Geomorphology Commons^™

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;

• …

Geology Of Southeastern Nebraska, Robert Matthew Joeckel, Dana Divine, Leslie M. Howard, Kathleen Cameron, Michele M. Waszgis

Conservation and Survey Division

No abstract provided.

Mapping And Reconstructing The Paleotsunami Record In Queule, South-Central Chile, Pedro I. Matos Llavona

All Master's Theses

Records of past tsunamis help constrain the long-term characteristics of megathrust earthquakes and elucidate the role of sea-level in the preservation of tsunami deposits. Near Queule, south-central Chile (39.3˚S, 73.2˚W), three sand layers interpreted as tsunami deposits are interbedded with dark, organic-rich, silt deposits along a tidal channel landward of a sand spit capped by eolian sand dunes. The uppermost sand layer is attributed to the tsunami from the Mw 9.5 1960 earthquake. The sand layer is widespread, tabular, oxidized, thins landward, and generally occurs at a depth of <20 cm. The spatial distribution of the deposit corresponds closely with the extent of the 1960 tsunami sand on 1961 aerial photographs. We computed numerical simulations of the 1960 tsunami in Queule using the GeoClaw finite-slip hydrodynamic model based on three published earthquake sources. The simulations showed inundation up to 4km inland that overtopped the coastal dunes; agreeing with historical documentation and testimonies of 1960 tsunami survivors. Stratigraphically below the 1960 tsunami deposit are two tabular, landward-thinning sand layers with sharp lower contacts above silty organic-rich layers. Combined radiocarbon ages of seeds, charcoal and wood fragments found at the contacts with the underlying organic layers yielded ages of 5460-5320 and 5990-5910 cal. years BP. These sand layers have similar distribution patterns to the 1960 sand layer, but are finer grained, thinner and less oxidized. Below this sequence of interbedded tsunami sands and silty organic layers there is an abrupt contact underlain by a distinct sequence of four inorganic silt layers alternating with dark brown organic-rich silts, which are older than 6280-6110 cal. years BP. The deepest studied layer is a thick, fine, gray sand. We interpret the gray sand as a submarine environment during the mid-Holocene sea-level high stand, and the alternating inorganic and organic silts as tidal to shallow sub-tidal environments, possibly indicating co-seismic land-level changes. Gradual sea level fall after the deposition of the two paleotsunami sand deposits that changed the geomorphology of the coast and limited the accommodation space necessary to preserve additional overwash sediments could explain the 5000-year hiatus with no evidence of earthquakes or tsunamis. Further research will offer possible explanations for the exception of the 1960 tsunami in breaking this long-term pattern.

Identifying Key Factors Affecting Translational Landslides In Part Of The Yakima Fold And Thrust Belt, Washington State, Joseph Schilter

All Master's Theses

Washington has one of the fastest growth rates in the nation, and unfortunately also is among the most landslide-prone states. With increased population density and urban sprawl, the need for landslide hazard assessment grows. On the Columbia Plateau in central Washington, the smooth rigid, inclined surfaces of the Columbia River Basalts (CRBs) with loose sediment layers between them induces landslides of large blocks of bedrock. These hazards remain poorly understood, but their significance was heightened by the 2017 Rattlesnake Hills Landslide that currently threatens a community and an interstate highway south of Yakima, Washington. I propose that the strongest influences …

Holocene Periods Of Aggradation And Incision, Hanson Creek, Washington, Levi Earl Windingstad

All Master's Theses

The causes and timing of cycles of aggradation and incision in the Hanson Creek drainage in central Washington provide insight into changes in channel morphology and paleoenvironment within the region over the last 8000 years. Stratigraphically and spatially coincident archaeological evidence reveals information related to human occupation during the latter half of the epoch. Using LiDAR imagery and field surveys, recent processes such as degree of modern channel incision, accumulation of valley floor sediment, channel morphology and gradient were evaluated. The spatial distribution of these channel characteristics was assessed in relation to proximal landforms such as colluvial deposits, basalt outcrops, …

Flood-Inundation Maps For The North Platte River At Scottsbluff And Gering, Nebraska, 2018, Kellan R. Strauch

Publications of the US Geological Survey

Digital flood-inundation maps for an 8.8-mile reach of the North Platte River, from 1.5 miles upstream from the Highway 92 bridge to 3 miles downstream from the Highway 71 bridge in Scottsbluff County, were created by the U.S. Geological Survey (USGS) in cooperation with the Cities of Scottsbluff and Gering, Nebraska. The flood-inundation maps, which can be accessed through the Flood Inundation Mapping (FIM) Program website at https://www.usgs.gov/mission-areas/water-resources/science/flood-inundation-mapping-fim-program?qt-science_center_objects=0#qt-science_center_objects, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the North Platte River at Scottsbluff, Nebr. (station number 06680500). Near-real-time …

Cliff-Top Dunes In The Lower Chippewa River Valley Of West-Central Wisconsin, Jason Millett

All Graduate Theses, Dissertations, and Other Capstone Projects

The purpose of this Master’s thesis is to investigate recently identified cliff-top sand dunes located within the Lower Chippewa River Valley (LCRV), Wisconsin, USA. Research within the LCRV notes the existence of a variety of aeolian deposits, but a comprehensive explanation of their complete spatial distribution, genesis, age, and paleoenvironmental significance does not exist. In particular, stabilized cliff-top dunes with a parabolic form remain poorly understood. This problem is exacerbated by a lack of clarity in the literature regarding the genesis of dunes in a cliff-top position. Therefore, this thesis begins by reviewing the literature concerning sand dunes in cliff-top …

Mass Wasting Investigation And Assessment In The Midwest: Case Study Of The Minnesota River Valley, New Ulm To St. Peter, Minnesota, Usa, Melissa Kohout

All Graduate Theses, Dissertations, and Other Capstone Projects

Many mass- wasting studies have been conducted worldwide, however, investigations have focused in mountainous or coastal regions. This has proven problematic in areas lacking those features yet are experiencing mass wasting. Several anthropogenic risks, economic loss, and environmental issues are associated with mass wasting such as destruction of property, loss of life, and sediment pollution. The midwestern USA, is generally considered a low relief region, therefore limited data exist for mass wasting occurrence. Within the last decade, however, several events have occurred across Minnesota with little understanding of the ongoing hillslope processes leading to failure. The Minnesota River valley is …

Peatlands And Histosols In Canaan Valley National Wildlife Refuge, West Virginia, Mitzy Leigh Schaney

Graduate Theses, Dissertations, and Problem Reports

Canaan Valley in West Virginia contains a greater area of peatlands than any other locality in the mid-Atlantic Highlands. Extensive fieldwork focused on peat stratigraphy and pedology, combined with high-resolution radiocarbon dating, was used to evaluate five peatlands within Canaan Valley National Wildlife Refuge (CVNWR) in the central Appalachian Mountains. One hundred soil cores were profiled and described, 30 with laboratory data, including 52 radiocarbon dates. Calibrated basal peat dates among the five mapped peatlands indicate a late Pleistocene timeframe for the onset of peat genesis, ranging from ~18,600 to ~15,200 cal yr BP. The dates for peat initiation are …

Influence Of Large Wood On Sediment Routing In A Mixed Bedrock-Alluvial Stream, Robin Welling

Graduate Student Theses, Dissertations, & Professional Papers

Sediment storage by instream wood in forested mountain streams mediates sediment movement from hillslopes through the channel network and can alter channel morphology at multiple spatial scales. Mixed bedrock-alluvial channels are prevalent in mountain stream networks, yet the distribution and geomorphic impact of large wood within these streams are poorly understood. To estimate how the distribution of large wood in a mixed bedrock-alluvial stream relates to sediment storage, we measured and characterized large wood, and surveyed the volume of associated sediment within a stream in the Bitterroot Mountains, Montana. The upstream portion of the study reach is predominantly alluvial and …

Stream Dynamics In The Headwaters Of Post-Glacial Watershed Systems, Brett Gerard

Electronic Theses and Dissertations

This dissertation summarizes research examining watershed processes across Northern New England, with an emphasis on the Central and Coastal regions of Maine. The research presented here focuses on the linkages between watershed geomorphic conditions, climate, and surface flow regimes driving stream channel hydraulic conditions and bed dynamics governing channel geometry. The geologic and human history of the landscape provides the context in which earth surface processes are examined within the dominant physiographic settings in Maine to describe vulnerabilities to climate change. Results are summarized to support the development of sustainability solutions for forecasted watershed management problems by natural resource management …

Geomorphology Of Shell Ridges And Their Effect On The Stabilization Of The Biloxi Marsh, East Louisiana, Frances R. Crawford

University of New Orleans Theses and Dissertations

Extensive shell ridges frame the edges of marsh platforms in parts of the Biloxi Marsh of southeast Louisiana. The exact sources of the shells in these accumulations have not been clearly identified but the most likely source is a combination of shells from modern offshore and shells excavated from buried St. Bernard delta deposits. Larger or fetch-protected ridges remain stable through time, whereas ridges facing open water are more mobile, moving as much as 38 m inland from July 2017 to January 2018. Behind stable ridges, marsh platform biomass is relatively unaffected. When ridges are mobile, vegetation is smothered, leaving …

The Effects Of Sediment Properties On Barrier Island Morphology And Processes: A Numerical Modeling Experiment, Brittany Kime

University of New Orleans Theses and Dissertations

Barrier island restoration and nourishment is necessary for sustaining coastal systems worldwide. In the Mississippi River Delta Plain, the lack of sediment supply, relative sea level rise, and reworking of abandoned delta lobes promote rapid disintegration of barriers, which can contribute to mainland storm impacts. Barrier island restorations that utilize higher quality sediments (Outer Continental Shelf- OCS) are expected to exhibit higher resiliency, withstanding coastal erosion, event-induced erosion, and ongoing transgression when compared to barriers nourished using lower quality nearshore (NS) sands. Additionally, use of OCS sediments increases sediment supply by adding material to the system supporting increased barrier longevity …

Assessing Ground Penetrating Radar’S Ability To Image Subsurface Characteristics Of Icy Debris Fans In Alaska And New Zealand, Robert W. Jacob, Jeffrey M. Trop, R. Craig Kochel

Faculty Journal Articles

Icy debris fans have recently been described as fan shaped depositional landforms associated with (or formed during) deglaciation, however, the subsurface characteristics remain essentially undocumented. We used ground penetrating radar (GPR) to non-invasively investigate the subsurface characteristics of icy debris fans (IDFs) at McCarthy Glacier, Alaska, USA and at La Perouse Glacier, South Island of New Zealand. IDFs are largely unexplored paraglacial landforms in deglaciating alpine regions at the mouths of bedrock catchments between valley glaciers and icecaps. IDFs receive deposits of mainly ice and minor lithic material through different mass-flow processes, chiefly ice avalanche and to a lesser extent …

Post-Fire Variation In Aeolian Deposition In The Northern Great Basin, Clayton Roehner

Boise State University Theses and Dissertations

Aeolian processes play a significant role in the redistribution of sediment and nutrients in sparsely vegetated sagebrush-steppe ecosystems. When fire is introduced to the landscape, decreased surface roughness and associated threshold friction velocities allow for the increased mobility of surface sediments and burnt organic material, mobilizing previously stable material. Once material is entrained, interactions between a dynamic atmosphere and complex topography control the spatial distribution of aeolian deposition over a landscape. Given the significant impact of fire on aeolian processes in semi-arid deserts, we posit that postfire aeolian redistribution of material is an important control on the spatial variability of …

Hydrogeologic Framework Studies Of Portions Of The Niobrara River, Douglas R. Hallum, Steven S. Sibray, Leslie M. Howard

Conservation and Survey Division

The Nebraska Department of Natural Resources (NeDNR) and Upper Niobrara-White Natural Resources District (UNWNRD) expressed interest in improving understanding and their ability to effectively manage water resources in and around a particular reach of the Niobrara River. Aquifer-thickness contours mapped by the Conservation and Survey Division (CSD) indicate that the principle aquifer has zero thickness in this area. Additionally, the statewide geologic bedrock map produced by CSD shows non-aquifer strata of the White River Group along the same reach, and this setting is consistent with the designation of an “aquifer absent area,” as in the present document. Water-management policy development …

Assessing Ground Penetrating Radar's Ability To Image Subsurface Characteristics Of Icy Debris Fans In Alaska And New Zealand, Robert W. Jacob, Jeffrey M. Trop, R. Craig Kochel

Faculty Journal Articles

Icy debris fans have recently been described as fan shaped depositional landforms associated with (or formed during) deglaciation, however, the subsurface characteristics remain essentially undocumented. We used ground penetrating radar (GPR) to non-invasively investigate the subsurface characteristics of icy debris fans (IDFs) at McCarthy Glacier, Alaska, USA and at La Perouse Glacier, South Island of New Zealand. IDFs are largely unexplored paraglacial landforms in deglaciating alpine regions at the mouths of bedrock catchments between valley glaciers and icecaps. IDFs receive deposits of mainly ice and minor lithic material through different mass-flow processes, chiefly ice avalanche and to a lesser extent …

Depositional Environment And Facies Analyses Of The Owl Mountain Province, Fort Hood Military Installation, Bell And Coryell Counties, Texas, Jacob Meinerts

Electronic Theses and Dissertations

The Owl Mountain Province is a plateaued, karst landscape located in the eastern section of the Fort Hood Military Installation and is characterized by Lower Cretaceous Fredericksburg Group carbonates. The topography is capped by thick sequences of the Edwards limestone; steep scarps and incised valleys along the edges of the plateaus host inter-fingering outcrops of the Edwards and Comanche Peak limestones, and the lower valleys are covered by alluvial sediments and intermittent outcrops of the Walnut Clay. These formations were deposited to the north and west of the main Edwards trend, and are thought to be part of a series …

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 …

Timing And Formation Of Linear Dunes South Of The Niobrara River Valley, North-Central Nebraska Sand Hills, Ashley K. Larsen

Department of Geography: Dissertations, Theses, and Student Research

The Nebraska Sand Hills is a vast (7500 square kilometer) area of grass-stabilized sand dunes. Larger dunes in the Nebraska Sand Hills formed primarily during the Late Pleistocene, but many underwent widespread reactivation during the Holocene. Recent Optically Stimulated Luminescence (OSL) dating indicates that the last major phase of reactivation in the Sand Hills was during the Medieval Warm Period, approximately 800 years ago. Nevertheless, many questions about the evolution of the dunes remain unanswered, particularly regarding the formation of linear dunes in portions of the Sand Hills.

This study seeks to understand more about the formation of linear dunes …