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You searched for +publisher:"University of Akron" +contributor:("Peck, John A."). Showing records 1 – 2 of 2 total matches.

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University of Akron

1. Abebe, Nardos Tilahun. Paleohydrology of West Africa Using Carbonate, Detrital and Diagenetic Minerals of Lake Bosumtwi, Ghana.

Degree: MS, Geology, 2010, University of Akron

The West African monsoon is an important component of the Earth’s atmospheric system because the monsoon redistributes heat and moisture in the tropics. In addition, West Africa is densely populated and has an ecosystem controlled by monsoon rainfall. Therefore, a better understanding of past monsoon variability has social relevance. The hydrologically-closed Lake Bosumtwi occupies a 1.07 Ma meteorite impact crater located in Ghana, West Africa. The lake lies beneath the seasonal passage of the ITCZ; hence, the lake’s sediment record is well suited for studies of past monsoon variability. This thesis research identifies down-core mineralogic variations in a 291-m long sediment core from Lake Bosumtwi using X-Ray diffraction (XRD). Scanning electron microscope and calcium carbonate measurements were also performed to support the XRD results. X-ray diffraction measurements were performed on more than 410 samples at a 1-meter spacing; and at a resolution of 50-cm or less, above 67 m. Lake Bosumtwi mineralogy is shown to provide an interpretable proxy of paleoclimate variability. During several well-documented lake level lowstands (at 3.2 kyr and 16.3 to 20 kyr when the lake was 30 m and 60 m below the present lake level, respectively), increases in calcite, Mg-calcite and total carbonate content indicate carbonate precipitation by evaporative enhancement during arid climate conditions. During the lake-level highstand of the Holocene African Humid Period, calcite is completely absent and Mg-calcite is present in low abundance reflecting the diluted lake water during this moist climate period. In general, detrital (i.e., quartz), carbonate (i.e., calcite, Mg-calcite, ankerite, dolomite) and diagenetic (i.e., analcime) minerals are more abundant during times of low boreal summer insolation when the West Africa summer monsoon is weak. The source of quartz to Lake Bosumtwi include both the bedrock of the crater walls and wind-blown dust from the Sahel, both of which increase during arid periods. Spectral analysis of the quartz record reveals both obliquity and precession periods suggesting that the West African monsoon is influenced by both high and low latitude climate processes. During the last glacial period, pronounced climate events of the North Atlantic (Heinrich events) correspond to increases in calcite, Mg-calcite, aragonite, siderite and quartz. These mineralogic changes are interpreted to reflect arid conditions in West Africa and suggests connection between high and low latitude components of the climate system. Lastly, this research estimated that the variability of mole % MgCO3 in calcite of Lake Bosumtwi sediment can change the d18O isotope signal by about 0.47 to 1.15 ‰. Hence, carbonate mineral variations need to be considered in stable isotope measurements of Lake Bosumtwi sediments. Advisors/Committee Members: Peck, John A. (Advisor).

Subjects/Keywords: Environmental Science; Geology; Mineralogy; Oceanography; Paleohydrology; Paleoclimate; Monsoon; West African; Bosumtwi; XRD; Carbonate; Detrital; Diagenetic; Heinrich Events; Insolation; ITCZ; Obliquity; Precession; Stable Isotope

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APA (6th Edition):

Abebe, N. T. (2010). Paleohydrology of West Africa Using Carbonate, Detrital and Diagenetic Minerals of Lake Bosumtwi, Ghana. (Masters Thesis). University of Akron. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=akron1271102396

Chicago Manual of Style (16th Edition):

Abebe, Nardos Tilahun. “Paleohydrology of West Africa Using Carbonate, Detrital and Diagenetic Minerals of Lake Bosumtwi, Ghana.” 2010. Masters Thesis, University of Akron. Accessed April 24, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1271102396.

MLA Handbook (7th Edition):

Abebe, Nardos Tilahun. “Paleohydrology of West Africa Using Carbonate, Detrital and Diagenetic Minerals of Lake Bosumtwi, Ghana.” 2010. Web. 24 Apr 2019.

Vancouver:

Abebe NT. Paleohydrology of West Africa Using Carbonate, Detrital and Diagenetic Minerals of Lake Bosumtwi, Ghana. [Internet] [Masters thesis]. University of Akron; 2010. [cited 2019 Apr 24]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1271102396.

Council of Science Editors:

Abebe NT. Paleohydrology of West Africa Using Carbonate, Detrital and Diagenetic Minerals of Lake Bosumtwi, Ghana. [Masters Thesis]. University of Akron; 2010. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1271102396

2. Liberatore, Stephen. Changes in Geomorphic Equilibrium on Furnace Run, Summit County, Ohio.

Degree: MS, Geology, 2013, University of Akron

Furnace Run, tributary to the Cuyahoga River, Summit County, Ohio, has experienced pronounced morphologic changes since July 2003. The aim of this study was to examine and interpret present-day and historical geomorphic conditions on Lower Furnace Run in order to explain changes in stream equilibrium conditions. Equilibrium conditions can be altered by changes in land use and precipitation, and this study hypothesizes that climatically-induced changes in precipitation are the leading cause of disequilibrium conditions on Lower Furnace Run. GIS analysis of recent and historical aerial photography, stream gauging, channel mapping, statistical analysis of historical precipitation, discharge, and land cover data, and analysis of climate index data were used to address the hypothesis. Four out of five Cuyahoga River stream gauge stations show a statistically significant increase (a=0.05) in discharge after 2002. Two out of three Northeastern Ohio precipitation gauge stations show a statistically significant increase (a=0.05) after 2002. Non-parametric Pettitt tests reveal an increasing change point in discharge on the Cuyahoga River of February 22/23, 2003, and an increasing change point in precipitation at Hiram, OH on November 6, 2002. GIS analysis of aerial photography reveals Lower Furnace Run increasing in sinuosity from 1.20 in 1981, to 1.34 in 2003, and to 1.62 in 2012. The lateral movement of cutbanks and the area of erosion between aerial photographs were analyzed. The area eroded per aerial photograph time interval is low during the 1980’s (44 m2 mo-1) and mid to late-1990’s (49 m2 mo-1). The area eroded per month increases after 2003 to 255 m2 mo-1 between 2003 and 2005, and peaks at 413 m2 mo-1 between 2010 and 2012. From 1996 to 2006, the area of developed land cover within the Furnace Run watershed increased by 2.2%, and the area of forest cover decreased by 2.4%. Increased development resulted in an increase of 0.5 km2 of impervious surface from 1996 to 2006, which totaled 3.7 km2 in 2006. Major development to install a new highway interchange at the headwaters of Furnace Run was completed in 2001, two years prior to observed geomorphic change in Lower Furnace Run. Prior to 2003, the El-Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) were trending towards positive (dry) phases, and after 2003 ENSO and PDO were trending towards negative (wet) phases, which may have promoted wet conditions within the Cuyahoga River Watershed. Since July 2003, there have been 59 days of extreme discharge, as compared to the 6 days of extreme discharge in the preceding decade.The increase in fluvial energy since July 2003 resulted in a state of disequilibrium on the stream. In order to attain a new state of dynamic equilibrium, the stream responded by accelerating lateral erosion rates to decrease slope, increasing the grain-size of channel sediment, and increasing sediment discharge. The… Advisors/Committee Members: Peck, John A. (Advisor).

Subjects/Keywords: Geology; Geomorphology; geomorphology; geomorphic equilibrium; channel geometry; precipitation; discharge; land cover; climate

University of Akron, was installed in Furnace Run on the downstream side of the towpath bridge on… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Liberatore, S. (2013). Changes in Geomorphic Equilibrium on Furnace Run, Summit County, Ohio. (Masters Thesis). University of Akron. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=akron1365872441

Chicago Manual of Style (16th Edition):

Liberatore, Stephen. “Changes in Geomorphic Equilibrium on Furnace Run, Summit County, Ohio.” 2013. Masters Thesis, University of Akron. Accessed April 24, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1365872441.

MLA Handbook (7th Edition):

Liberatore, Stephen. “Changes in Geomorphic Equilibrium on Furnace Run, Summit County, Ohio.” 2013. Web. 24 Apr 2019.

Vancouver:

Liberatore S. Changes in Geomorphic Equilibrium on Furnace Run, Summit County, Ohio. [Internet] [Masters thesis]. University of Akron; 2013. [cited 2019 Apr 24]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1365872441.

Council of Science Editors:

Liberatore S. Changes in Geomorphic Equilibrium on Furnace Run, Summit County, Ohio. [Masters Thesis]. University of Akron; 2013. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1365872441

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