Interpreting sediment transport pathways: an investigation of Hurricane Ike's impact on Offatt's Bayou, Texas

Abstract

Hurricane Ike made landfall near Galveston, TX with a 3-4m storm surge, inundating the surrounding area. The purpose of this study was to determine the existence or absence of a sedimentary deposit produced by Hurricane Ike within Offatts Bayou, the largest embayment within Galveston Island. Sediment samples were retrieved from the area of study using gravity core and bottom-grab sampling devices. These samples were then analyzed for water-content, grain size, and 210Pb geochronology. A Teledyne Benthos C3D high-resolution side-scan sonar and bathymetric system was implemented to collect sonar data reflecting the bathymetry and surface sediment features and composition of the study area. Analysis of remote sensing imagery recorded immediately after the Hurricane indicated a northeasterly flow pattern suggesting a predictable deposition in the north east portion of the bayou. Evidence of this deposit is supported by a backscatter anomaly observed in the side-scan sonar mosaic and coarse grained sediment feature indicated by grain size analysis. The study highlights erosion patterns experienced by developed coastal areas during brief periods of high energy associated with storm activity