Grand Strand Geology and its impact on Beach Nourishment
Lower-level oceanography course; could be augmented for upper-level classes in stratigraphy, coastal processes/environments, or the geology of the Coastal Plain.
Skills and concepts that students must have mastered
Very basic sedimentology
How the activity is situated in the course
Content/concepts goals for this activity
Interpretation of nature of geologic setting of this section of coast.
Back-of-envelope calculation of available sand
Higher order thinking skills goals for this activity
Societal impact of beach replenishment and available sand supply
Other skills goals for this activity
Description and Teaching Materials
Students use USGS Fact Sheet 2005-3041 for this investigation. See References and Resources below for full reference and URL.
The Fact Sheet includes a geologic map of the coastal area and near offshore, sidescan sonar image of the near offshore (to a water depth of 14 m), geologic cross-section along the coast, seismic profile across an inlet, and map of estimated offshore Holocene sediment thickness.
The activity leads students through analysis of the basic geologic setting and interpretation of the meaning of the sidescan sonar and other datasets. Through this, they see that much of the Grand Strand coast is pre-Holocene material (and Pliocene fossils, including large shark teeth, wash up on the beach during storms from offshore outcrops). While the Fact Sheet identifies an offshore sand body apparently suitable for beach replenishment, simple calculations show that the volume is not large relative to likely need. This limits its practicality for long-term re-nourishment.
Student Handout for Grand Strand (Microsoft Word 33kB May30 14)
Solution Set Grand Strand (Microsoft Word 36kB May30 14)
Teaching Notes and Tips
References and Resources
Jane F. Denny, Wayne E. Baldwin, William C. Schwab, John C. Warner, M. Richard DeVoe, 2005, South Carolina Coastal Erosion Study: USGS Fact Sheet 2005-3041, 4 p. available from http://pubs.usgs.gov/fs/2005/3041/Broader stratigraphic context can be found in a strike section of the North Carolina Coastal Plain (Figure 1-3) of
Farley, M.B., Phillips, P.L., and McBroom, R., 2007, Investigating Regional Hydrogeology of the Mid-Atlantic Coastal Plain: http://serc.carleton.edu/introgeo/icbl/examples/19297.html