The grain size of beach sand is one of the crucial determinants of a beach’s slope, and researchers have long known that the finer the sand, the more gradually inclined the beach. However, many New England beaches are typically made up of coarse-grained particles, yet they still slope gradually to the water’s edge. A Northeast CASC supported research team took over 1,000 samples from 18 beaches in Massachusetts and discovered that in the region’s bi-modal (mixed sand and gravel) beaches, it’s only the finer-grained sand that determines a beach’s slope.

The University of Massachusetts Amherst researcher and Northeast CASC affiliate Jon Woodruff who led this work noted, “Understanding how beach sand grain size influences the makeup of our beaches is critical for making projections as to how beaches will respond to storms and sea-level rise”.

This work stems from the Northeast CASC project, “Understanding Sediment Availability to Reduce Tidal Marsh Vulnerability to Sea Level Rise in the Northeast”.