| dc.description.abstract | Hurricane Harvey (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 Harvey, track its migration pattern, and determine the significance extratropical
storm activity has on the remobilization of the deposit. On the September 2017 research
cruise, during the waning phase of the flood, 15 box cores were collected across the
nearshore subaqueous Brazos River Delta. Follow-up cruises occurred in October 2017
and July 2018 to help track the migration of the flood deposit. After observing multiple
characteristics of the cores, results show that the Harvey flood deposit had an average
thickness of 10.5 cm, with the thickest deposit reaching 24.8 cm. A total sediment yield
for Hurricane Harvey of 24.5x106 metric tons was delivered to the GOM by the Brazos
River, where 80% of the sediment was captured by the delta. Subsequent mapping of the
flood deposit indicates that after initial deposition, the flood deposit has migrated
offshore and to the west of its original deposition site, due to a combination of
substantial extratropical storm activity and strong sea breezes between September 2017
and July 2018. Along with the sediment, organic matter, particle-bound contaminants,
and nutrients are also stored in the storm deposit. This deposit will potentially be
available for re-mobilization due to active shelf processes, which can introduce the
nutrients and contaminants to the water column. | en |
