EVALUATING SEDIMENTATION PATTERNS BETWEEN 2014-2017 IN CORAL BAY, ST. JOHN, US VIRGIN ISLANDS:

The 2017 hurricane season battered Coral Bay, St. John, USVI. Recent building of roads and infrastructure has set up St. John for increased sedimentation into Coral Bay, especially during storm events like hurricanes. Previous studies indicated that widespread deposition occurred in the bay due to 2017 hurricanes Irma, Jose, and Maria. This study aims to analyze several sites in Coral Bay, using X-Ray Fluorescence (XRF) to identify differences in elemental concentrations for each site. We used discrete surface samples from each site from 2014 and 2017 to find how these sites have changed temporally and spatially. In addition, we analyzed the mud grain size fraction from 2017 to determine if there was substantial difference in element concentration. Each site was chosen based on available samples and data, as well as proximity and distance to and from possible sources of sedimentation. Interpretation of the XRF data indicated that there was a considerable difference in elemental concentrations between the 2014 and 2017 samples, especially in elements like Sr, Mg, Ca (marine indicators), Ti, Si, Fe, and Al (terrigenous indicators). By normalizing to Ca and Al using ratio analysis, we can identify which sites had a prominent change in terrigenous or marine input. Our data suggest that each site experienced different sedimentation sources due these variations. These findings lead to questions such as where these sources are located, if they are indicative of contaminants, and if they are characteristic of this area, all of which can be addressed with further time and analysis.

Presentation Preference: Poster

Primary Presenter: Prudence Criscuolo, Eckerd College (pcriscuolo@eckerd.edu)

Authors:

Prudence Criscuolo, Eckerd College  (pcriscuolo@eckerd.edu)

Gregg Brooks, Eckerd College  (brooksgr@eckerd.edu)

Rebekka Larson, Eckerd College  (larsonra@eckerd.edu)

Trevor Browning, Elmira College  (tbrowning@elmira.edu)