Initial deposition and offshore migration of the Hurricane Harvey Flood Layer across the Brazos River subaqueous delta and shelf-Gulf of Mexico-the largest recorded discharge event for the Brazos River

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 recorded history of the river. The purpose of this project is to delineate the Brazos subaqueous delta flood deposit from Hurricane Harvey, and compare it to past flood deposits of the Brazos River. 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. A follow up cruises occurred on October 29, 2017 and July 10, 2018 to track the migration of the flood layer.. Preliminary results have found that Hurricane Harvey deposited a flood layer averaging 30 cm thick, which is about 5 times larger than the annual sediment layer that is deposited and subsequent mapping of the flood layer indicates that after initial deposition, that 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 and are potentially available for remobilization due to active shelf processes and results of some of these analyses will also be reported.