DISAPPEARING SEDIMENTS: AN EFFECT OF CLIMATE CHANGE TO MASSACHUSETTS’ BEACHES

Research for this study began in the summer of 2009 with the intent to gather data each subsequent summer, determining the effects of climate change on the grain size distribution of Massachusetts’ beaches. A contributing factor to coarsening beaches is the increase in storm activity which is predicted to become more frequent in the future (Webster et al, 2006; Meehl et al, 2000). Storms erode fine grains from beaches and deposit them offshore leaving larger, heavier grains on the beaches (USGS, 2009).

The focus of this study was on seventeen sites, both north and south of Boston, MA including barrier islands and exposed mainland coasts. Sites varied in coastal development, from beaches with mostly intact dunal and lagoonal systems to those redesigned with seawalls, jetties, and other constructions. Samples were taken from June through August of 2009, 2010, and 2012 from the same locations, determined using a GPS. In the lab, these samples were sorted for grain size distribution. This data has been compiled to show changes caused by erosion at these sites over time. This data set was analyzed for the expected coarsening. The results showed a very dynamic picture of Massachusetts’ beaches from 2009 to 2012.

References

Meehl, Gerald A., Francis Zwiers, Jenni Evans, Thomas Knutson, Linda Mearns, & Peter Whetton. (2000, March). Trends in Extreme Weather and Climate Events: Issues Related to modeling Extremes in Projections of Future Climate Change. Bulletin of the American Meteorological Society, 81(3), 427-436.Tarbuck

USGS. (2009, October). Coastal change hazards: hurricanes and extreme storms. Retrieved December 8, 2009 from http://coastal.er.usgs.gov/hurricanes/coastal-change/beach-erosion.html

Webster, P.J.; G.J.Holland; J.A. Curry; H.R. Chang. (2006, September 16). Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment. Science. 309(5742). 1844-1846.