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Comparison Of Microbial Communities In The Sediments And Water Columns Of Frozen Cryoconite Holes In The Mcmurdo Dry Valleys, Antarctica, Pacifica Sommers, John L. Darcy, Dorota L. Porazinska, Eli M. S. Gendron, Andrew G. Fountain, Felix Jacob Zamora, Kim Vincent, Kaelin M. Cawley, Adam J. Solon, Lara Vimercati, Jenna Ryder, Steven K. Schmidt 2019 University of Colorado Boulder

Comparison Of Microbial Communities In The Sediments And Water Columns Of Frozen Cryoconite Holes In The Mcmurdo Dry Valleys, Antarctica, Pacifica Sommers, John L. Darcy, Dorota L. Porazinska, Eli M. S. Gendron, Andrew G. Fountain, Felix Jacob Zamora, Kim Vincent, Kaelin M. Cawley, Adam J. Solon, Lara Vimercati, Jenna Ryder, Steven K. Schmidt

Geology Faculty Publications and Presentations

Although cryoconite holes, sediment-filled melt holes on glacier surfaces, appear small and homogenous, their microbial inhabitants may be spatially partitioned. This partitioning could be particularly important for maintaining biodiversity in holes that remain isolated for many years, such as in Antarctica. We hypothesized that cryoconite holes with greater species richness and biomass should exhibit greater partitioning between the sediments and water, promoting greater biodiversity through spatial niche partitioning. We tested this hypothesis by sampling frozen cryoconite holes along a gradient of biomass and biodiversity in the Taylor Valley, Antarctica, where ice-lidded cryoconite holes are a ubiquitous feature of glaciers. We ...


Speleothem Paleoclimatology For The Caribbean, Central America, And North America, Jessica L. Oster, Sophie F. Warken, Natasha Sekhon, Monica M. Arienzo, Matthew Lachniet 2019 Vanderbilt University

Speleothem Paleoclimatology For The Caribbean, Central America, And North America, Jessica L. Oster, Sophie F. Warken, Natasha Sekhon, Monica M. Arienzo, Matthew Lachniet

Geoscience Faculty Publications

Speleothem oxygen isotope records from the Caribbean, Central, and North America reveal climatic controls that include orbital variation, deglacial forcing related to ocean circulation and ice sheet retreat, and the influence of local and remote sea surface temperature variations. Here, we review these records and the global climate teleconnections they suggest following the recent publication of the Speleothem Isotopes Synthesis and Analysis (SISAL) database. We find that low-latitude records generally reflect changes in precipitation, whereas higher latitude records are sensitive to temperature and moisture source variability. Tropical records suggest precipitation variability is forced by orbital precession and North Atlantic Ocean ...


Landslides Near Enguri Dam (Caucasus, Georgia) And Possible Seismotectonic Effects, Alessandro Tibaldi, Paolo Oppizzi, John S. Gierke, Thomas Oommen, Nino Tsereteli, Zurab Gogoladze 2019 Università degli Studi di Milano-Bicocca

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

Department of Geological and Mining Engineering and Sciences Publications

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


Assessment Of Post-Wildfire Debris Flow Occurrence Using Classifier Tree, Priscilla Addison, Thomas Oommen, Qiuying Sha 2019 Michigan Technological University

Assessment Of Post-Wildfire Debris Flow Occurrence Using Classifier Tree, Priscilla Addison, Thomas Oommen, Qiuying Sha

Department of Geological and Mining Engineering and Sciences Publications

Besides the dangers of an actively burning wildfire, a plethora of other hazardous consequences can occur afterwards. Debris flows are among the most hazardous of these, being known to cause fatalities and extensive damage to infrastructure. Although debris flows are not exclusive to fire affected areas, a wildfire can increase a location’s susceptibility by stripping its protective covers like vegetation and introducing destabilizing factors such as ash filling soil pores to increase runoff potential. Due to the associated dangers, researchers are developing statistical models to isolate susceptible locations. Existing models predominantly employ the logistic regression algorithm; however, previous studies ...


Using A Case Study Approach To Teach Invasive Species And Climate Change, Amanda Hoover, Bradley Blaha, Jacob Englin, Madhav P. Nepal, Larry B. Browning, Matt L. Miller, P. Troy White 2019 Lake Preston School District, Lake Preston, South Dakota

Using A Case Study Approach To Teach Invasive Species And Climate Change, Amanda Hoover, Bradley Blaha, Jacob Englin, Madhav P. Nepal, Larry B. Browning, Matt L. Miller, P. Troy White

iLEARN Teaching Resources

In this teaching module, students will explore emerald ash borer (EAB), its impacts on the ash trees, and how warming temperatures could affect EAB populations. The emerald ash borer is a green buprestid or jewel beetle native to north-eastern Asia that causes devastating disease in ash trees.


Comparing Dietary Differences Among The Hornless Artiodactyl Ruminants Hypertragulus, Hypisodus, And Leptomeryx From The Early Oligocene (Orellan) Brule Formation, Toadstool Geologic Park, Nebraska, Holly Chien Seyler 2019 University of Colorado at Boulder

Comparing Dietary Differences Among The Hornless Artiodactyl Ruminants Hypertragulus, Hypisodus, And Leptomeryx From The Early Oligocene (Orellan) Brule Formation, Toadstool Geologic Park, Nebraska, Holly Chien Seyler

Museum and Field Studies Graduate Theses & Dissertations

The Early Oligocene (Orellan) in the North American Western Interior is marked by a cooler and dryer climate than the late Eocene (Chadronian). New mammalian taxa appeared while other groups already present began to diversify. This study takes a closer look at the diversification of hornless ruminant artiodactyls present in the Latest Orellan Merycoidodon bullatus Interval Zone through an analysis of 70 specimens from three closely related species: Hypertragulus (27), Hypisodus (18), and Leptomeryx (25) from a single locality in Toadstool Geologic Park, Nebraska. Specifically, we took a closer look at the hypsodonty index, mesowear, and tooth volume, which have ...


A Geological History Of Clark County, Arkansas, Joe Jeffers 2019 Ouachita Baptist University

A Geological History Of Clark County, Arkansas, Joe Jeffers

Articles

The geological history of Clark County is described ranging from 500 million years ago to the present. One-third of present-day Clark County is in the Ouachita Mountains, two-thirds is in the Coastal Plain. The formation of the Ouachita Mountains is described, as is the cretaceous formations that led to biological fossils. Historic mining of minerals is also discussed. For the more technically inclined, a detailed description of the geological formations of the county is included near the end.


Fault Evolution In The Northwest Little San Bernardino Mountains, Southern California: A Reflection Of Tectonic Linkage Between The San Andreas Fault And The Eastern California Shear Zone, Ann Hislop 2019 University of Kentucky

Fault Evolution In The Northwest Little San Bernardino Mountains, Southern California: A Reflection Of Tectonic Linkage Between The San Andreas Fault And The Eastern California Shear Zone, Ann Hislop

Theses and Dissertations--Earth and Environmental Sciences

The Little San Bernardino Mountains (LSBM) Fault Set are N-S dextral faults, east of the restraining bend of the San Andreas Fault (SAF) in southern California, that may form a tectonic linkage between the SAF and the Eastern California Shear Zone. The NW LSBM are a complexly deformed structural domain characterized by the young N-S dextral faults and older NW-oriented Dillon Shear Zone faults. Before the 1992 Joshua Tree (Mw 6.1) and Landers (Mw 7.3) earthquakes, the rugged NW LSBM was the subject of few geologic studies. This bedrock mapping study has further delineated the geometry ...


Accessible Science: The Natural History Of The Connecticut River Valley, Fred Venne 2019 Amherst College

Accessible Science: The Natural History Of The Connecticut River Valley, Fred Venne

Science and Engineering Saturday Seminars

Many students take an Earth science or geology course to fulfill a requirement, knowing little to nothing about the field. Like all sciences, geology can appear to have ready answers unconnected to other areas of human endeavor, such as art, religion or philosophy. An interdisciplinary approach to teaching can ameliorate this perception for students who are intimidated by the subject and deepen understanding for those who are already excited about geology. We will examine two strategies designed to support the nature of science while scaffolding student learning in geology: research based digital resources use and museum of natural history visits ...


Modeling The Effects Of Climate Variability On Hydrology And Stream Temperatures In The North Fork Of The Stillaguamish River, Kyra Freeman 2019 Western Washington University

Modeling The Effects Of Climate Variability On Hydrology And Stream Temperatures In The North Fork Of The Stillaguamish River, Kyra Freeman

WWU Graduate School Collection

The Stillaguamish River in northwest Washington State, USA, provides water resources to local agriculture, industry and First Nations Tribes, and provides crucial habitat for several endangered species of salmonids. The watershed experiences a mild maritime climate and high relief, with rain and snowmelt dominating the streamflow. In anticipation of shifts in snowpack, streamflow, and stream temperature, I use projected global climate scenarios and numerical models to examine future climatic variability on streamflow and stream temperatures in the snow-melt dominated North Fork of the Stillaguamish River. I calibrated the physically based Distributed Hydrology Soil Vegetation Model (DHSVM) and River Basin Model ...


Quantifying The Magnitude And Spatial Variability Of Bedrock Erosion Beneath The Sisters Glacier, Washington, Using Cosmogenic 3he Concentrations, Sarah W. Francis 2019 Western Washington University

Quantifying The Magnitude And Spatial Variability Of Bedrock Erosion Beneath The Sisters Glacier, Washington, Using Cosmogenic 3he Concentrations, Sarah W. Francis

WWU Graduate School Collection

Cosmogenic 3He analyses provide a tool to infer spatial variation of cirque-glacial bedrock erosion. 3He accumulates in bedrock exposed at the surface as a result of cosmic ray bombardment; the concentration of cosmogenic 3He increases with exposure time as well as proximity to the surface. The Twin Sisters range, North Cascades, WA is an ideal location to use cosmogenic 3He to infer cirque-glacial erosion depths and rates, due to the dunite bedrock and the detailed record of Holocene glaciation from the nearby Mount Baker. We used field mapping, lidar data and aerial imagery to identify bedrock ...


The Geologic Times, Vol. 1, Sara Mana 2019 Salem State University

The Geologic Times, Vol. 1, Sara Mana

Earth Science Association

The debut issue of the Earth Science Association's newsletter, The Geologic Times.

Contents:

The Evolution of Theropod Hands as seen in a Newly Described Italian Dinosaur by Marcello Toscanini

Plate Tectonics Crossword Puzzle

Is the Great Salt Lake dying? by Alyssa B. Cassias

Structural Geology @SSU - The Story of Rafes Chasm in Magnolia, MA by Eleanor Roccio

Mineral of the Month: Tourmaline! by Klementina Mato

ESA News


Chaco Canyon, New Mexico: A Caretaker City And A Pilgrimage Destination, Larry Benson, Deanna N. Grimstead, John R. Stein, David A. Roth, Terry I. Plowman 2019 University of Colorado at Boulder

Chaco Canyon, New Mexico: A Caretaker City And A Pilgrimage Destination, Larry Benson, Deanna N. Grimstead, John R. Stein, David A. Roth, Terry I. Plowman

USGS Staff -- Published Research

Some Southwestern archaeologists continue to ascribe to the hypothesis that Chaco was agriculturally productive to the point that it could support at least a few thousand full-time residents. This paper suggests an alternative hypothesis; i.e., Chaco was marginally productive and could only support a few hundred permanent residents. Isotopic analysis of mammal teeth found in trenches cut through platform mounds fronting Pueblo Bonito indicate the possibility that much of the meat consumed by Chacoan residents and visitors came from higher elevation sites bordering the San Juan Basin. We suggest that resident population estimates based on great house room numbers ...


Publications And Other Works By R. F. Diffendal, Jr., Robert F. Diffendal 2019 University of Nebraska - Lincoln

Publications And Other Works By R. F. Diffendal, Jr., Robert F. Diffendal

Papers in Natural Resources

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Updated January 2019


Maps Showing The Physical Hydrogeology And Changes In Saturated Thickness (Predevelopment To Spring 2016 And Spring 2011 To Spring 2016) In The Middle Republican Natural Resources District, Southwestern Nebraska., Jesse T. Korus Dr., Leslie M. Howard 2019 University of Nebraska-Lincoln

Maps Showing The Physical Hydrogeology And Changes In Saturated Thickness (Predevelopment To Spring 2016 And Spring 2011 To Spring 2016) In The Middle Republican Natural Resources District, Southwestern Nebraska., Jesse T. Korus Dr., Leslie M. Howard

Conservation and Survey Division

This report accompanies fourteen new maps summarizing the hydrogeology and changes in saturated thickness in the Middle Republican Natural Resources District (MRNRD). The purpose of these maps is to assist the MRNRD in their groundwater management programs and in planning and installing an observation well network. Maps include:

• base of the principal aquifer;

• water table surfaces for predevelopment, Spring 2011, and Spring 2016;

• saturated thicknesses for predevelopment, Spring 2011, and Spring 2016;

• changes in saturated thickness (both in absolute magnitude and in percent) from predevelopment to Spring 2016 and from Spring 2011 to Spring 2016;

• transmissivity.

A series of comprehensive ...


Refining The Onset Timing And Slip History Along The Northern Part Of The Teton Fault, Rachel Montague Hoar 2019 University of Kentucky

Refining The Onset Timing And Slip History Along The Northern Part Of The Teton Fault, Rachel Montague Hoar

Theses and Dissertations--Earth and Environmental Sciences

A new apatite (U-Th)/He (AHe) dataset from subvertical transects collected in the Teton and Gallatin Ranges in the Teton-Yellowstone region provides insight for the slip history and length of the Teton fault. Along the northernmost segment of the Teton fault, inverse thermal history modeling of AHe data from Eagles Rest Peak yield a ~9 Ma age for onset of fault slip. This age supports previous interpretations that Mount Moran may be the true center of the Teton fault. This refined interpretation coupled with lengthdisplacement fault scaling analysis and previous estimates of total fault displacement (~6 km) indicates that the ...


Response Of Vegetation In Open And Partially Wooded Fens To Prescribed Burning At Seney National Wildlife Refuge, Jane E. Austin, Wesley E. Newton 2019 U.S. Department of the Interior & U.S. Geological Survey

Response Of Vegetation In Open And Partially Wooded Fens To Prescribed Burning At Seney National Wildlife Refuge, Jane E. Austin, Wesley E. Newton

Publications of the US Geological Survey

The health and function of northern peatlands, particularly for fens, are strongly affected by fire and hydrology. Fens are important to several avian species of conservation interest, notably the yellow rail (Coturnicops noveboracensis). Fire suppression and altered hydrology often result in woody encroachment, altering the plant community and structure. Woody encroachment and its effects on biodiversity have become an increasing concern in the conservation and management of plant communities. This study evaluated the effects of spring and summer prescribed burns on the plant community, cover, and structure in open and partially wooded fens at Seney National Wildlife Refuge, Michigan, using ...


Mineral Exploration And Sustainable Development: A Case Study In The Republic Of South Sudan, Cosmas Pitia Kujjo 2019 University of Kentucky

Mineral Exploration And Sustainable Development: A Case Study In The Republic Of South Sudan, Cosmas Pitia Kujjo

Theses and Dissertations--Earth and Environmental Sciences

South Sudan, a new country formed in 2011, has been planning to develop its mineral sector by allocating exploration licenses to investors. This decision requires preliminary knowledge of geology and mineral occurrences, both of which are unavailable because the country has been engaged in a civil war for more than 50 years. Exploration of mineral resources in South Sudan has lagged behind its petroleum industry, except for artisanal gold mining, which is practiced intermittently by local communities. Freely available satellite gravity and remote-sensing data were used to map the basement architecture as well as zones of hydrothermal alteration in the ...


Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford 2019 Wilfrid Laurier University

Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford

Theses and Dissertations (Comprehensive)

The Marian Watershed Stewardship Program (MWSP), a community-driven aquatic ecosystem monitoring program, was developed by the Tłı̨chǫ Government to address concerns regarding the cumulative impacts of multiple potential stressors. In particular, the MWSP aims to develop methods that will be effective for detecting potential pollution from the proposed cobalt-gold-copper-bismuth NICO mine within Tłı̨chǫ Lands. In collaboration with the MWSP, paleolimnological methods and geochemical normalization are used to establish pre-mine baselines of lake sediment metals concentrations in the Marian River watershed prior to mine development. This baseline framework can be used to assess for pollution from surficial sediment once ...


Bacterial Lipids In Holocene Sediments From Baffin Island: Insights Into Temperature Reconstructions In Arctic Environments, Lucy Camuti 2019 University of Colorado, Boulder

Bacterial Lipids In Holocene Sediments From Baffin Island: Insights Into Temperature Reconstructions In Arctic Environments, Lucy Camuti

Undergraduate Honors Theses

This research study assesses the validity of bacterial branched glycerol dialkyl glycerol tetraethers (brGDGTs) for temperature reconstructions in Arctic settings from a sediment core extracted from Brother of Fog lake, Baffin Island. The distribution of brGDGTs in lake sediments have been shown to correlate with mean annual air temperature (MAAT) and serve as a proxy for paleotemperature reconstructions. This study aims to reconstruct temperature variability over the Holocene (~11500 years) and the applicability of this proxy for high latitude lakes. The results show a large bias within the brGDGT-inferred temperature reconstruction when applying the Russell et al. 2018 calibration. Due ...


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