The Characteristics that Control the Stability of Eroding Coastal Bluffs in Maine

Bluffs of glacigenic sediment exist along 53% of the tidal shoreline of Maine. Under the current regime of rising sea level, waves, groundwater, and sub-aerial processes easily erode these materials. The hazardous nature of the bluffs is not widely recognized by the public, and new homeowners are often shocked to find out that their property is disappearing. To better educate the public, the Maine Geological Survey is mapping the stability of coastal bluffs. This report utilizes that database along with other available data to determine what controls the relative stability of bluffs. A geographic information system (GIs) was used to relate the external forcing mechanisms (bluff orientation, exposure, and nature and width of the intertidal zone) and the internal characteristics (degree of human development in the upland, and the surficial geological materials that compose the bluffs) that contribute to erosion of coastal bluffs in the Freeport, ME 7.5\u27 quadrangle