Mapping the Migration Pattern of the Hurricane Harvey Flood Deposit on the Brazos Subaqueous Delta

Hurricane Harvey brought over 100 cm of rain to the lower drainage basin of the Brazos River, resulting in the highest discharge event in the river’s recorded history. The purpose of this project is to delineate the Brazos subaqueous delta flood deposit from Hurricane Harvey, and track its migration pattern. On September 10th, 2017, during the waning phase of the flood, a cruise was scheduled to collect a series of 15 box cores across the nearshore subaqueous Brazos River Delta. Follow up cruises occurred on October 29, 2017 and July 10, 2018 to help track the migration of the flood layer, which aided in the collection of 67 total cores. Observations show that the initial flood layer deposited by Hurricane Harvey averaged on a thickness of 10.5 cm, with the thickest deposit reaching 24.75 cm. Subsequent mapping of the flood layer indicates that after initial deposition, the flood layer has migrated offshore and to the west of its original deposition site. Along with the sediments, organic matter, particle bound contaminants and nutrients are also stored in the storm layer. This layer will potentially be available for re-mobilization due to active shelf processes, which will introduce the nutrients and contaminates to the water column.