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Full-Text Articles in Earth Sciences

A Spatial Relationship Between Stream Slope Stability And Water Quality Within An Urban Watershed In Rock Island, Il, Joseph Teresi May 2017

A Spatial Relationship Between Stream Slope Stability And Water Quality Within An Urban Watershed In Rock Island, Il, Joseph Teresi

Celebration of Learning

The consistently observed phenomenon of highly altered streams and degraded water quality draining urban areas across the U.S is described as the urban stream syndrome. Rock Island, Illinois, contains a population of nearly 39,000 people, and houses industrial and logistical businesses amidst a city of aging infrastructure. Streams occupy ravines that have incised into the Quaternary loess plateau, flowing south towards the Rock River and north or west towards the Mississippi River. In an attempt to understand better the severity of Rock Island’s urban stream syndrome, this project analyzed stream slopes within the Rock Island watershed to categorize their level …


Evaluating Fault-Line Escarpment Exposure In The Guadalupe Mountains Of West Texas And New Mexico, Audrey Anne Happel May 2017

Evaluating Fault-Line Escarpment Exposure In The Guadalupe Mountains Of West Texas And New Mexico, Audrey Anne Happel

Theses and Dissertations

The Permian stratigraphy of the Guadalupe Mountains is well-known due to the impeccable exposure of Permian strata along distinct escarpments that define the boundaries of the range. Even though the Permian strata have been closely examined to understand the associated petroleum reservoirs in the adjacent Delaware basin, little work has been done on the escarpments that expose the well-known rocks at the surface by way of tectonic and erosional processes. The development of escarpments are directly affected by multiple processes that create the landscape, and can be used as a tool to temporally and spatially constrain tectonic and erosional activity …


Geoscientists-In-The-Park Summer Internship Mapping Shoreline Change With The National Park Service, Michael P. Endicott May 2017

Geoscientists-In-The-Park Summer Internship Mapping Shoreline Change With The National Park Service, Michael P. Endicott

Sustainability and Social Justice

This project paper details the activities carried out as a Geologist/GIS Specialist in the Gateway National Recreation Area as a part of the Geoscientists-In-The-Park internship program. The focus of this position was on supporting the geomorphological monitoring efforts of the National Park Service. This was accomplished through a combination of field data collection, GIS analysis, report writing, and project work. By the end of the internship, substantial progress was made to the formation of Gateway’s Annual 1D and 2D report for 2015-2016, field data were collected for the 2016 summer season, changes in geomorphology were explored and summarized for the …


Rock Art Management And Landscape Change: Mixed Field Assessment Techniques For Cultural Stone Decay, Kaelin M. Groom May 2017

Rock Art Management And Landscape Change: Mixed Field Assessment Techniques For Cultural Stone Decay, Kaelin M. Groom

Graduate Theses and Dissertations

As tourism continues to grow as one of the world’s most ubiquitous markets, the development and promotion of non-invasive techniques for cultural stone decay analysis and landscape change are vital to establishing conditional base-lines to best aid cultural heritage management (CRM) efficacy. Using rock art as a medium, this dissertation presents three independent case studies employing the Rock Art Stability Index (RASI) and repeat photography to explore the merits of mixed rapid field assessment techniques in relation to CRM and heritage tourism. While rock art is only one example of irreplaceable world heritage resources, examining how they decay and what …


Assessing Landslide Susceptibility With Gis Using Qualitative And Quantitative Methods In Knox County, Nebraska, Christian J. Cruz May 2017

Assessing Landslide Susceptibility With Gis Using Qualitative And Quantitative Methods In Knox County, Nebraska, Christian J. Cruz

Department of Geography: Dissertations, Theses, and Student Research

This thesis assesses landslide susceptibility using data from LiDAR DEMs, land cover, and soil surveys. Data were assessed quantitatively through Bayesian logistic regression within a geographic information system (GIS) and statistical software to produce a landslide susceptibility map. The study area exhibits moderate relief where bluffs along the Missouri River valley gradually recede into rolling loess-mantled hills further to the south and southeast in Knox County. The six factors used to determine susceptibility to landslides are: land cover, parent material, slope aspect, slope curvature slope degree, and soil series. My findings show an increase in slope is the most significant …


Geomorphic Effects Of Logging Railbeds On An Ozarks Headwater Stream, Mark Twain National Forest, Missouri, Nickolas S. Bradley May 2017

Geomorphic Effects Of Logging Railbeds On An Ozarks Headwater Stream, Mark Twain National Forest, Missouri, Nickolas S. Bradley

Graduate Theses/Dissertations

Geomorphic characteristics of headwater streams draining the Missouri Ozarks have not been studied as much as larger rivers in the region. Further, while the effects of historical logging on channel form and sediment supply have been identified, no studies have investigated the effects of logging tramways constructed along Ozark headwater rivers. This study examines the geomorphic characteristics and channel disturbances of Tram Hollow (1.67 km2) within the Mark Twain National Forest in the Ozark Highlands. The purpose of this study is to classify and quantify natural and disturbed channel morphology in Tram Hollow which has been affected by …


Comparison Of Flow Dynamics And Bifurcation Angles In Tributary And Distributary Channel Networks, Thomas Coffey May 2017

Comparison Of Flow Dynamics And Bifurcation Angles In Tributary And Distributary Channel Networks, Thomas Coffey

Graduate Theses and Dissertations

The dynamics of channel mouth bifurcations on river deltas can be understood using theory developed in tributary channel networks. Bifurcations in groundwater-fed tributary networks have been shown to evolve dependent on diffusive ground water flow patterns

directly adjacent to the channel network, producing a critical angle of 72°. We test the hypothesis that bifurcation angles in distributary channel networks are likewise dictated by a diffusive external flow field, in this case the shallow surface water surrounding the subaqueous portion of distributary channels in a deltaic setting. We measured 25 unique distributary bifurcations in an experimental delta and 197 bifurcations in …


The Groundwater Atlas Of Richardson County, Nebraska, Dana P. Divine, Leslie M. Howard May 2017

The Groundwater Atlas Of Richardson County, Nebraska, Dana P. Divine, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

The purpose of this groundwater atlas is to synthesize a wealth of hydrogeologic data for Richardson County that has not been published in readily accessible formats previously. Many of the maps presented herein are based on data from registered well logs and test hole logs that are publicly available on-line, which become more valuable when compiled, analyzed, and discussed as a whole. The focus of the maps presented in this report is the accessibility of groundwater for pumping.


Geomorphic Characteristics And Sediment Transport In Natural And Channelized Reaches Of Big Barren Creek, Southeast Missouri, Matthew S. Thies May 2017

Geomorphic Characteristics And Sediment Transport In Natural And Channelized Reaches Of Big Barren Creek, Southeast Missouri, Matthew S. Thies

Graduate Theses/Dissertations

Channelization, levee construction, and gravel mining are land management practices that are used for flood control. However, they often alter the balance between sediment supply and available sediment transporting power in streams, causing channel instability. Streams can respond to instability through channel incision and sediment aggradation which can degrade riparian habitat, increase flood risks, and cause property damage. These problems have been observed along segments of Big Barren Creek, which drains 190 km² of the Missouri Ozarks in Mark Twain National Forest. Field assessment and modeling methods were used to evaluate the spatial distribution of channel instability along the upper …


Timing Of Speleogenesis Of Las Karmidas Cave (Mexico): First Description Of Pseudokarst Developed In Ignimbrite, María Del Pilar Aliaga-Campuzano, Rafael López-Martínez, Pablo Dávila-Harris, Ramón Espinasa-Pereña, Adriana Espino Del Castillo, J.P. Bernal Apr 2017

Timing Of Speleogenesis Of Las Karmidas Cave (Mexico): First Description Of Pseudokarst Developed In Ignimbrite, María Del Pilar Aliaga-Campuzano, Rafael López-Martínez, Pablo Dávila-Harris, Ramón Espinasa-Pereña, Adriana Espino Del Castillo, J.P. Bernal

International Journal of Speleology

Las Karmidas Cave (Puebla State, Mexico) is an unusual type of pseudokarstic cavity generated by piping and erosive processes within the contact of a diamicton and an overlying Quaternary ignimbrite. Morphological evidence suggests that the cave was developed in two stages: a phreatic stage and a vadose stage. The latter was characterized by the formation of carbonate speleothems. The absolute upper-age limit for the cave (168 +7.1/-7.5 ka) was established by U-Th dating of zircons grains extracted from the overlying ignimbrite, whilst a minimum age for the transition from a phreatic to vadose regime (95.6 ± 2.1 ka) was constrained …


Developing A Tree-Ring Chronology For Reconstructing Past Climate Conditions: Coral Pink Sand Dunes, Ut, Amy L. Cutter Apr 2017

Developing A Tree-Ring Chronology For Reconstructing Past Climate Conditions: Coral Pink Sand Dunes, Ut, Amy L. Cutter

McNair Scholars Research Journal

The Coral Pink Sand Dunes (CPSD) is one of the largest active dune fields in the Grand Staircase of the Colorado Plateau. A disjunct stand of ponderosa pine (Pinus ponderosa) seemingly thrives within the dune field. The presence of a multiple-aged stand suggests the site has experienced varied climatic conditions since becoming established. Other geomorphic systems in the region (e.g., arroyos) indicate sensitivity to small climate fluctuations; perhaps the dunes are similarly sensitive, leading to the question—could the trees be used to reconstruct past climate, and could that reconstruction be used to model dune activity with climate variability. The climate-growth …


A Numerical Model Investigation Of The Role Of The Glacier Bed In Regulating Grounding Line Retreat Of Thwaites Glacier, West Antarctica, Michael Scott Waibel Mar 2017

A Numerical Model Investigation Of The Role Of The Glacier Bed In Regulating Grounding Line Retreat Of Thwaites Glacier, West Antarctica, Michael Scott Waibel

Dissertations and Theses

I examine how two different realizations of bed morphology affect Thwaites Glacier response to ocean warming through the initiation of marine ice sheet instability and associated grounding line retreat. A state of the art numerical ice sheet model is used for this purpose. The bed configurations used are the 1-km resolution interpolated BEDMAP2 bed and a higher-resolution conditional simulation produced by John Goff at the University of Texas using the same underlying data. The model is forced using a slow ramp approach, where melt of ice on the floating side of the grounding line is increased over time, which gently …


Results Of Test-Hole Drilling For Observation Well Planning In The Upper Loup Natural Resources District, Fall 2016, Douglas Hallum, Sue Olafsen Lackey Mar 2017

Results Of Test-Hole Drilling For Observation Well Planning In The Upper Loup Natural Resources District, Fall 2016, Douglas Hallum, Sue Olafsen Lackey

Conservation and Survey Division: Faculty and Staff Publications

The High Plains Aquifer underlies much of Nebraska (Figure 1). It is the primary source of groundwater within the Upper Loup Natural Resources District (ULNRD) of central Nebraska (Figure 2). Water derived from the aquifer is an important natural resource for the area and supplies water for recreation, wildlife and agriculture, as well as domestic, municipal, and industrial uses. A general lack of water level observations in the region (Figure 3), recently developed groundwater irrigated acres along the upper Calamus River (Figure 4), falling spring water levels measured in existing irrigation wells (Figure 5), and a stable to falling stream …


Evaporite Karst In Italy: A Review, Jo De Waele, Leonardo Piccini, Andrea Columbu, Giuliana Madonia, Marco Vattano, Chiara Calligaris, Ilenia D’Angeli, Mario Parise, Mauro Chiesi, Michele Sivelli, Bartolomeo Vigna, Luca Zini, Veronica Chiarini, Francesco Sauro, Russell Drysdale, Paolo Forti Mar 2017

Evaporite Karst In Italy: A Review, Jo De Waele, Leonardo Piccini, Andrea Columbu, Giuliana Madonia, Marco Vattano, Chiara Calligaris, Ilenia D’Angeli, Mario Parise, Mauro Chiesi, Michele Sivelli, Bartolomeo Vigna, Luca Zini, Veronica Chiarini, Francesco Sauro, Russell Drysdale, Paolo Forti

International Journal of Speleology

Although outcropping rarely in Italy, evaporite (gypsum and anhydrite) karst has been described in detail since the early 20th century. Gypsum caves are now known from almost all Italian regions, but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche), Calabria, and Sicily, where the major outcrops occur. Recently, important caves have also been discovered in the underground gypsum mines in Piedmont. During the late 80s and 90s several multidisciplinary studies were carried out in many gypsum areas, resulting in a comprehensive overview, promoting further research in these special karst regions. More recent …


Application Of Numerical Modeling To Study River Dynamics: Hydro-Geomorphological Evolution Due To Extreme Events In The Sandy River, Oregon, Sarkawt Hamarahim Muhammad Mar 2017

Application Of Numerical Modeling To Study River Dynamics: Hydro-Geomorphological Evolution Due To Extreme Events In The Sandy River, Oregon, Sarkawt Hamarahim Muhammad

Dissertations and Theses

The Sandy River (OR) is a coastal tributary of the Columbia River and has a steep hydroshed 1316 square kilometers which is located on the western side of Mount Hood (elevation range 3 m to 1800 m). The system exhibits highly variable flow: Its average discharge is ~40 m3/s, and the highest recorded discharge was 1739 m3/s in 1964. In this study I model the geomorphic sensitivity of an 1800m reach located the downstream of the former Marmot Dam, which was removed in 2007. The hydro-geomorphic response to major flood has implications for system management and …


The Dynamic Geomorphic Setting Of The Late Pleistocene Hartley Mammoth Site: Burial And Skeletal Preservation In A Slump-Block Depression Near Abiquiu, New Mexico, Jennifer K. Muus Mar 2017

The Dynamic Geomorphic Setting Of The Late Pleistocene Hartley Mammoth Site: Burial And Skeletal Preservation In A Slump-Block Depression Near Abiquiu, New Mexico, Jennifer K. Muus

Earth and Planetary Sciences ETDs

Near Abiquiu in northern New Mexico, the skeletal remains of two mammoths were discovered in the summer of 2014 in the near-surface deposits of a very small alluvial channel. The channel occupies a depression on the backtilted top of a Toreva slump block, a highly unusual setting for a mammoth burial. Geomorphological investigation of the site has provided insight into processes leading to burial and preservation of the remains, as well as local environmental change. Field mapping of sediment sources and LiDAR scans of the contributing slope basin and slump bench provided a map of geomorphic features and surficial geologic …


Unusual Geologic Evidence Of Coeval Seismic Shaking And Tsunamis Shows Variability In Earthquake Size And Recurrence In The Area Of The Giant 1960 Chile Earthquake, M. Cisternas, E. Garrett, R. Wesson, T. Dura, Lisa L. Ely Mar 2017

Unusual Geologic Evidence Of Coeval Seismic Shaking And Tsunamis Shows Variability In Earthquake Size And Recurrence In The Area Of The Giant 1960 Chile Earthquake, M. Cisternas, E. Garrett, R. Wesson, T. Dura, Lisa L. Ely

All Faculty Scholarship for the College of the Sciences

An uncommon coastal sedimentary record combines evidence for seismic shaking and coincident tsunami inundation since AD 1000 in the region of the largest earthquake recorded instrumentally: the giant 1960 southern Chile earthquake (Mw 9.5). The record reveals significant variability in the size and recurrence of megathrust earthquakes and ensuing tsunamis along this part of the Nazca-South American plate boundary. A 500-m long coastal outcrop on Isla Chiloé, midway along the 1960 rupture, provides continuous exposure of soil horizons buried locally by debris-flow diamicts and extensively by tsunami sand sheets. The diamicts flattened plants that yield geologically precise ages to correlate …


The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair Feb 2017

The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair

Electronic Theses and Dissertations

The Tuscaloosa Marine Shale (TMS) was deposited across southern Louisiana and Mississippi during the Upper Cretaceous. The study focuses on a core region containing vast deposits of Cretaceous-aged sediments that have economic importance for oil and gas exploration. This region has been conventionally drilled for decades, focusing on the recovery of the Cretaceous hydrocarbons. Explorers within this region had traditionally targeted the massive sand units of the Lower and Upper Tuscaloosa Group while neglecting the middle Tuscaloosa Marine Shale unit. With the onset of unconventional drilling technology, new explorers to the region have begun to delineate the Tuscaloosa Marine Shale’s …


Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa, Jozsef Szilagyi Feb 2017

Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa, Jozsef Szilagyi

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Secondary Minerals From Salt Caves In The Atacama Desert (Chile): A Hyperarid And Hypersaline Environment With Potential Analogies To The Martian Subsurface, Jo De Waele, Cristina Carbone, Laura Sanna, Marco Vattano, Ermanno Galli, Francesco Sauro, Paolo Forti Jan 2017

Secondary Minerals From Salt Caves In The Atacama Desert (Chile): A Hyperarid And Hypersaline Environment With Potential Analogies To The Martian Subsurface, Jo De Waele, Cristina Carbone, Laura Sanna, Marco Vattano, Ermanno Galli, Francesco Sauro, Paolo Forti

International Journal of Speleology

Over the past 15 years several expeditions by French, American and especially Italian cavers have unveiled over 50 caves in the Cordillera de la Sal (Atacama Desert, Northern Chile). Many of these caves contain a variety of speleothems and minerals, some of which have rarely been observed within karst systems. Most of the secondary deposits in these caves are composed of halite, but also other halide, carbonate, sulphate, nitrate, phosphate, and silicate minerals have been found. Among the sixteen cave mineral species recognized, atacamite, darapskite, blödite, leonite, anhydrite, and especially antarcticite are worth mentioning. In one of the samples an …


Effects Of Spatially Distributed Stream Power On Check Dam Function In Small Upland Watersheds: A Case Study Of The Upper Laja Watershed, Guanajuato, Mexico, Zachary Andrew Herzfeld Jan 2017

Effects Of Spatially Distributed Stream Power On Check Dam Function In Small Upland Watersheds: A Case Study Of The Upper Laja Watershed, Guanajuato, Mexico, Zachary Andrew Herzfeld

Dissertations and Theses

Watershed restoration comes in a variety of forms depending on which set of problems are sought to be remedied. Severe soil erosion, in the form of gullying and/or headcutting, can be mitigated through constructing check dams in well-selected locations. This practice has been used throughout the upland subwatersheds within the Upper Laja River watershed in Guanajuato, México. The present study employed Wolman pebble counts to systematically assess the effectiveness of 21 check dams located near the city of San Miguel de Allende. Particle size distributions taken directly downstream and upstream of each check dam were differentiated, aggregated and compared--with the …


Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance, Veronica Chiarini, Isabelle Couchoud, Russell Drysdale, Petra Bajo, Simone Milanolo, Silvia Frisia, Alan Greig, John Hellstrom, Jo De Waele Jan 2017

Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance, Veronica Chiarini, Isabelle Couchoud, Russell Drysdale, Petra Bajo, Simone Milanolo, Silvia Frisia, Alan Greig, John Hellstrom, Jo De Waele

International Journal of Speleology

Detailed petrographic observations have been coupled with trace element and δ13C - δ18O analyses in order to investigate their dynamics in two Holocene Bosnian speleothems. The potential of this multiproxy approach in providing a means to extract palaeo-environmental information from stalagmites whose stable isotope signals are noisy and without obvious trends has been tested. The studied stalagmites are mostly characterized by columnar microcrystalline fabric. At the sub-millimetre scale of lamination, different microcrystalline columnar sub-types (open and closed) have been detected and classified on the basis of the observed porosity and the crystallite size. The presence of …


2016/17 Dry Run Creek Geomorphological Watershed Assessment, University Of Northern Iowa. Department Of Earth And Environmental Sciences. Jan 2017

2016/17 Dry Run Creek Geomorphological Watershed Assessment, University Of Northern Iowa. Department Of Earth And Environmental Sciences.

UNI Conservation Corps Projects

Dry Run Creek (DRC) watershed is a primary drainage basin located in northwestern Black Hawk County (Figure 1). It is fed predominantly by agricultural runoff in its upper reaches, and becomes heavily urbanized as it travels through the city of Cedar Falls, before draining into the Cedar River. The stream is perennial, however some are tiled and new segments have developed both naturally and artificially. Re-evaluation of the creek is underway and indicates some changes in urban and rural areas. Data was collected between Fall 2016 & Fall 2017 by University of Northern Iowa geomorphology students, using handheld GPS devices …


Nebraska, Usa: Wonderful Fossils, Natural History Museums And Public Art Depicting Fossils, Robert F. Diffendal Jr. Jan 2017

Nebraska, Usa: Wonderful Fossils, Natural History Museums And Public Art Depicting Fossils, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nebraska is known by vertebrate palaeontologists as the place in North America where there is a very complete Cenozoic geologic record of mammalian evolution over the last thirty-five million years or so. All you have to do is visit any of the many major natural history museums in the USA and in many countries around the world, including the UK, to see fossil skulls, articulated skeletons and large slabs of rock containing bones of fossil mammals from Nebraska to verify this assertion. Nebraska is also the site of Cretaceous rocks containing the oldest known Cretaceous fossil flower and many other …


Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc Jan 2017

Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc

Geography & Environment Publications

A Froude‐scaled physical model of a proximal gravel‐bed braided river was used to connect the river morphological characteristics, and sedimentary processes and forms, to deposit geometry. High resolution continuous three‐dimensional topographic data were acquired from sequential photogrammetric digital elevation models paired with grain‐size surface maps derived from image analysis of textural properties of the surface. From these data, the full three‐dimensional development of the braided river deposit and grain‐size sorting patterns was compiled over an experimental time period of 41 h during which the model river reworked a large portion of the braided channel. The minimum surface of the deposit …


Natural And Human-Induced Variability In Barrier-Island Response To Sea Level Rise, Jennifer Miselis, Jorge Lorenzo Trueba Jan 2017

Natural And Human-Induced Variability In Barrier-Island Response To Sea Level Rise, Jennifer Miselis, Jorge Lorenzo Trueba

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Storm-driven sediment fluxes onto and behind barrier islands help coastal barrier systems keep pace with sea level rise (SLR). Understanding what controls cross-shore sediment flux magnitudes is critical for making accurate forecasts of barrier response to increased SLR rates. Here, using an existing morphodynamic model for barrier island evolution, observations are used to constrain model parameters and explore potential variability in future barrier behavior. Using modeled drowning outcomes as a proxy for vulnerability to SLR, 0%, 28%, and 100% of the barrier is vulnerable to SLR rates of 4, 7, and 10 mm/yr, respectively. When only overwash fluxes are increased …


2016 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, Connie Reimers-Hild Jan 2017

2016 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, Connie Reimers-Hild

Conservation and Survey Division: Faculty and Staff Publications

The effective management of Nebraska’s water resources is evermore challenged by variations in weather, climate, technology, socioeconomic policies, and regulation. Anthropogenic climate change, declining water tables and stream flows, increasing demands on freshwater, aging water infrastructure, fiscal constraints, and impacts on aquatic organisms are particularly imminent challenges in Nebraska and around the world (Pahl-Wostl et al., 2013; Pittock et al., 2008; USACE, 2010). Sustaining freshwater ecosystem services in the face of emerging environmental threats presents an immense societal dilemma worldwide (Pittock et al., 2013; Rockström et al., 2009, Millenium Ecosystem Assessment, 2005). The rapidly changing conditions of water resources in …


Sedimentary Responses To Growth Fault Slip And Clay Shrink And Swell Induced Elevation Variations: East Matagorda Peninsula, Texas, Wei Ji Jan 2017

Sedimentary Responses To Growth Fault Slip And Clay Shrink And Swell Induced Elevation Variations: East Matagorda Peninsula, Texas, Wei Ji

Theses and Dissertations--Earth and Environmental Sciences

East Matagorda Peninsula in southwestern Texas is characterized geologically by active, regional-scale and near-surface growth faulting. Decimeter scale (up to 0.42 m) vertical displacement was recorded at the study site over a period of four years, not believed to be associated with growth faulting. This research tested the hypotheses that fault slip rates were correlated with sediment accumulation rates, and that the observed vertical displacement was produced by shrink-and-swell clays in near surface sediments. To quantify sediment accumulation rates, a suite of radionuclides (7Be, 137Cs, and 210Pb) were used. To understand the effects of shrink-and-swell clays, …


Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo Jan 2017

Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo

Theses and Dissertations--Earth and Environmental Sciences

Tropical wetlands such as the Pantanal help regulate global biogeochemical cycles, but climate change is modifying these environments. Controls on environmental changes can potentially be assessed from ancient, well-dated lacustrine sedimentary records. An integrated field and laboratory approach was undertaken to study the limnogeology of Lake Uberaba in the northern Pantanal, and test whether the lake has preserved a reliable record of environmental change in its strata. This study was designed to understand how the basin accumulates sediment and to assess its sensitivity to hydroclimatic variability. The data showed that modern Lake Uberaba is a highly dynamic, freshwater fluvial-lacustrine basin. …


Catastrophic Landscape Modification From Massive Landslide Tsunamis: An Example From Taan Fiord, Alaska, Colin Bloom Jan 2017

Catastrophic Landscape Modification From Massive Landslide Tsunamis: An Example From Taan Fiord, Alaska, Colin Bloom

All Master's Theses

The October 17th 2015 Taan landslide and tsunami generated a high runup of 192 m, nearly an order of magnitude greater than most previously surveyed tsunamis. Extensive modifications observed and documented on several low gradient fan deltas within the fiord make Taan Fiord an excellent laboratory for characterizing geomorphic signatures of a high runup tsunami event. Although interest in this topic is high, most prior post-tsunami surveys are from earthquake-generated tsunamis with relatively low runup, thus the geomorphic signatures of high runup tsunamis or their potential for preservation are uncharacterized. Additionally, clear modifications described during post-tsunami surveys are typically …