Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio

Bibliographic Details
Main Author: Bates, Dustin Thomas
Language:English
Published: University of Akron / OhioLINK 2011
Subjects:
GPR
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=akron1321298181
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-akron13212981812021-08-03T05:26:49Z Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio Bates, Dustin Thomas Geophysical geophysical GPR seismic reflection <p>Urban waterways are important transport pathways, as well as depositional sites for sediments and contaminants. Geophysical methods are one class of techniques that can be used to characterize sediments within urban impacted lake and river systems. A seismic reflection survey was performed in Summit Lake, located in downtown Akron, Ohio. Ground penetrating radar (GPR) surveys were performed in both Summit Lake and the Cuyahoga River Le Fever and Brecksville dam pools, located in Cuyahoga Falls, Ohio and Brecksville, Ohio, respectively. The methods were qualitatively assessed to determine their effectiveness and limitations within these urban settings. Seismic reflection profiles could image the lake bottom in all water depths, except in depths less than 3.6 m deep because transducer ringing overprinted all geologic reflectors. Much of the Summit Lake sediment was charged with methane gas, which completely attenuated the seismic signal and prevented subbottom penetration of the seismic energy. Fortunately, there were areas of less gassy sediment where subbottom penetration was achieved. Sediment cores were collected and the subsurface seismic reflectors were confirmed to correspond to pronounced lithologic changes. GPR surveys conducted from a rubber boat penetrated 3 m or less of lake/river water. The only subbottom signals recorded by the GPR system were point diffractors that were confirmed to be buried logs by probing. From field observations it was evident that there was a relationship between the lake/river bottom reflector amplitudes and the sediment grain size as inferred from probing. Sediment samples ranging from mud to gravel were collected and compared to seismic or GPR data collected at the sample site. The sediment samples were measured for grain size, composition, porosity, organics, density, and P-wave velocity. The amplitude of the lake/river bottom reflector was extracted from the seismic and GPR profiles. Methods were developed to relate lake/river bottom reflection amplitude to sediment grain size. It was found that grain size could be approximated by the lake/river bottom reflector amplitude using both geophysical theory and empirical site-specific relationships from the sediment samples. Seismic and GPR amplitude analysis methods successfully classified all test samples into the correct Wentworth size class (i.e., mud, sand, gravel). However, remotely sensing sediment grain size is limited because seismic reflection and GPR methods were both site and equipment specific. In addition, not all water depths could be imaged by the seismic reflection and GPR equipment.</p><p> GPR surveys performed within the Brecksville Dam pool were also successful in locating and delineating a submerged historic crib dam. Identification of this submerged structure is now being used for the historical assessment component of the Brecksville Dam removal planning process.</p> 2011-12-09 English text University of Akron / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=akron1321298181 http://rave.ohiolink.edu/etdc/view?acc_num=akron1321298181 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Geophysical
geophysical
GPR
seismic reflection
spellingShingle Geophysical
geophysical
GPR
seismic reflection
Bates, Dustin Thomas
Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio
author Bates, Dustin Thomas
author_facet Bates, Dustin Thomas
author_sort Bates, Dustin Thomas
title Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio
title_short Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio
title_full Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio
title_fullStr Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio
title_full_unstemmed Characterizing River and Lake Sediments using Geophysical Methods in Urban Impacted Areas within Summit County Ohio
title_sort characterizing river and lake sediments using geophysical methods in urban impacted areas within summit county ohio
publisher University of Akron / OhioLINK
publishDate 2011
url http://rave.ohiolink.edu/etdc/view?acc_num=akron1321298181
work_keys_str_mv AT batesdustinthomas characterizingriverandlakesedimentsusinggeophysicalmethodsinurbanimpactedareaswithinsummitcountyohio
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