Physical Sciences and Mathematics Commons^™

Using Camera-Monitored Sediment Traps To Evaluate Sediment Availability And The Role Of Waves In Resuspending Seafloor Sediment, Bellingham Bay, Wa, Liam Horner

WWU Graduate School Collection

Understanding nearshore sediment budgets and processes is important for evaluating coastal hazards, habitats, and contaminant fate to enable informed decisions in coastal planning and management. I aimed to evaluate the role of waves in resuspending and redistributing sediments and by proxy contaminants in the urban/estuarine Bellingham Bay, and better understand the transport and rate of fluvial sediment moving through the nearshore. I integrated analyses using camera-mounted sediment traps, seafloor grain-size data, short-lived radioisotopes, and other fluvial, physical oceanographic, and wind data. I paired cameras with sediment traps, to identify the timing and rate of sedimentation on the seafloor at hourly …

Fine Grained Delta Front Sediment Transport, Sarah Noel

University of New Orleans Theses and Dissertations

Insights into transformative coastal processes are unlocked though understanding sediment transport mechanisms in fine-grained delta front environments. Movement of fine-grained sediments on delta fronts is not wholly explained through advection settling models. While advection settling models generally assume deposition into a still body, numerical modeling of sediment re-entrainment suggests there may be tidal, wave, and/or non-steady hydrograph influences allowing particles to reach greater distances by altering the decelerating velocity field. This research explores both an advection settling model and a mass conservation Rouse profile model to understand the irreducible delta front processes controlling sediment deposition. Using field data collected on …

Assessing The Anthropogenic Footprint On The Channel Sinuosity Of The Rio Grande The Delta, Edoardo Davila

Theses and Dissertations

The Rio Grande has been an emblematic feature and a source of life for the Rio Grande Valley. Since Pre-Historic times, it has provided the resources that allowed communities to thrive in a land where water is scarce. Large scale anthropogenic activities including, primarily in the form of river diversions and dam construction, have negatively impacted the river. Twenty-three major dams, and many small ones built on the main channel and many of its tributaries in the last century, have drastically reduced water discharge and virtually eliminated sediment delivery to the delta. This study explores how the channel sinuosity …

Modeling The Lafourche Delta Network In The Mississippi Delta Complex, Byong-Suk Chun

Graduate Theses and Dissertations

The distributary channel network morphology on deltas is important for the delta evolution study because channels are the primary conduit for carrying and distributing water, sediment, and nutrients to the coast. Numerical models of river deltas and their channels have improved remarkably over the past two decades. However, the long-term (millennial scale) simulation of real delta systems remains rare. Here, we attempt to reconstruct the Lafourche Delta channel network, active 1600-600 years before present, with a simple numerical model (Moving Boundary Model for Distributary Network, MB_DCN). The model was run for 9 possible paleo basin boundaries and 6 water discharge …

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 …

Persistence Of Depositional Features In A Strongly Seasonal, Tide-Dominated Delta, Kallie Flaxington Brown

OES Theses and Dissertations

The Ganges-Brahmaputra-Meghna (GBM) Delta is one of the largest deltas in the world, covering more than 100,000 km². The GBM River system transports over one billion tons of sediment annually and delivers ~750 million tons to the Bay of Bengal, ~25% of which is advected by tides into the fluvially abandoned western delta plain. The Sundarbans National Forest (SNF) is located within the GBM Delta and, covering more than 10,000 km², is the world’s largest continuous mangrove stand. The present rate of sediment delivery allows the SNF platform elevation to keep pace with regional sea level …

Keeping Pace With Relative Sea Level Rise: Marsh Platform Monitoring Shows Minimal Sediment Deficit Along The Louisiana Coast, Kelly Marie Sanks

Graduate Theses and Dissertations

Recent reports estimate that the marshes of the Mississippi Delta receive just 30% of the sediment necessary to sustain current land area1. An extensive monitoring campaign by the USGS and LCPRA provides direct measurements of sediment accumulation, subsidence rates, and deposit characteristics along the coast over the past 10 years2, allowing us to directly evaluate this sediment balance. By interpolating bulk density, organic fraction, and vertical accretion rates from 273 sites, a direct measurement of organic and inorganic sediment accumulation can be made. Results show that a total of 82 MT/year of sediment is delivered to the coast. Using a …

3d Seismic Analysis And Characterization Of A Stacked Turbidite Channel: Niger Delta Complex, Anthony Luna

Master's Theses

A stacked turbidite channel was interpreted from 3D seismic data acquired in the Niger Delta off the west coast of Africa. In offshore environments, such as the Niger Delta, submarine canyons provide a conduit for currents to transport large sediment loads to form stacked turbidites. Turbidite channels are typically convoluted deposits and contain sands that are potential reservoir targets of hydrocarbon exploration. The internal characteristics of these turbidites are often complex and difficult to interpret accurately. This study characterizes the morphology of a stacked turbidite deposit by describing key features that are commonly found in turbidite channels, including: channel sinuosity, …

A Subsurface Stratigraphic Study Of The Middle Atoka, Sebastian County, Arkansas, Sara Beth Sutton

Graduate Theses and Dissertations

Raster log images were analyzed to study the subsurface stratigraphy of the Middle Atoka in the Arkoma Basin of the western portion (Sebastian County) of Arkansas. The most significant sandstone units of the Middle Atoka in this area were determined to be two generally coarsening-upward sequences in the lower portion of the formation. Based on lithologic correlations, these two units were determined to be the informally named Casey and Freiburg members of the Middle Atoka. Thickness information based on picked tops was used to create isopach maps of the units of interest. The log signatures and geometry of the sand …

An Evaluation Of The History Of Aqueous Activity On Mars Through A Survey Of Select Hypothesized Martian Deltas And Paleolakes Via The Analysis Of Mineralogy, Morphology, And Thermophysical Properties, Andrea C.G. Hughes

Masters Theses

Aqueous deposits are an essential key to understanding the geologic/climatic history of water on Mars. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), High Resolution Imaging Science Experiment (HiRISE), and Thermal Emission Imaging System (THEMIS) have enabled studies of Martian fan deposits in unprecedented detail, including the identification of hydrated minerals (such as phyllosilicates, carbonates, and sulfates) and morphologies consistent with formation in an aqueous environment associated with Martian sedimentary deposits. In this study, twenty-six previously identified fan-shaped deposits (hypothesized as possible deltas) have been examined for hydrated minerals in the beds and distal regions of the deposits. Six deposits …

Sediment Flux Through The Rio Grande River: A Monsoonal Effect, Troy C. Hiatt

Theses and Dissertations

Climate has historically been recognized as an influence on sediment flux and deposition. The North American Monsoon is suggested as the forcing mechanism of deltaic progradational events of the Rio Grande River delta. Interpretations of reflection seismic profiles reveal that eustatic rise in sea-level from the Last Glacial Maximum to present is accompanied by several regressional events of the Rio Grande delta 5.5, 9.5, and 11.5 ka BP. Much of the migration of depositional facies within a delta system is forced by hinterland tectonics and base-level rise and fall. However, we suggest that the movement of facies within the Rio …

Palynological Analysis Of Tiger And Trinity Shoals, Louisiana Continental Shelf, Russell Ryan Crouch

LSU Master's Theses

Forty sediment samples taken from twenty-six vibracores collected from Holocene shoals (Tiger and Trinity) were processed for palynomorphs and analyzed to characterize the terrestrial and marine paleo-environments of southern Louisiana at the time of deposition of each shoal. Abundant and diverse pollen assemblages were recovered while marine microplankton were sparse (< 2% relative abundance). Pollen species were grouped by plants of similar environmental significances including arboreal, non-arboreal, aquatic, and shrub categories. Palynological signals were compared in detail between each core, as well as along strike and dip transects, to help determine whether or not these shoals were deposited coevally or in distinct depositional cycles. Evidence shows that Tiger and Trinity Shoals carry remarkably similar palynological profiles, indicating that sediments of these shoals areS from the same source, and that deposition extended over an interval of time such that climate change was not sufficient enough to alter the vegetation response (hence palynological signal). Pollen profiles show source sediments are predominantly from the lower Mississippi River drainage basin and exhibit species similar to those present in modern Louisiana coastal marshes and swamps (i.e., Taxodium distichum, Cyperaceae, Graminae, Chenopodiaceae, and Asteraceae), and coastal to upland hardwood forests of the Mississippi River alluvial valley (i.e., Pinus, Quercus, Carya, and Liquidambar styraciflua).

Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Red Pine Shale (RPS; ~1120m thick), uppermost formation of the Neoproterozoic Uinta Mountain Group, Utah, is an organic-rich sedimentary succession interpreted as a marine deltaic system that delivered immature sediment from the north that mixed with mature sediment from the east. Multiple data sets suggest regional climate and sea-level changes associated with changing organic-carbon burial rates.

Six facies were identified and represent wave-, tidal-, and river-influenced parts of the distal prodelta to delta front in a marine system. These include the shale facies and associated concretion facies (distal prodelta), the shale-sandstone facies (proximal prodelta to delta front), the slump …

Significance Of Variations Among Ancient Deltaic Deposits In The Arkoma Basin, North-Central Arkansas, Christine Michelle Wright

LSU Master's Theses

The Arkoma Basin is one of several foreland basins formed in association with the Ouachita orogeny. The Arkoma Basin has been studied in depth with regard to stratigraphy, depositional environments, structure and its relationship to the Appalachian-Ouachita orogenic event. This study focuses on the variability of the deltaic deposits within the Arkoma Basin and the significance of the variables to both the delta complex and the overall tectonic setting. The specific characteristics to be investigated include variations in paleocurrent directions, bed thicknesses, bed geometries, organic contents, sand/shale ratios, mineral assemblages and fossil assemblages. In the case of the Arkoma deltaic …

Distributary Mouth Bar Formation And Channel Bifurcation In The Wax Lake Delta, Atchafalaya Bay, Louisiana, Anton J. Dumars

LSU Master's Theses

The Mississippi River has undergone at least seven cyclic avulsions during the Holocene epoch. The latest avulsion, down the Atchafalaya River into the Gulf of Mexico, has produced two bayhead deltas prograding into Atchafalaya Bay. The Wax Lake Delta, typical of other Mississippi sub-deltas, has a natural anastomosing channel pattern. In contrast, the Atchafalaya Delta, situated in the eastern side of the Bay, has experienced sporadic and limited growth due to the dredging of a navigation channel below natural depth. Channel bifurcation, and sediment transport processes and responses, were investigated in the Wax Lake Delta, using channel flow velocities, suspended …