Sapelo Research Application Form
Research Application ID: UGAMI-2024-7 (submitted: 09/18/2024, status: approved)
Project Type: Undergraduate Research (non-REU)
Application Title
Cabretta Island Erosion
Investigator Information
| Principal Investigator: | Robin McLachlan | ||
| Home Institution: | College of Coastal Georgia | ||
| Award Information: | Not funded | ||
| Mailing Address: | 1 College Dr | Phone Number: | 8037077269 |
| E-mail Address: | rmclachlan@ccga.edu | ||
| Brunswick, Georgia 31520-3614 | |||
| Co-investigators: | |||
Project Abstract
Cabretta Beach is part of the Sapelo island Complex in Georgia. From at least 1953 to 2017, the beach eroded persistently due to the southward migration of the inlet separating Cabretta Island from Blackbeard Island to the north. However, Hurricane Irma in 2017 breached the spit of Blackbeard Island and redirected the flow of water. In this study, satellite imagery from Google Earth Pro and Copernicus Browser were analyzed to obtain rates of erosion/accretion pre- and post- inlet breach to determine if and how the altered hydrodynamics affected the vulnerability to Cabretta Beach. Additionally, cross-shore land surveys were conducted on Cabretta Beach to map the presence and migration of beach features that indicate beach stability, including dunes and scarps. An error analysis will be completed to compare the accuracy of field and satellite measurements. Preliminary results indicate that due to the inlet breach in 2017, Cabretta Beach is now in an accretionary part of the inlet breaching cycle. Historic aerial imagery from 1953 shows that the Blackbeard spit was still connected at that time, which indicates that the previous inlet breaching cycle lasted at least 70 years. Therefore, the modern period of accretion on Cabretta Beach is also expected to persist for many decades. The modern accretional beach also has no steep scarp or steep beach slope, meaning it has stabilized. Continued research will expand the scope of this project by examining seasonal storm effects on Cabretta Beach. To accomplish this, repeated field surveys of cross-shore profiles will be conducted to determine the erosion or accretion rates on the beach on monthly timescales.
Project Location
31°26'17.79"N 81°14'15.98"W (North end of Cabretta Beach)
GPS Coordinates for Study Sites
GPS coordinates are listed in the project location field
Expected Start and End Dates of the Project
Start Date: 10/05/2024 End Date: 12/06/2024
Number and Frequency of People Accessing the Site
4 people for 2 days about every month of Fall 2024
Keywords Describing the Project
Equipment Deployed in the Field
No equipment will be deployed.
Plants and Animal Collecting
No
Likely Impacts of the Project on the Site
None, only passive observation
Boardwalk Installation Plans
No
Expected persistence of site impacts after the research is concluded?
No impacts