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Beach and Dune Profiles:
An Educational Tool for Observing and Comparing Dynamic Coastal Environments
January 2001

(Click here to view this document as a PDF file.)

Beaches and dunes are in constant motion, continually changing shape and shifting position in response to winds, waves, tides, relative sea level, and human activities. The most significant changes occur seasonally and following storms. During summer, beaches are generally higher and sandier than they are in winter. During the winter, the ‘missing’ sand moves from the beach to nearshore areas to form sandbars. This happens as a result of changing wave shape due to more intense storm activity. During spring and early summer, or following a storm, the sand in the nearshore region moves back toward -- and eventually attaches to -- the beach. Once on the beach, the finer sand grains are moved by wind action to form higher, wider sand dunes. These seasonal and storm-related interactions and changes in the form, volume, and position of beaches, dunes, and nearshore areas produce what is known as ‘dynamic equilibrium’ (Figure A, below).

Beach and dune profiling is one way to obtain information about seasonal and storm-induced beach and dune shapes. Comparing season-to-season profiles and profiles taken before and after a significant storm clearly illustrates the important changes taking place along the shoreline and how quickly coastal landforms change.

There are several methods for obtaining beach and dune profiles, and each has its advantages and disadvantages. The U.S. Army Corps of Engineers has published descriptions of each method (see references). One of the simplest, rapid, and inexpensive methods is known as the Emery Rod Method, named for a former Woods Hole Oceanographic Institution (WHOI) geologist, Kenneth “K.O.” Emery.

Emery Rod Construction

Emery Rod construction is quite simple. Necessary components include four wooden rods, each 1-inch square and 5 feet in length. Two rods are painted one side only with alternating bright colors (such as red and white), with each block painted in increments of tenths of feet, or in inches or centimeters, beginning at the top. The remaining two rods are connected to the painted rods (with bolts and wingnuts) to form a parallelogram (Figure B, p. 2).

NOTE: To prevent the rods from sinking into the sand and thus giving inaccurate elevation readings, it is recommended that ‘foot pads,’ made of small discs of wood or large bottle caps, be attached to the bottom of the two vertical rods.