Paper No. 96-42
Presentation Time: 9:00 AM-6:30 PM
AN INVESTIGATION OF ENVIRONMENTAL DISTURBANCES ASSOCIATED WITH HURRICANE HARVEY RECORDED IN CORES COLLECTED FROM CORPUS CHRISTI BAY, TEXAS
Sediment cores are useful for evaluating environmental changes over time, including ecological shifts, metal and nutrient fluxes, and disturbances from catastrophic events such as hurricanes. Hurricane Harvey made landfall along the Gulf Coast on August 25, 2017, as a category 4 tropical cyclone 30 miles northeast of Corpus Christi, TX. Landfall was associated with a significant storm surge and record precipitation that lead to significant flooding. Our purpose is to study two sediment cores collected in June 2018 from Corpus Christi Bay to evaluate the environmental impacts of Hurricane Harvey. To accomplish this analysis, we are evaluating downcore records based on sediment geochemistry, particle size, and diatom assemblages. The two cores were collected in the summer of June 2018 using a HTH gravity corer. The first core was collected off the coast of Corpus Christi Bay in shallow water. The second core was collected further from the shore within the channel where the sediment would be less disturbed by the dredging near the shore. The cores were subsampled in half centimeter increments at Indiana State University and analyzed using portable X-ray fluorescence (pXRF). The downcore geochemical records include unexpected relationships between metals. For example, a strong positive correlation exists between titanium and potassium, while no correlation exists between iron and titanium. The unusual downcore trends may reflect different sources of metals from within the bay as well as from material into Corpus Christi Bay during Hurricane Harvey, or as waters retreated. Ongoing work includes evaluating changes in the physical character of the sediment, such as differences in grain size and organic matter content. Down core variations in particle size and organic matter are explored to see how these may correlate with observed changes in sediment geochemistry and to determine what depth of disturbance is associated with Hurricane Harvey.