Assessing Land Deformation And Sea Encroachment In The Nile Delta: A Radar Interferometric And Modeling Approach,
2018
Western Michigan University
Assessing Land Deformation And Sea Encroachment In The Nile Delta: A Radar Interferometric And Modeling Approach, Esayas Gebrekidan Gebremichael
Dissertations
Many of the deltas of the world are experiencing land deformation, subsidence or uplift of landmass, due to natural or anthropogenic causes, or a combination of both processes and causes. These deltaic settings are densely populated and border some of our world’s largest water bodies (oceans and seas). The land deformation, especially the subsidence component, when combined with the climate change-induced sea level rise, coastal erosion, and other anthropogenic drivers, will undoubtedly impact the population and economy of coastal areas of deltas. For the Nile Delta of Egypt, the land deformation processes and the factors that control the deformation processes …
Subsurface Analysis Of Mississippian Tripolitic Chert In Northwest Arkansas,
2018
University of Arkansas, Fayetteville
Subsurface Analysis Of Mississippian Tripolitic Chert In Northwest Arkansas, Thomas Jason Liner
Graduate Theses and Dissertations
Over the past 70 years the Mississippian strata of Northwest Arkansas have been studied in great detail. The study area is located on the escarpment between the Boston Mountains Plateau and the Springfield Plateau where a surface occurrence of Mississippian age rock allows for access to outcrops in close proximity to gas wells that encounter subsurface Mississippian strata. Many outcrops found in Northwest Arkansas expose Lower Mississippian (Kinderhookian-Osagean) strata that represent a full third order transgressive/regressive sequence that is unconformity bounded. These Mississippian outcrops are commonly treated as surface analogs to the Mississippi Lime Play in North Central Oklahoma. This …
Speleogenesis In Turbulent Flow,
2018
University of Arkansas, Fayetteville
Speleogenesis In Turbulent Flow, Max P. Cooper
Graduate Theses and Dissertations
Existing models of speleogenesis neglect the shape of cross-sections, which can hold information related to climate, tectonics, and sediment supply in their widths. The first study of this dissertation simulates cross-sections of phreatic tubes, vadose canyons, and paragenetic galleries using a method developed for bedrock channels. Successful simulation of these cross-sections depends on erosion scaling with shear stress, in conflict with speleogenesis theory. Scaling of equilibrium width in paragenetic galleries was explored through analytical derivation and simulations, showing that width scales positively with discharge to the 1/2 power, and negatively with a weak power of sediment supply. Negative scaling of …
Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa,
2018
University of Arkansas, Fayetteville
Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa, Ashlon Elizabeth Leonard
Graduate Theses and Dissertations
Margaret White Springs (MWS) is one of the largest springs in the middle section of the Buffalo National River (BNR) and contributes several tens of cubic feet per second of flow to river discharge on average, yet the source of the water has not been fully studied or documented. The spring is located approximately 4 miles downstream from Robertson Hole, a losing reach of the river. At Robertson Hole the river loses a significant amount of flow to groundwater, which during the dry season (summer) can be as much as 100%. Flow in the main channel is re-established at MWS; …
Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic,
2018
Utrecht University
Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté
Science and Technology Department Faculty Journal Articles
Past changes in the atmospheric concentration of carbon dioxide (PCO2) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past PCO2 remains a prevalent challenge in paleoclimate studies. The current long-term PCO2reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we …
Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides,
2018
School of Ocean Science and Engineering, University of Southern Mississippi Stennis Space Center, MS
Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides, Christopher T. Hayes, Erin E. Black, Robert F. Anderson, Mark Baskaran, Ken O. Buesseler, Matthew A. Charette, Hai Cheng, J. Kirk Cochran, R. Lawrence Edwards, Patrick Fitzgerald, Phoebe J. Lam, Yanbin Lu, Stephanie O. Morris, Daniel C. Ohnemus, Frank J. Pavia, Gillian Stewart, Yi Tang
Environmental Science and Geology Faculty Research Publications
Sinking particles strongly regulate the distribution of reactive chemical substances in the ocean, including particulate organic carbon and other elements (e.g., P, Cd, Mn, Cu, Co, Fe, Al, and 232Th). Yet, the sinking fluxes of trace elements have not been well described in the global ocean. The U.S. GEOTRACES campaign in the North Atlantic (GA03) offers the first data set in which the sinking flux of carbon and trace elements can be derived using four different radionuclide pairs (238U:234Th ;210Pb:210Po; 228Ra:228Th; and 234U:230Th) at stations co-located with sediment trap fluxes for comparison. Particulate organic carbon, particulate P, and particulate Cd …
The Utility Of The Conductivity Mass-Balance Method For Base Flow Separation In Rivers And Streams,
2018
University of South Florida
The Utility Of The Conductivity Mass-Balance Method For Base Flow Separation In Rivers And Streams, Darline Alegria Lott
USF Tampa Graduate Theses and Dissertations
Freshwater for ecosystems, drinking water, and water for various businesses are important resources and those resources are rapidly diminishing globally due to drought and overuse. In order to manage the availability of water for all concerned, good estimates of base flow (groundwater) is required. Base flow, a component of streamflow, is deduced by separating a stream hydrograph into two components, base flow and runoff. There are several techniques used to perform base flow separation; however two techniques are used in this study, chemical mass-balance and analytical methods. This dissertation explains how an analytical technique was derived from a mass-balance method, …
Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa,
2018
East Central University
Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa, Kevin W. Blackwood, Lainee A. Sanders, Stacy I. Gantt-Blackwood
International Journal of Speleology
The Upper Geyser Basin in Yellowstone National Park occurs over a siliceous hydrothermal terrane containing numerous hot springs and geysers. The pool and vent-conduit geometries of these hydrothermal features share a resemblance to conventional karst features known from other rock types, suggesting karst processes could be responsible for their origin and/or evolution. Hypogene speleogenesis is a cave-forming process in which the formation of caves is decoupled from and occurs independently of surface recharge. The geologic setting for hypogene speleogenesis typically occurs at the distal end of regional groundwater systems wherein the hydrogeology is manifested by ascending fluids and/or by geochemical …
Mantle-To-Surface Neotectonic Connections In The San Juan Mountains Documented By 3he/4he, Co2 Flux Meaurements, And Hydrochemical Analysis Of The Geothermal System Near Rico, Colorado,
2018
University of New Mexico - Main Campus
Mantle-To-Surface Neotectonic Connections In The San Juan Mountains Documented By 3he/4he, Co2 Flux Meaurements, And Hydrochemical Analysis Of The Geothermal System Near Rico, Colorado, Benjamin D. Holt
Earth and Planetary Sciences ETDs
This project investigates the controls on geothermal fluids and their conduit systems which may account for high mantle helium components of geothermal fluids in intracratonic continental regions. The field laboratory is the western San Juan Mountains of southwestern Colorado where the structural setting and hydrochemistry of carbonic springs suggest potential connections among surface hot springs, fault networks, CO2 degassing, significant geothermal potential, young volcanic and plutonic rocks (< 7 Ma), and low-velocity upper mantle. The Rico Hot Springs have the highest mantle volatile component of any spring in Colorado with air-corrected values of 3He/4He = 5.88 RA indicating 73% mantle helium component. This near-MORB mantle helium value at Rico indicates that volatiles degassing from the mantle must be rapidly transmitted into the groundwater system along deep-seated faults such that accumulation of 4He from radiogenic crust has not swamped mantle-derived primordial 3He. Geologic features that are important for volatile transport and spring chemistry controls include a complex conduit system and fault network involving the Precambrian-cored Rico Dome, ~4 Ma intrusive rocks at Calico Peak and Priest Gulch, and a low-velocity upper mantle. Therefore, Rico and the surrounding region is a natural laboratory for studying geothermal fluid and mantle volatile pathways. Additional noble gas analyses and hydrochemistry data were gathered from regional springs and modeled via chemical geothermometers. New noble gas measurements from this study, paired with literature values, reveal highest air corrected 3He/4He at Rico (4.09-5.88 RA), Dunton (3.11-4.54 RA), Geyser Warm Spring (3.39 RA), and Paradise Warm Spring (2.72 RA). Water volume is dominated by meteoric fluids as shown by stable isotope data but hydrochemistry indicates high TDS, high CO2, and high He come from a geothermal fluid endmember. Variable mixing and water-rock interactions are processes that can explain chemistry variations between spatially proximal springs. CO2 flux measurements (up to 36.2 g/m2/hr) vary across structural features and demonstrate that the faults act as pathways for CO2 flux suggesting ongoing degassing. Overall, we find that local high mantle helium signature is localized directly above regions of lowest upper mantle velocity in the San Juan mantle anomaly and is derived from neotectonic mantle melts in those regions.
Martian Magmatism From Plume Metasomatized Mantle,
2018
University of California San Diego
Martian Magmatism From Plume Metasomatized Mantle, James M. D. Day, Kimberly T. Tait, Arya Udry, Frédéric Moynier, Yang Liu, Clive R. Neal
Geoscience Faculty Research
Direct analysis of the composition of Mars is possible through delivery of meteorites to Earth. Martian meteorites include ∼165 to 2400 Ma shergottites, originating from depleted to enriched mantle sources, and ∼1340 Ma nakhlites and chassignites, formed by low degree partial melting of a depleted mantle source. To date, no unified model has been proposed to explain the petrogenesis of these distinct rock types, despite their importance for understanding the formation and evolution of Mars. Here we report a coherent geochemical dataset for shergottites, nakhlites and chassignites revealing fundamental differences in sources. Shergottites have lower Nb/Y at a given Zr/Y …
Post-Impact Light Vapor Incorporation During Lunar Formation Based On Triple Oxygen Isotopes,
2018
University of New Mexico - Main Campus
Post-Impact Light Vapor Incorporation During Lunar Formation Based On Triple Oxygen Isotopes, Erick J. Cano
Earth and Planetary Sciences ETDs
Initial triple oxygen isotope analyses of lunar samples showed them to be indistinguishable from Earth, which led to numerous papers aimed at explaining the similarities. Recent high-precision analyses suggested either a subtle enrichment in Δ'17O or virtually no difference between the Earth and Moon. Herein we expand on previous studies by correlating the triple oxygen isotope measurements with different lunar lithologies. We show that these data can be explained by mixing between a light vapor phase, generated during the Giant Impact, and the residual material from the proto-lunar impactor ‘Theia’. There is a general decrease in Δ'17 …
Sedimentology And Stratigraphy Of Core Stl14: An Early Pleistocene-To-Present Paleoclimate Archive From Stoneman Lake, Arizona,
2018
University of New Mexico
Sedimentology And Stratigraphy Of Core Stl14: An Early Pleistocene-To-Present Paleoclimate Archive From Stoneman Lake, Arizona, Spencer Staley
Earth and Planetary Sciences ETDs
An 80 m lacustrine sediment core (STL14) from Stoneman Lake, Coconino County, Arizona, contains a sedimentary sequence of at least 1.5 million years, chronicling the complete history of basin infill and recording an extensive and high-resolution archive of climatic and hydrologic fluctuations. Lake levels in this small, internally-drained catchment are sensitive to changes in regional hydrologic balance. Consistent groundwater inflow, even during regionally dry episodes in the lake’s history, has prevented complete desiccation of the lake and sustained continuous lacustrine deposition except for one soil horizon. Multiproxy analysis of sedimentological indicators including lithofacies, color, wet bulk density, magnetic susceptibility, preliminary …
Radionuclides In Rainwater And Their Impact On Background Radiation,
2018
University of New Mexico - Main Campus
Radionuclides In Rainwater And Their Impact On Background Radiation, Damien M. Milazzo
Earth and Planetary Sciences ETDs
Radioactive waste has accrued throughout the continental United States and in the Oceans surrounding the country. Significant quantities of the waste are poorly documented regarding their location and the radioisotopes contained in the waste. Locating the waste is not an easy matter, as its locations are not well documented, and its method of disposal may be covered with plants, soils, and sediments. A common tool used to locate the waste is a gamma spectrometer, which measure the gamma emissions spectrum of radionuclides. The effectiveness of this tool when utilized to locate gamma emitting waste may be reduced due to the …
The Fate Of Sulfur During Melting And Crystallization: Implications For Sulfur Transfer From Mantle To The Crust-Atmosphere System,
2018
CUNY Queens College
The Fate Of Sulfur During Melting And Crystallization: Implications For Sulfur Transfer From Mantle To The Crust-Atmosphere System, Shuo Ding
Sustainability Seminar Series
Sulfur (S) is one of the most abundant volatiles; one that has a fundamental impact on various magmatic processes, from the mantle to the Earth’s surface. Ocean island basalts (OIB) are one of the critical probes for understanding the chemical, lithological and thermal variations in the Earth’s mantle. Therefore, S abundances of primary OIB that sample peridotite partial melts, as well as deeply recycled components, can provide a better understanding of the long-term S cycle on Earth. In this study, we developed a model to describe the behavior of sulfide and copper (Cu) during decompression melting of the mantle by …
Natural Trace Element Salinization Of The Jemez River, New Mexico By Geothermal Springs And Major Tributaries,
2018
University of New Mexico - Main Campus
Natural Trace Element Salinization Of The Jemez River, New Mexico By Geothermal Springs And Major Tributaries, Jon K. Golla, Laura J. Crossey, Abdul-Mehdi S. Ali, Karl E. Karlstrom
Shared Knowledge Conference
The Jemez River (JR), a tributary of the Rio Grande, is in north-central New Mexico within the Jemez Mountains, which houses the active, high-temperature (≤ 300 oC), liquid-dominated Valles Caldera geothermal system (VC). This work focuses on the northern portion of the JR, spanning a reach from the East Fork JR to the town of San Ysidro. Previous decadal work during low-flow or baseflow conditions (~10-20 cfs) has identified and characterized significant major-solute contributions from two outflow expressions of the VC, Soda Dam Springs and Jemez Hot Springs, and two major tributaries, Rio San Antonio and Rio Guadalupe. There is …
Microbial Diversity In Urban Environments: Concern For Antibiotic Resistance,
2018
Johns Hopkins University
Microbial Diversity In Urban Environments: Concern For Antibiotic Resistance, Ality Aghedo, Mangala Tawde, Nazrul I. Khandaker
Publications and Research
We are almost oblivious to the presence of microorganisms in our daily lives, but they exist and come into contact with us all the time. While some bacteria are harmless, and even beneficial, other bacteria can cause infections. A common treatment to bacterial infections is antibiotics and the success of an antibiotic depends on the resistance of the bacteria to the antibiotic. We conducted experiments to identify the types of bacteria that can be found on surfaces or within soil environments that come into contact with a vast number of people on a daily basis and how this can affect …
An Overview Of Smartwater Management System: Strategic Potential In Bangladesh,
2018
University of Dhaka
An Overview Of Smartwater Management System: Strategic Potential In Bangladesh, Muhammad Qumrul Hassan, Mir F. Karim, Nazrul I. Khandaker, Jowaher Raza
Publications and Research
Water loss management is becoming an increasingly important as supplies are stressed by population growth or water scarcity. A SmartWater system ensures optimum consumption and prediction of future water use. Bangladesh is one of the most vulnerable countries due to global climate change considering its rapid urbanization, inequitable land use, low income and greater reliance on climate sensitive sectors, particularly agriculture. Agricultural lands used for cropping and livestock rearing are more susceptible to degradation than non-agricultural lands. Most farmers irrigate through flooding, losing up to 75% of water to evaporation and creating a substantial drawdown of much needed water for …
Water Flow Net Characterization By Using A Tank Model: Preliminary Outcome,
2018
CUNY York College
Water Flow Net Characterization By Using A Tank Model: Preliminary Outcome, Jasmin Budhan, Nazrul I. Khandaker, Stanley Schleifer
Publications and Research
A model study was conducted to observe and characterize the flow of water through sandy soil. One of the most relevant tools used for characterizing groundwater flow is the flow net. Assuming that water is incompressible and there is zero volume change in the soil mass, it is known that the total rate of inflow is to equal the total rate of outflow. Thus, following the principle of flow continuity, we use the Laplace equation of continuity, to observe the concept of the flow net. Computing the flow through a miniature channel, we observed the total head difference from the …
Nasa Maa (Murep Aerospace Academy) Stem Project At York College: Ensuring Future Stem Pipeline,
2018
CUNY York College
Nasa Maa (Murep Aerospace Academy) Stem Project At York College: Ensuring Future Stem Pipeline, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Brandon Dhanraj, Zachary A. Sanichar, Mildred M. Selby, Chabenauth Ramnauth, Theresa Deepan, Yougeeta Singh, Krishna Mahabir, Sashi Singh, Omadevi Singh
Publications and Research
Our ongoing K1-12 NASA-supported STEM activities has served over 5000 children since 2015, largely from groups that are undeserved and underrepresented in the sciences. These STEM activities have been successfully delivered for several years and include earth science, meteorite geology, rocketry, aerodynamics, star gazing, EV3 Mindstorm robotics, basic coding exercises, wind tunnel, 3D-printing, etc., conducted largely through our present MAA (MUREP Aerospace Academy) Project. Corporate funding from the Con Edison and National Grid ensures additional STEM dissemination to the students during the summer operation. Significant positive component of the MAA program is the availability and willingness of the former student …
The Status Of Engineering Geology: Constraints On Infrastructure Development In Bangladesh,
2018
Geotesting Express Inc.
The Status Of Engineering Geology: Constraints On Infrastructure Development In Bangladesh, Mir Fazlul Karim, Muhammad Qumrul Hassan, Nazrul I. Khandaker, Masud Ahmed, Belal Ahmed Sayeed
Publications and Research
In recent years, megacity Dhaka is known to have one of the fastest urban population growths in Bangladesh. The population in Dhaka and other megacities has increased from 7 to 50 million during the last four decades. The rapid rate of urban population growth, along with the extreme paucity of real-estate for new infrastructure development or upgrading existing facilities, is already exacerbating the situation for the city planners and exerting tremendous pressure to come-up with viable solutions. Although practice of engineering geology, geotechnical exploration, and testing exists in Bangladesh; the system has still yet to adopt controlled quality standards with …
