Geomorphology Commons^™

Analysis Of Titan's Fluvial Features Using Numerical Modeling, Jeshurun Horton

Mechanical Engineering Undergraduate Honors Theses

River channels have been observed near the Huygens probe landing site on the surface of Titan, along with evidence of rounded water ice boulders transported through fluid flow. Evidence near the landing site suggests active flow of liquid methane, which has motivated the study of the effects of sediment load and channel sizes on Titan’s fluvial features. A numerical model is used to determine the viscosity, flow velocity, and critical boulder transport diameter based on channel size, slope, and a range of sediment concentrations. This model achieves two ends: first, observed boulder diameters are used to determine the ideal channel …

Ensemble Data Fitting For Bathymetric Models Informed By Nominal Data, Samantha Zambo

Dissertations

Due to the difficulty and expense of collecting bathymetric data, modeling is the primary tool to produce detailed maps of the ocean floor. Current modeling practices typically utilize only one interpolator; the industry standard is splines-in-tension.

In this dissertation we introduce a new nominal-informed ensemble interpolator designed to improve modeling accuracy in regions of sparse data. The method is guided by a priori domain knowledge provided by artificially intelligent classifiers. We recast such geomorphological classifications, such as ‘seamount’ or ‘ridge’, as nominal data which we utilize as foundational shapes in an expanded ordinary least squares regression-based algorithm. To our knowledge …

Diatoms Of The Intertidal Environments Of Willapa Bay, Washington, Usa As A Sea-Level Indicator, Isabel Hong, Benjamin P. Horton, Andrea D. Hawkes, Robert J. O.Donnell Iii, Jason S. Padgett, Tina Dura, Simon E. Engelhart

Geological Sciences Faculty Scholarship

An understanding of the modern relationship between diatom species and elevation is a prerequisite for using fossil diatoms to reconstruct relative sea level (RSL). We described modern diatom distributions from seven transects covering unvegetated subtidal environments to forested uplands from four tidal wetland sites (Smith Creek, Bone River, Niawiakum River, and Naselle River) of Willapa Bay, Washington, USA. We compared our diatom dataset (320 species from 104 samples) to a series of environmental variables (elevation, grain-size, total organic carbon (TOC_SOM), and porewater salinity) using hierarchical clustering and ordination. While no single variable consistently explains variations in diatom assemblages …

Modeling And Measuring Water Level Fluctuations In The Greenland Ice Sheet: How Moulin Life Cycle And Shape Can Inform Us On The Subglacial Drainage System., Celia Trunz

Graduate Theses and Dissertations

In the ablation zone of land terminating sectors of the Greenland Ice Sheet (GrIS), water pressures at the bed control ice motion variability on diurnal and seasonal timescales. During the melt season, large volumes of surface meltwater access the ice-bed interface through moulins.Moulins are large vertical shafts that connect the supraglacial and subglacial drainage systems. Moulins form when a crevasse intersects a surface meltwater source that can drive hydrofracture to the bed of the ice sheet. Upon reaching the bed, meltwater can establish and sustain an efficient, channelized drainage system. Due to the technical impossibility of physically exploring underwater passages …

Linking Human Activities To Water Quality In Coastal New England: Past And Present, Amelia Hurst

University Scholar Projects

This project examines the timing and effect of direct and indirect anthropogenic and natural influences on the marine environment in embayments in southern New England over the past decades to century timescale. We investigated the effects of human land use from colonial through post-industrial times, determined baseline conditions and natural climatic variability, and analyzed the response of marine ecosystems to specific local management actions aimed to improve water quality. A coastal sediment core was taken in Mumford Cove, CT and was analyzed downcore for eutrophication markers (C: N, %C, %N, d¹⁵N, d¹³C) and metals (Hg, Pb, …

Small-Scale Resuspension And Redistribution Of Surface Sediments In The Northeast Gulf Of Mexico, Austin Harris

Master's Theses

Following the release of ~4.9 million barrels of oil into the Gulf of Mexico from the Macondo wellhead, a vast area of the seafloor contained recently deposited marine sediments contaminated by the oil spill. The initial deposition of these contaminated marine sediments was likely not the end of the journey for the particles. Downslope gravitational processes and events of increased current speed in the deep ocean setting can result in recently deposited sediments to resuspend and be moved laterally with the current flow, increasing the area effected by the oil spill. Erosion experiments performed in a closed-loop resuspension flume were …

Hydro-Morphodynamics Of Sandy Coastal Embayments, Shamim Murshid

LSU Doctoral Dissertations

This dissertation investigates the hydro-morphodynamics of two major components of a sandy coastal environment: tidal inlets and embayment shorelines. In the first study, I focused on the evolution of inlet geometry by compiling and analyzing a database with 226 inlets worldwide with a special attention given to their width to depth ratio (or aspect ratio). I found that the aspect ratio has a weak dependency on tidal range and wave height, and they lie in different ranges for three types of tidal inlets: engineered, natural single-thread, and natural compound. I also developed a 2D hydro-morphodynamic model of an idealized barrier-inlet …

Coastal Watershed Monitoring And Management: Geomorphology, Geochemistry, And Hydrologic Modeling Of Los Peñasquitos Creek, Ca, Ravleen Khalsa-Basra

Theses

Rivers in semi-arid climates are directly influenced by local geographic and hydrologic conditions and impacted by modifications to hydrology via urbanization. Changes can influence erosion, morphology, habitat sustainability, and watershed health. In highly urbanized southern California coastal regions, these rare open spaces provide vital ecosystem services. Los Peñasquitos Creek in San Diego County is one such watershed. Using stream surveying and laboratory methods we quantified channel characteristics, grain size distribution, total metal concentration [M], organic carbon (%OC), and phosphate to longitudinally characterize the creek for improved management. Results identified three distinct reaches in the watershed (upper, middle, lower). Downstream, depth …

New Hampshire Continental Shelf Geophysical Database: 2002-2005 Jeffreys Ledge Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Raymond E. Grizzle, Rachel C. Morrison

Data Catalog

Jeffreys Ledge is a major physiographic feature in the western Gulf of Maine (WGOM) located ~50 km off the coast of New Hampshire, although coming within ~10 km of shore by Cape Ann, Massachusetts. Jeffreys Ledge rises up as much as ~150 m from the seafloor of the adjacent basins (i.e., Scantum Basin or Wilkinson Basin) to depths less than 50 m on the ridge surface. The ridge extends over 100 km along its north-northeast to south-southwest axes while generally only being 5 to 10 km in width (~20 km maximum). Jeffreys Ledge and the surrounding region, like many features …

Mapping Michigan's Historic Coastlines, Ryan A. Williams

Dissertations, Master's Theses and Master's Reports

This five-year project, sponsored by the Michigan Department of Environment, Great Lakes, and Energy, is working to map how Michigan’s Great Lakes shorelines have changed over the past 80+ years. Products of this project include publicly available digital, georeferenced, historic aerial photography datasets, as well as map layers depicting the locations of historic shorelines and bluff lines from 1938, 1980, 2009, 2016, 2018, and 2020. Additional products include bluff retreat risk areas, shoreline rate of change map layers, and tools to assist in the development of future Coastal Vulnerability Index projects for the Great Lakes. All products are available as …

Surficial Geology Of The Continental Shelf Off New Hampshire: Morphologic Features And Surficial Sediment, Larry G. Ward, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani, Rachel C. Morrison

Center for Coastal and Ocean Mapping

The continental shelf off New Hampshire (NH) in the Western Gulf of Maine (WGOM) is extremely complex and includes extensive bedrock outcrops, marine-modified glacial deposits, marine-formed shoals, seafloor plains, and associated features that are composed of a range of sediment types from mud to gravel. Furthermore, the physiography and composition of the seafloor frequently changes dramatically over relatively short distances (tens of meters). The complexity of the WGOM seafloor results from the interplay of glaciations, sea-level fluctuations, and marine processes (waves and currents). High-resolution multibeam echosounder (MBES) bathymetry and backscatter surveys, along with ground truth consisting of archived seismic reflection …

Wave Climate Associated With Changing Water Level And Ice Cover In Lake Michigan, Chenfu Huang, Longhuan Zhu, Gangfeng Ma, Guy A. Meadows, Pengfei Xue

Civil & Environmental Engineering Faculty Publications

Detailed knowledge of wave climate change is essential for understanding coastal geomorphological processes, ecosystem resilience, the design of offshore and coastal engineering structures and aquaculture systems. In Lake Michigan, the in-situ wave observations suitable for long-term analysis are limited to two offshore MetOcean buoys. Since this distribution is inadequate to fully represent spatial patterns of wave climate across the lake, a series of high-resolution SWAN model simulations were performed for the analysis of long-term wave climate change for the entirety of Lake Michigan from 1979 to 2020. Model results were validated against observations from two offshore buoys and 16 coastal …

New Hampshire Continental Shelf Geophysical Database: 2012-2013 Newbex Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Zachary S. Mcavoy, Rachel C. Morrison

Data Catalog

An approximately 4.5 km transect running from lower Portsmouth Harbor seaward onto the inner continental shelf was established to serve as the field site for the Newcastle Backscatter Experiment (NEWBEX). Acoustic backscatter measurements were made along the transect to examine relationships between backscatter and seafloor properties. This transect takes advantage of the diversity and heterogeneity of bottom types in lower Portsmouth Harbor and approach. In support of NEWBEX, a field campaign was undertaken to describe the sedimentologic characteristics of the seafloor along the transect. A total of five cruises were carried out approximately seasonally on November 26, 2012 and June …

Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk

Student Publications

The Arizona toad (Anaxyrus microscaphus) and Jones’ waxy dogbane (Cycladenia humilis var. jonesii) are habitat specialists with historical ranges in the desert southwest and specifically, Zion National Park (ZION). The machine learning method, MaxEnt, constructed species distribution models (SDMs) in ZION for the two study species at 30 m and 900 m spatial resolutions using climate, topographic, and remotely sensed data. Additionally, 900 m forecasting models were constructed to observe the shifts in suitable habitat for the years 2050 and 2070, based off two representative concentration pathway scenarios. Results indicate promising predictive power for both high …

The Medium-Term And Event-Scale Tropical Cyclone-Driven Morphodynamics Of A Vulnerable Barrier System With Emphasis On The Role Of Backbarrier Wetlands, Cody Lee Johnson I

LSU Doctoral Dissertations

Coastal mainland barriers and barrier islands provide the first line of defense against oceanic and meteorological forces. Coastal morphological change, which may degrade these barrier's defensive capabilities, occurs over a range of time scales, from geological epochs (>1000 years) to hours and seconds. Coastal morphological change at a vulnerable, but economically strategic, barrier system---the Caminada-Moreau Headlands, Louisiana---is investigated in terms of tropical cyclone impacts and their effects over a 15 year LIDAR survey time series. Analysis of the barrier's three-dimensional morphodynamics at medium-term (decadal) time scales reveals that, while subaerial volume was approximately conserved through time, the impact of …

Cave Airflow Mechanism Of A Crevice-Type Cave: A Case Study From Czechia, Martin Kašing, Jan Lenart

International Journal of Speleology

At present, crevice-type caves are investigated mainly by means of geomorphic and geophysical methods. Microclimatic research of this type of caves is underrepresented and is often limited to temperature and humidity measurement only. Yet, microclimatic research of such caves can significantly help in the management and conservation of caves, speleological exploration or analysis of speleothems. Being the first ever research of ventilation within a crevice-type cave, a complex analysis of cave ventilation was performed within the Velká Ondrášova Cave, a crevice-type cave in the Outer Western Carpathians, Czechia. Long-term temperature recording, airflow tracing within the cave, and a total of …

Effect Of Channelized And Unchannelized Lateral Outflow On Three-Dimensional Flow Structure And Sediment Transport Mechanisms In A River Delta, Mohammad Kifayath Chowdhury

LSU Master's Theses

Spatial and temporal patterns in three-dimensional flow structure have been linked to channel morphology and processes in many environments, including river meander bends, confluences-diffluences, and bedrock canyons. However, there is not yet an understanding of how channelized and gradual, distributed lateral outflows that are often prevalent in deltaic distributary systems influence three-dimensional flow structure and sediment transport mechanisms. This thesis presents an analysis of 3D flow structure data collected from Wax Lake Delta, a naturally developing river-dominated delta in the northern Gulf of Mexico. Three hydrographic surveys were conducted using boat-mounted acoustic Doppler current profiler (ADCP) at two sites: an …

Ecogeomorphic Evolution Of Muddy Coastlines: How Biota On A Range Of Scales, From Microscopic Biofilms To Landscape-Scale Vegetation Zonation Patterns, Interact With Physical Processes, Kendall Cole

LSU Doctoral Dissertations

Coastal wetland ecosystems are inherently interdisciplinary; in these spaces, the physical forces of wind and water meet to interact with stabilizing and fortifying vegetation and biota, as well as mud. The combination of these factors build and sustain wetland ecosystems and without the complex feedbacks, they would cease to exist. In this dissertation, I present three studies that focus on ecogeomorphic interactions within coastal wetlands on a range of scales, from microscopic to the entire landscape and highlight the importance of these interactions when predicting future coastal change. The first study examined how biofilms, matrixes of photosynthetic diatoms and their …

Assessing The Accuracy Of A Uav Snow Depth Survey: Utqiagvik (Barrow), Alaska Calm Grid, Ian Nichols

Dissertations, Master's Theses and Master's Reports

Active layer depth and snow depth are annually collected across the Circumpolar Active Layer Monitoring (CALM) Network to observe the response of the active layer and near-surface permafrost to climate change over decadal-time scales. Snow depth is typically measured using a graduated steel probe at each grid node but, in this paper, we explore the viability of using Unmanned Aerial Vehicle (UAV) (drone) technology to collect snow depth measurements at the 1 km² Utqiagvik (Barrow), Alaska CALM grid. This is achieved by comparing estimated UAV snow depths to measured snow depths collected using a MagnaProbe (MP) at each of …

Response And Recovery Of Horn And Petit Bois Islands, Mississippi, Usa To Tropical Cyclone Impacts: 2004 – 2016, Shara Gremillion

Master's Theses

Horn and Petit Bois islands are two of five Mississippi (MS) barrier islands that provide physical protection from tropical cyclones threatening the MS Gulf Coast, in addition to critical habitat for the northern Gulf of Mexico (GOM). In September 2004, Hurricane Ivan removed a large volume of sediment from the eastern ends of Horn and Petit Bois islands with its 1-2 m storm surge and ~194 kph wind speeds. Then, in August 2005 Hurricane Katrina severely impacted the two islands again with its 3.5-5.5 m storm surge on Horn and Petit Bois islands, and up to 204 kph wind speeds …

Numerical Modeling Of Wave Dynamics And Sediment Transport Near The Mississippi Birdfoot Delta And Barataria Estuary, Soroush Sorourian

LSU Doctoral Dissertations

The Barataria Basin is a large estuarine system in Southeastern Louisiana, connected to the Gulf of Mexico through a number of inlets, the most important of which is the Barataria Pass. This research examines, during April-June 2010 including both cold front passage and calm summer-time wind regimes, the wave dynamics in this basin and in its major inlets, morphological evolution near the Barataria Pass, and the budgeting and dispersal of the Mississippi River sediment in the birdfoot delta region. An unstructured grid, terrain following, high resolution coupled FVCOM-SWAVE-SED model is employed and validated in this study. The numerical model results …

Vulnerability Of Industrial Facilities In The Lower Mississippi River Industrial Corridor To Relative Sea Level Rise And Tropical Cyclone Storm Surge, Joseph Blake Harris

LSU Doctoral Dissertations

Relative sea level rise (RSLR) and tropical cyclone-induced storm surge are major threats to the Lower Mississippi River Industrial Corridor (LMRIC) which has approximately 120 industrial complexes located within the corridor. Spatial interpolation methods were applied to the 2004 National Oceanic and Atmospheric published Technical Report #50 subsidence dataset and cross-validation techniques were used to determine the accuracy of each method. Digital elevation models (DEMs) were created for the years 2025, 2050, and 2075, based on these predictive surface of subsidence rates. Future DEMs were utilized to model RSLR and determine the extent of storm surge on the LMRIC by …

Cave Dripwater Isotopic Signals Related To The Altitudinal Gradient Of Mount-Lebanon: Implication For Speleothem Studies, Carole Nehme, Sophie Verheyden, Fadi H. Nader, Jocelyne Adjizian-Gerard, Dominique Genty, Kevin De Bont, Benedicte Minster, Ghada Salem, David Verstraten, Philippe Clayes

International Journal of Speleology

An important step in paleoclimate reconstructions based on vadose cave carbonate deposits or speleothems is to evaluate the sensitivity of the cave environment and speleothems to regional climate. Accordingly, we studied four caves, located at different altitudes along the western flank of Mount-Lebanon (Eastern Mediterranean). The objectives of this study are to identify the present-day variability in temperature, pCO₂, and water isotopic composition and to assess the possible influence of the altitudinal gradient on cave drip waters and cave streams. We present here an overview of the spatial variability of rainwater based on local and regional data, and …

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 x10 …

Effects Of Natural And Anthropogenic Forcing On Marsh Channel Evolution, Jeremiah Robinson

LSU Master's Theses

Wetlands have many ecological and physical properties that are essential for coastal communities. These ecosystems sustain local economies, provide essential habitats, are a source of numerous ecological and biological services, and protect coastal populations from storms. Of the many wetland types, salt marshes are among the most vulnerable to environmental changes. Salt marshes quickly respond to natural and human-driven perturbations and their high rate of loss in the last century is cause for concern.

In this project the rate of marsh loss driven by channel widening was measured through a comparative analysis of modern high resolution images and historic aerial …

Natural And Anthropogenic Impacts On Sediment Dynamics And Preservation In Contrasting Mississippi Deltaic Coastal Environments, Jiaze Wang

LSU Doctoral Dissertations

Deltas worldwide share the same sinking problem in face of pressure from natural and anthropogenic activities. Many restoration strategies are being planned or have been implemented in the coasts around the world. However, many conventional hard structure constructions are energy-intensive. There are also associated uncertainties and limitations on the effectiveness and sustainability of these restoration plans. Soft or ecological engineering strategies normally take advantage of or mimic the coastal system self-response and feedbacks to natural and anthropogenic activities. The successful implementation of soft strategies relies on process-based studies on the change of complex coastal system. In addition, post-implementation monitoring work …

Persistence Of Stream Restoration With Large Wood, Redwood National And State Parks, California, Diedra L. Rodriguez

Cal Poly Humboldt theses and projects

The conservation and recovery of anadromous salmonids (Oncorhynchus sp.) depend on stream restoration and protection of freshwater habitats. In-stream large wood dictates channel morphology, increases retention of terrestrial inputs such as organic matter, nutrients and sediment, and enhances the quality of fish habitat. Historic land use/land cover changes have resulted in aquatic systems devoid of large wood. Restoration by placement of large wood jams is intended to restore physical and biological processes. An important question for scientists and restoration managers, in addition to the initial effectiveness of restoration, is the persistence and fate of large wood installations. In this …

Internal Composition, Structure, And Hydrological Significance Of Rock Glaciers In The Eastern Cascades, Washington, Adam Riffle

All Master's Theses

Low summer river base flow places a strain on natural and economic resources of the Eastern Cascades. A major contributor to stream flow in this region is snow pack which has declined over the past few decades because of a warming climate. In addition, glacial runoff, which contributes significantly to base flow in summer dry periods, will diminish from glacial recession. However, rock glaciers, because their internal ice (i.e., permafrost) is insulated by an outer debris layer, react slowly to climate change, thus acting as sinks for ice and liquid water storage in mountain environments. This study utilized ground penetrating …

3d Seismic Interpretation Of A Plio-Pleistocene Mass Transport Deposit In The Deepwater Taranaki Basin Of New Zealand, Francisco Jose Rusconi

Graduate Theses and Dissertations

A series of Plio-Pleistocene mass transport deposits (MTD) have been identified in the deepwater Taranaki Basin, in New Zealand, using the Romney 3D seismic survey, which covers an area of approximately 2000 km2. One of these MTDs has been chosen for description and interpretation based on high confidence mapping of its boundary surfaces. The deposit exhibits an array of interesting features similar to those documented by researchers elsewhere plus a unique basal feature unlike those previously observed. The basal shear surface exhibits erosional features such as grooves, “monkey fingers”, and glide tracks. Internally, the MTD is typically characterized by low …

How Dredge Pits Evolve Over Time: A Look At Their Geomorphologic Evolution And Infilling Processes, Patrick Robichaux

LSU Master's Theses

As coastal environments become more susceptible to land loss through accelerating sea level rise and subsidence, new restoration methods harnessing borrowed sediment are more valuable than ever. Mud-capped dredge pits (MCDPs) are a relatively new source of restoration-quality sediment that has only recently been utilized for beach and barrier island restorations in Louisiana. Because MCDPs have been in use for less than two decades in only a handful sites, little is understood about their evolution over decadal timescales. To improve our understanding of MCDPs after they are dredged, we have conducted a suite of geophysical surveys including bathymetry, sidescan sonar, …