Dataset: Sediment properties collected off the Alabama coast before and after Hurricane Sally, 2020-2021

Sediment cores (9.6 cm inner diameter) were collected with an Ocean Instruments MC-400 multicorer or via SCUBA diving at each site and timepoint. Grain size was measured in the top 8-12 cm of sediment. 1-2 cores were sectioned into 1 cm increments and dried at 65 °C for 48 h. Dried samples were placed in a muffle furnace at 550 °C for 4 h to combust sediment organic matter. Porosity and organic content were calculated from the sediment mass differences before and after drying and combusting, respectively. Combusted sediment was then placed in a 1% sodium hexametaphosphate solution for at least 3 weeks to deflocculate. After weeks of deflocculating, clumps of mud often remained intact in muddier samples, so all samples were gently rubbed with a gloved finger on a 63 μm sieve to break up mud clumps. The mud was then washed through the sieve and combined with the sand retained on the sieve. After breaking up clumps, we measured grain size distribution using a Malvern Mastersizer 3000. For each sample, 5 measurements were averaged and then analyzed using Gradistat (Kenneth Pye Associates, LTD.).

Bottom water salinity and temperature (° C) measured at each site and timepoint using a CTD (conductivity, temperature, depth) instrument array.