Repetitive Sampling And Control Threshold Improve 16s Rrna Gene Sequencing Results From Produced Waters Associated With Hydraulically Fractured Shale,
2020
U.S. Geological Survey, Sacramento, CA
Repetitive Sampling And Control Threshold Improve 16s Rrna Gene Sequencing Results From Produced Waters Associated With Hydraulically Fractured Shale, Jenna L. Shelton, Elliott P. Barnhart, Leslie Ruppert, Aaron M. Jubb, Madalyn S. Blondes, Christina A. Devera
United States Geological Survey: Staff Publications
Sequencing microbial DNA from deep subsurface environments is complicated by a number of issues ranging from contamination to non-reproducible results. Many samples obtained from these environments – which are of great interest due to the potential to stimulate microbial methane generation – contain low biomass. Therefore, samples from these environments are difficult to study as sequencing results can be easily impacted by contamination. In this case, the low amount of sample biomass may be effectively swamped by the contaminating DNA and generate misleading results. Additionally, performing field work in these environments can be difficult, as researchers generally have limited access …
Integrated Borehole, Radar, And Seismic Velocity Analysis Reveals Dynamic Spatial Variations Within A Firn Aquifer In Southeast Greenland,
2020
School of Earth and Environment, University of Leeds, Leeds, UK
Integrated Borehole, Radar, And Seismic Velocity Analysis Reveals Dynamic Spatial Variations Within A Firn Aquifer In Southeast Greenland, S. F. Killingbeck, N. C. Schmerr, L. N. Montgomery, A. D. Booth, P. W. Livermore, J. Guandique, O. L. Miller, S. Burdick, R. R. Forster, L. S. Koenig, A. Legchenko, S. R. M. Ligtenberg, C. Miège, D. K. Solomon, L. J. West
Environmental Science and Geology Faculty Research Publications
Perennial water storage in firn aquifers has been observed within the lower percolation zone of the southeast Greenland ice sheet. Spatially distributed seismic and radar observations, made ~50 km upstream of the Helheim Glacier terminus, reveal spatial variations of seismic velocity within a firn aquifer. From 1.65 to 1.8 km elevation, shear-wave velocity (Vs) is 1,290 ± 180 m/s in the unsaturated firn, decreasing below the water table (~15 m depth) to 1,130 ± 250 m/s. Below 1.65 km elevation, Vs in the saturated firn is 1,270 ± 220 m/s. The compressional-to-shear velocity ratio decreases in the downstream saturated zone, …
Geology, Geochemistry And Petrotectonic Setting Of Idanre Granite Complex, Southwestern Nigeria,
2020
Universiti Malaya
Geology, Geochemistry And Petrotectonic Setting Of Idanre Granite Complex, Southwestern Nigeria, Akinola Oluwatoyin Olagoke
Student Works (2020-2029)
During Neoproterozoic, Nigeria like many other Pan-African countries witnessed extensive magmatic activities which resulted in emplacement of granite popularly referred to as Older Granite in Nigeria. The study area is characterized by a large population of this rock type than any other part of Nigeria, so these rocks are investigated in this research. Idanre is underlain by migmatite-gneiss, charnockite and granite. Migmatite form the country rock and are low-lying, charnockite was surrounded by granite, while the granite forms large inselbergs. Three textural types of granite occur in the area, they are coarse-grained granite (undifferentiated) (OGu), porphyritic granite (OGp) and the …
Direct P-Wave Anisotropy Measurements At Homestake Mine: Implications For Wave Propagation In Continental Crust,
2020
Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN
Direct P-Wave Anisotropy Measurements At Homestake Mine: Implications For Wave Propagation In Continental Crust, James Atterholt, Sarah J. Brownlee, Gary L. Pavlis
Environmental Science and Geology Faculty Research Publications
We measured anisotropic seismic properties of schists of the Homestake Formation located at a depth of 1478 m in the Sanford Underground Research Facility (SURF) in the Black Hills of South Dakota, USA. We deployed a 24-element linear array of three-component geophones in an area in the Homestake Mine called 19-ledge. An airless jackhammer source was used to shoot two profiles: (1) a walkaway survey to appraise any distance dependence and (2) a fan shot profile to measure variations with azimuth. Slowness estimates from the fan shot profile show a statistically significant deviation with azimuth with the expected 180° variation …
Strategies For Preparing And Delivering An Effective Online Presentation,
2020
DePauw University
Strategies For Preparing And Delivering An Effective Online Presentation, Kenneth L. Brown, Claire L. Mcleod
Geology and Environmental Geoscience Faculty Publications
No abstract provided.
Global Patterns Of Recent Mass Movement On Asteroid (101955) Bennu,
2020
Rowan University
Global Patterns Of Recent Mass Movement On Asteroid (101955) Bennu, E. R. Jawin, K. J. Walsh, O. S. Barnouin, T. J. Mccoy, R.-L. Ballouz, D. N. Dellagiustina, Harold Connolly Jr.
School of Earth & Environment Departmental Research
The exploration of near‐Earth asteroids has revealed dynamic surfaces characterized by mobile, unconsolidated material that responds to local geophysical gradients, resulting in distinct morphologies and boulder distributions. The OSIRIS‐REx (Origins, Spectral Interpretation, Resource Identification, and Security‐Regolith Explorer) mission confirmed that asteroid (101955) Bennu is a rubble pile with an unconsolidated surface dominated by boulders. In this work, we documented morphologies indicative of mass movement on Bennu and assessed the relationship to slope and other geologic features on the surface. We found globally distributed morphologic evidence of mass movement on Bennu up to ~70° latitude and on spatial scales ranging from …
Geochemical Characterization Of Base Metals In Stream Water And Sediments In The Caddo Lake Watershed, Cass, Harrison, And Marion Counties, Texas,
2020
Stephen F Austin State University
Geochemical Characterization Of Base Metals In Stream Water And Sediments In The Caddo Lake Watershed, Cass, Harrison, And Marion Counties, Texas, Melinda S. Faulkner, Melanie L. Ertons, Joseph D. Watkins
Faculty Publications
The Caddo Lake watershed is located in northeastern Texas and encompasses much of Cass, Harrison, and Marion counties. The watershed is drained by major streams and tributaries flowing in an easterly direction over Eocene-aged rocks and sediments of the Wilcox and Claiborne groups, and empty into the western arm of Caddo Lake. Since 1995, Caddo Lake and some of its tributaries have been included on the State of Texas Clean Water Act 303(d) list by the Texas Commission on Environmental Quality (TCEQ) for impairment due to mercury content in edible tissue, depressed dissolved oxygen, base metal concentrations, and low pH …
Rainfall Triggers More Deep-Seated Landslides Than Cascadia Earthquakes In The Oregon Coast Range, Usa,
2020
University of Washington-Seattle
Rainfall Triggers More Deep-Seated Landslides Than Cascadia Earthquakes In The Oregon Coast Range, Usa, Sean R. Lahusen, Alison R. Duvall, Adam M. Booth, A. Grant, Ben A. Mishkin, David R. Montgomery, Will Struble, Joshua J. Roering, J. Wartman
Geology Faculty Publications and Presentations
The coastal Pacific Northwest USA hosts thousands of deep-seated landslides. Historic landslides have primarily been triggered by rainfall, but the region is also prone to large earthquakes on the 1100-km-long Cascadia Subduction Zone megathrust. Little is known about the number of landslides triggered by these earthquakes because the last magnitude 9 rupture occurred in 1700 CE. Here, we map 9938 deep-seated bedrock landslides in the Oregon Coast Range and use surface roughness dating to estimate that past earthquakes triggered fewer than half of the landslides in the past 1000 years. We find landslide frequency increases with mean annual precipitation but …
Future Availability Of Non-Renewable Metal Resources And The Influence Of Environmental, Social, And Governance Conflicts On Metal Production,
2020
University of Nevada, Las Vegas
Future Availability Of Non-Renewable Metal Resources And The Influence Of Environmental, Social, And Governance Conflicts On Metal Production, Simon Jowitt, Gavin M. Mudd, John F.H. Thompson
Geoscience Faculty Research
Metal mining provides the elements required for the provision of energy, communication, transport and more. The increasing uptake of green technology, such as electric vehicles and renewable energy, will also further increase metal demand. However, the production lifespan of an average mine is far shorter than the timescales of mineral deposit formation, suggesting that metal mining is unsustainable on human timescales. In addition, some research suggests that known primary metal supplies will be exhausted within about 50 years. Here we present an analysis of global metal reserves that suggests that primary metal supplies will not run out on this timescale. …
Slab Dehydration And Mantle Upwelling In The Vicinity Of The Sumatra Subduction Zone: Evidence From Receiver Function Imaging Of Mantle Transition Zone Discontinuities,
2020
Missouri University of Science and Technology
Slab Dehydration And Mantle Upwelling In The Vicinity Of The Sumatra Subduction Zone: Evidence From Receiver Function Imaging Of Mantle Transition Zone Discontinuities, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Weiwei Ding, Jiabiao Li
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
A total of 10,586 P-to-S radial receiver functions recorded by 64 broadband seismic stations were utilized to image the 410 and 660 km discontinuities (d410 and d660, respectively) bordering the mantle transition zone (MTZ) beneath the Sumatra Island, the Malay Peninsula, and the western margin of the South China Sea. The d410 and d660 were imaged by stacking receiver functions in successive circular bins with a radius of 1°, after moveout corrections based on the 1-D IASP91 Earth model. The resulting apparent depths of the discontinuities exhibit significant and spatially systematic variations. The apparent depths of the d410 and d660 …
Late-Holocene Shoreline Responses To Competing Shelf, Bay, And Beach Accommodation Spaces Under Conditions Of Relative Sea Level Change, And The Potential For Future Catastrophic Beach Retreat In The Columbia River Littoral Cell, Washington And Oregon, Usa,
2020
Portland State University
Late-Holocene Shoreline Responses To Competing Shelf, Bay, And Beach Accommodation Spaces Under Conditions Of Relative Sea Level Change, And The Potential For Future Catastrophic Beach Retreat In The Columbia River Littoral Cell, Washington And Oregon, Usa, Curt D. Peterson, Tamara C. Linde, Sandy Vanderburgh
Geology Faculty Publications and Presentations
The Columbia River Littoral Cell (CRLC) (160 km in length) provides opportunities to compare competing accommodation space relations under different conditions of relative sea level change. The CRLC system includes abundant littoral sand supply from the large Columbia River, late-Holocene prograded beach plains and barrier spits (0.5–5 km in width), two large marine-dominated estuaries (Willapa Bay and Grays Harbor), and a high-wave-energy inner-shelf. Littoral sand accumulation rates in prograded beach plains and barrier deposits are based on paleo-shoreline positions that are dated by great-earthquake catastrophic beach retreat scarps (n = 10) from 0.3 to 5.0 ka. The retreat scarp timelines …
Topography Of The 410 And 660 Km Discontinuities Beneath The Cenozoic Okavango Rift Zone And Adjacent Precambrian Provinces,
2020
Missouri University of Science and Technology
Topography Of The 410 And 660 Km Discontinuities Beneath The Cenozoic Okavango Rift Zone And Adjacent Precambrian Provinces, Youqiang Yu, Stephen S. Gao, Kelly H. Liu
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
By taking advantage of the recent availability of a broadband seismic data set from Networks NR and BX covering the entire country of Botswana, we conduct a systematic receiver function investigation of the topography of the 410 and 660 km discontinuities beneath the incipient Okavango rift zone (ORZ) in northern Botswana and its adjacent Archean-Proterozoic tectonic provinces in southern Africa. Similar to a previous mantle transition zone (MTZ) discontinuity study using data from a 1-D profile traversing the ORZ, a normal MTZ thickness is observed in most parts of the study area. This is inconsistent with the existence of widespread …
“Enriching Lives Within Sedimentary Geology”: Actionable Recommendations For Making Sepm A Diverse, Equitable And Inclusive Society For All Sedimentary Geologists,
2020
University of New Orleans
“Enriching Lives Within Sedimentary Geology”: Actionable Recommendations For Making Sepm A Diverse, Equitable And Inclusive Society For All Sedimentary Geologists, R.C. Mahon, A.M. Fernandes, A. Abeyta, R. Martindale, K.D Bergman, C. Jackson, Et Al
Earth and Environmental Sciences Faculty Publications
Innovative science benefits from diversity of thought and influence at all waypoints along the scientific journey, from early education to career-length contributions in research and mentorship. Scientific societies, like the Society for Sedimentary Geology (SEPM), steward their innovators and the direction of the science, thereby defining the societal impact and evolution of a discipline. They are uniquely positioned to promote the representation and success of all scientists, including those from minoritized populations, through proactive advocacy, and inclusive mentorship, awards, and leadership. We introspectively review available records of SEPM membership, leadership, awardees, and editorial boards to identify areas for growth and …
Seasonal Infilling And Sedimentary Characteristics In Sandy Versus Muddy Coastal Borrow Areas On The Louisiana Continental Shelf, Usa,
2020
Louisiana State University
Seasonal Infilling And Sedimentary Characteristics In Sandy Versus Muddy Coastal Borrow Areas On The Louisiana Continental Shelf, Usa, Matthew Barley
LSU Master's Theses
Offshore sand deposits on the Louisiana Continental Shelf, such as inner shelf shoals and buried paleo-river channels, can be excavated to restore beaches and barrier islands that are rapidly deteriorating due to subsidence, sea-level rise and deficits in coastal sediment supply. Presented here is grain size, x-radiograph, and Beryllium-7 (7Be) derived sedimentation rates from multicores (~ 50 cm depth) retrieved from borrow areas (BAs) in contrasting depositional settings, all of which have implications for management of water quality, seafloor sedimentology, and biogeochemistry in proximal areas. Multicores were retrieved in fall 2018 at Caminada BA — a sandy energetic …
Evaluating Airsoft Electric Guns For Control Of Invasive Brown Treesnakes,
2020
Maui Invasive Species Committee
Evaluating Airsoft Electric Guns For Control Of Invasive Brown Treesnakes, Adam J. Knox, Björn Lardner, Amy Yackel Adams, Robert N. Reed
United States Geological Survey: Staff Publications
Firearms are often used in lethal control of invasive vertebrates, but safety and regulatory aspects limit the circumstances under which they can be used. During August 2016 at the Brown Treesnake Project laboratory on Guam, we evaluated hobby‐grade Airsoft Electric Guns (AEGs; a lower powered, less‐hazardous, and less‐regulated alternative to firearms) for capture and control of small animals, with specific emphasis on invasive brown treesnakes (Boiga irregularis). Tests of AEGs differing in power with ammunition (plastic pellets) masses ranging from 0.20 to 0.39 g, fired at gelatin blocks from distances of 4, 8, and 12 m, showed that …
Distribution, Geochronology, And Petrogenesis Of The Picture Gorge Basalt With Special Focus On Petrological Relationships To The Main Columbia River Basalt Group,
2020
Portland State University
Distribution, Geochronology, And Petrogenesis Of The Picture Gorge Basalt With Special Focus On Petrological Relationships To The Main Columbia River Basalt Group, Emily Bogdan Cahoon
Dissertations and Theses
The Columbia River Basalt Group (CRBG) is the youngest and volumetrically smallest continental flood basalt exposed across the Pacific Northwest, USA. Similar to other large igneous provinces, the majority of material erupted during the initial 1 million years of activity, these lavas are subdivided into four main-phase units. The Picture Gorge Basalt (PGB) is the only main-phase unit of the CRBG whose age is not precisely known and understanding of PGB petrogenesis is largely based on a limited number of samples when compared with other main-phase units. It is suggested that a time gap of over 0.5 myr existed between …
Proceedings For Conservation Of Fragile Karst Resources,
2020
Western Kentucky University
Proceedings For Conservation Of Fragile Karst Resources, Crawford Hydrology Laboratory, The George Wright Society, Mammoth Cave National Park
Conservation of Fragile Karst Resources Proceedings
A Workshop on Sustainability and Community in support of UNESCO science programs August 18-20, 2020
Olivine,
2020
University of Alabama at Birmingham
Galena,
2020
University of Alabama at Birmingham
Hornblende,
2020
University of Alabama at Birmingham
