution of interseismic locking along the northern ∼500 km of the Mexico subduction zone, with a series of elastic half-space inversions that optimize the fits to the velocities of 57 GPS stations in western Mexico. All velocities were corrected for the co-seismic, afterslip and viscoelastic rebound effects of the 1995 Colima–Jalisco and 2003 Tecomán earthquakes. We explore the robustness of interseismic locking estimates to a variety of mantle …


An Examination Of The Impacts Of Beaver Dam Mimicry Structures On Groundwater Surface-Water Interactions In Lower Mountain Riparian Systems, Mercedes D. Salazar Apr 2022

An Examination Of The Impacts Of Beaver Dam Mimicry Structures On Groundwater Surface-Water Interactions In Lower Mountain Riparian Systems, Mercedes D. Salazar

Graduate Theses & Non-Theses

Beaver dam analogs (BDAs) are a low cost, low disturbance stream restoration technique that may improve surface-water/groundwater interactions and wetland connectivity. BDAs are intended to imitate the effects of natural beaver dams by slowing stream velocity, promoting infiltration, increasing dry-season streamflow, aggrading the streambed, and capturing organic matter and other nutrients. This study was conducted to evaluate the degree to which these objectives were being met at a study site on Perkins Gulch, southwest Montana, USA. The Perkins Gulch study area can be summarized by four gauging sites that separate three reaches along the creek. By detailing background processes and …


Syllabus Geo101, Yuri Gorokhovich Apr 2022

Syllabus Geo101, Yuri Gorokhovich

Open Educational Resources

Syllabus for courses Dynamic Earth (undergraduate course): GEO 101-81 and Earth Processes (graduate course): GEO 501-81. Open textbook used in both courses linked in the syllabus and available at the following link: https://pressbooks.cuny.edu/gorokhovich/


The Mineralogy And Geochemistry Of Illinois Basin Paleosols: Recognizing Detrital, Pedogenic, And Diagenetic Minerals, Julia A. Mcintosh Apr 2022

The Mineralogy And Geochemistry Of Illinois Basin Paleosols: Recognizing Detrital, Pedogenic, And Diagenetic Minerals, Julia A. Mcintosh

Earth Sciences Theses and Dissertations

The geochemical compositions of minerals in paleosols are assumed to be homogenous and attained through chemical weathering processes during episodes of pedogenesis in the geologic past. As such, the geochemical composition of minerals from paleosols may be used to reconstruct ancient climates and environments. One problem with this assumption is that paleosols were initially clastic sedimentary rocks or substrate prior to pedogenesis, thus it is likely that some portion of the paleosol is still composed of detrital minerals. Secondly, conditions may change in a sedimentary basin as the basin is buried and later uplifted, potentially triggering new mineralization or transformation …


Cosmogenic Ages Indicate No Mis 2 Refugia In The Alexander Archipelago, Alaska, Caleb K. Walcott, Jason P. Briner, James F. Baichtal, Alia J. Lesnek, Joseph M. Licciardi Apr 2022

Cosmogenic Ages Indicate No Mis 2 Refugia In The Alexander Archipelago, Alaska, Caleb K. Walcott, Jason P. Briner, James F. Baichtal, Alia J. Lesnek, Joseph M. Licciardi

Publications and Research

The late-Pleistocene history of the coastal Cordilleran Ice Sheet remains relatively unstudied compared to chronologies of the Laurentide Ice Sheet. Yet accurate reconstructions of Cordilleran Ice Sheet extent and the timing of ice retreat along the Pacific Coast are essential for paleoclimate modeling, assessing meltwater contribution to the North Pacific, and determining the availability of ice-free land along the coastal Cordilleran Ice Sheet margin for human migration from Beringia into the rest of the Americas. To improve the chronology of Cordilleran Ice Sheet history in the Alexander Archipelago, Alaska, we applied 10Be and 36Cl dating to boulders and glacially sculpted …


In Situ Recording Of Mars Soundscape, S. Maurice, B. Chide, N. Murdoch, R. D. Lorenz, D. Mimoun, R. C. Wiens, Arya Udry, The Supercam Team Apr 2022

In Situ Recording Of Mars Soundscape, S. Maurice, B. Chide, N. Murdoch, R. D. Lorenz, D. Mimoun, R. C. Wiens, Arya Udry, The Supercam Team

Geoscience Faculty Research

Before the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat1, (2) the speed of sound varies at the surface with frequency2,3 and (3) high-frequency waves are strongly attenuated with distance in CO2 (refs. 2,3,4). However, theoretical models were uncertain because of a lack of experimental data at low pressure and the difficulty to characterize turbulence or attenuation in a closed environment. Here, using Perseverance microphone recordings, we present the first characterization of the acoustic environment …


Quantifying The Controls Of Shear-Coupled P-Waves, Jackson Saftner Apr 2022

Quantifying The Controls Of Shear-Coupled P-Waves, Jackson Saftner

Theses and Dissertations

Shear-coupled P-waves have been shown to possess great utility in resolving crustal and upper mantle models, however these phases remain largely untapped due to their ephemeral nature. Shear-coupled P-waves are a type of seismic phase that undergo S-to-P conversion either at the free-surface or at the base of the crust. Under the proper conditions, it is possible for the converted crustal P phases to achieve total internal reflection, allowing these phases to remain large in amplitude and sample long segments of the crust. In this study, we use a combination of real-world observations collected from literature, and synthetic seismograms, to …


Experimental Insights Into The Origin Of Microcrystalline Calcites, Mohammed Hashim Apr 2022

Experimental Insights Into The Origin Of Microcrystalline Calcites, Mohammed Hashim

Dissertations

A significant proportion of modern marine calcium carbonate sediments is dominated by metastable aragonite and high Mg calcite that either dissolves or stabilizes to low-Mg-calcite (calcite) or dolomite during diagenesis. Sediment dissolution and stabilization have implications for the CaCO3 budget in the ocean and carbon burial rates. Yet, the diagenetic conditions that promote each process and their relative importance are poorly understood. Further, stabilization most commonly produces calcite microcrystals that exhibit various textures and host micropores. Despite their ubiquity in the rock record, the controls on microcrystal textures remain unclear. Here, laboratory experiments were used to investigate aragonite-to-calcite stabilization as …


Assessment Of The Impact Of Climate Change On Stream Flow: The Case Of Little Ruaha Catchment, Rufiji Basin, Tanzania, Joel Nobert Mar 2022

Assessment Of The Impact Of Climate Change On Stream Flow: The Case Of Little Ruaha Catchment, Rufiji Basin, Tanzania, Joel Nobert

Tanzania Journal of Science

Little Ruaha catchment has been recognized for its potential to support multi-projects including irrigated schemes, urban water supply and providing significant inflow to Mtera reservoir for hydropower generation and ultimately Julius Nyerere Hydropower Plant (JNHPP).  Despite the potential, the catchment has experienced declining flows in the recent years. This study assessed the likely changes in streamflow due to future climate change in the Little Ruaha catchment for the period 2025-2060. General Circulation Model (GCM) datasets from ACCESS1.0, CNRM-CM5 and BCC-CSM1 models and RCP4.5 and RCP8.5 greenhouse gas concentration scenarios were selected as the representative scenarios. Impact of climate change on …


Geology Online Lab Activities An Open Educational Resource For Community College Students And Instructors, Rondi Davies Mar 2022

Geology Online Lab Activities An Open Educational Resource For Community College Students And Instructors, Rondi Davies

Open Educational Resources

The online geology lab for community college students was developed by Dr. Rondi Davies, a faculty member at Queensborough Community College, City University New York, during two years of forced online synchronous learning brought on by the COVID-19 pandemic. This open educational resource collects many of Dr. Davies’ favorite open-access materials and supplements them with her own work within a single, cohesive laboratory manual intended for two-year, non-major college students from the New York area.

Dr. Davies wanted to develop labs that were fun, engaging, and that excited students about the subject, were relevant to their lives, helped them to …


Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist Mar 2022

Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, supports a popular fishery for Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and Yellowstone Cutthroat Trout × Rainbow Trout O. mykiss hybrids. A majority of the adult population of fish in Henrys Lake are of hatchery origin that were stocked as fingerlings. The fishery is closed to angling during the late winter and spring months, but fisheries managers are considering opening the fishery year-round with catch-and-release- only regulations or with a two-fish bag limit during the extended season. However, there is concern that the proposed management actions may negatively affect the current fishery. Therefore, we developed an integrated …


Rose Valley Rocks!: From Plate Tectonics To Architecture Of Place, Walter Cressler Mar 2022

Rose Valley Rocks!: From Plate Tectonics To Architecture Of Place, Walter Cressler

University Libraries Faculty Publications

No abstract provided.


Characterizing Explosive Volcanic Eruptions Using Tephra Fall Deposit Data, Robert Constantinescu Mar 2022

Characterizing Explosive Volcanic Eruptions Using Tephra Fall Deposit Data, Robert Constantinescu

USF Tampa Graduate Theses and Dissertations

This dissertation addresses the estimation of the magnitudes and intensities of explosive volcanic eruptions using tephra fall deposits and numerical modeling. Tephra fall deposits retain information about eruption dynamics. Volcanologists sample tephra fall deposits and measure the thickness, extent and grain size distribution to estimate the erupted volume and plume height of explosive eruptions. These terms are known as eruption source parameters. These parameters are used to classify the intensity and magnitude of the eruption on a scale such as the Volcanic Explosivity Index (VEI). Accurate estimation of the intensity and magnitude of explosive eruptions is a crucial factor in …


Serving Beijing 2022 Olympic Winter Games And Developing Ice And Snow Industry: Application And Extension Of Cryospheric Science, Dahe Qin, Cunde Xiao, Minghu Ding, Feiteng Wang, Zhiqiang Zhu, Shuiqing Yin, Jiawen Ren Mar 2022

Serving Beijing 2022 Olympic Winter Games And Developing Ice And Snow Industry: Application And Extension Of Cryospheric Science, Dahe Qin, Cunde Xiao, Minghu Ding, Feiteng Wang, Zhiqiang Zhu, Shuiqing Yin, Jiawen Ren

Bulletin of Chinese Academy of Sciences (Chinese Version)

Cryospheric Science, as an emerging interdisciplinary research field combining natural science and humanity, aims to understand nature's law, serve human society and promote sustainable development. In recent years, by deepening the understanding of the cryosphere elements and the whole sphere, and by expanding the application research of cryospheric science, the Chinese community of cryospheric science has developed by leaps and bounds and realized the crossover from the traditional basic research to serving the major national needs, which marks the increasing maturity of the discipline. The Beijing 2022 Olympic Winter Games is a major landmark event at an important historical time …


Potassic Volcanism Induced By Mantle Upwelling Through A Slab Window: Evidence From Shear Wave Splitting Analyses In Central Java, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Jiabiao Li Mar 2022

Potassic Volcanism Induced By Mantle Upwelling Through A Slab Window: Evidence From Shear Wave Splitting Analyses In Central Java, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Jiabiao Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To delineate the mantle flow fields in the vicinity of a previously proposed slab window and the possible roles that they may play in the formation of potassic volcanism in Central Java, we conduct shear wave splitting analyses using both local S and teleseismic XKS waves (including SKS, SKKS, and PKS) recorded by 121 onshore stations and two ocean bottom seismometers (OBSs). The XKS fast orientations from the OBSs are trench normal and in accord with previous subslab anisotropy measurements. In the eastern part of Central Java, the XKS and local S fast orientations from the onshore stations are mostly …


Continental Break-Up Under A Convergent Setting: Insights From P Wave Radial Anisotropy Tomography Of The Woodlark Rift In Papua New Guinea, Youqiang Yu, Frederik Tilmann, Dapeng Zhao, Stephen S. Gao, Kelly H. Liu Mar 2022

Continental Break-Up Under A Convergent Setting: Insights From P Wave Radial Anisotropy Tomography Of The Woodlark Rift In Papua New Guinea, Youqiang Yu, Frederik Tilmann, Dapeng Zhao, Stephen S. Gao, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To explore the dynamic mechanism of continental rifting within a convergent setting, we determine the first P wave radial anisotropic tomography beneath the Woodlark rift in southeastern Papua New Guinea, which develops within the obliquely colliding zone between the Australian and southwest Pacific plates. The rift zone is depicted as localized low-velocity anomalies with positive radial anisotropy, which rules out a dominant role of active mantle upwelling in promoting the rift development and favors passive rifting with decompression melting as main processes. Downwelling slab relics in the upper mantle bounding the rift zone are revealed based on observed high-velocity anomalies …


Arsenic In Groundwater Sources From Selected Communities Surrounding Taal Volcano, Philippines: An Exploratory Study, Geminn Louis C. Apostol, Sary Valenzuela, Xerxes Seposo Mar 2022

Arsenic In Groundwater Sources From Selected Communities Surrounding Taal Volcano, Philippines: An Exploratory Study, Geminn Louis C. Apostol, Sary Valenzuela, Xerxes Seposo

Ateneo School of Medicine and Public Health Publications

Arsenic (As) is a highly toxic, carcinogenic trace metal that can potentially contaminate groundwater sources in volcanic regions. This study provides the first comparative documentation of As concentrations in groundwater in a volcano-sedimentary region in the Philippines. Matched, repeated As measurements and physico-chemical analyses were performed in 26 individual wells from 11 municipalities and city in Batangas province from July 2020 to November 2021. Using the electrothermal atomic absorption spectrometric method, analysis of the wells revealed that in 2020, 23 out of 26 (88.46%) had As levels above the WHO limit of >10 ppb while 20 out of 26 wells …