Effects of Extreme Storms on Diagenesis and Recycling of Silica in the Mississippi Delta.
The effects of Hurricanes and other non-steady events on silica cycling and storage in marine sediments is understudied. This study measured grain size distributions, excess Lead-210, and porewater [dSi] on sediment and porewater samples from before and after Hurricane Ida. Diffusive fluxes of dSi across the sediment water interface were also calculated.Ìý
We found a dramatic change in Excess Lead-210 distributions, along with an increase in coarser grain sizes, in the aftermath of the storm event, indicating sediment redistribution. Porewater [dSi] increased from 520 µM up to 823µM after landfall and remained elevated above pre-storm values for the following year after the storm. Diffusive fluxes of dSi were calculated to be between 0.563 ± 0.035 to 2.601 ± 0.010 mMol m-2 day-1 in the aftermath of a storm. The results suggest that hurricanes are a previously under-appreciated source of dSi to the global coastal ocean.