National Assessment of Shoreline Change: Historical Shoreline Change along the New England and Mid-Atlantic Coasts
Part of a series of reports on shoreline change produced by the U.S. Geological Survey (USGS), summarizes historical changes of sandy shorelines in 10 regions of the U.S. New England and Mid-Atlantic coasts. The report emphasizes the hazard from erosion at regional scales and relates this hazard to the body of knowledge regarding coastal geology of the New England and Mid-Atlantic region because of its potential impact on natural resources and the economy.
One purpose of this report, and the others in its series, is to develop standard, repeatable methods for mapping and analyzing shoreline movement to allow national shoreline change analyses.
The report summarizes the methods of analysis, interprets the results, provides explanations regarding long-term and short-term trends and rates of change, and describes how different coastal communities are responding to coastal erosion. The report includes additional background information on coastal landforms and historical infrastructure development.
The report had the following findings:
- The average rate of long-term shoreline change for the New England and Mid-Atlantic coasts was -0.5 meters per year with an uncertainty in the long-term trend of ±0.09 meters per year.
- In both the long and short term, the average rates of shoreline change for New England and the Mid-Atlantic were erosional.
- Long-term erosion rates were generally lower in New England than in the Mid-Atlantic. This is a function of the dominant coastal geomorphology; New England has a greater percentage of shore types that tend to erode more slowly.
- However, the percentage of coastline eroding was higher in New England than in the Mid-Atlantic, highlighting that although rates of shoreline erosion may not be extreme, coastal erosion is still widespread along this region of the U.S. coastline.
- The average rate of short-term shoreline change for the New England and Mid-Atlantic coasts was also erosional but the rate of erosion decreased in comparison to long-term rates.
- Of transects used to measure short-term change, 60 percent were erosional, as compared to 65 percent of coast eroding in the long term. The slight decrease (5 percent) in the amount of coastline eroding may be related to an increase in the frequency and extent of nourishment programs and (or) the effects of hardened structures during the more recent time period.
The report's authors conclude that coastal engineering structures along the New England and Mid-Atlantic coasts affect the rates of shoreline change. However, it is difficult to isolate the influence of structures and nourishment projects on the regional long- and short-term rates.
This report is fifth in the series on historical shoreline change. Previous investigations include analyses and descriptive reports of the Gulf of Mexico, the Southeast Atlantic, and, for California, the sandy shoreline and the coastal cliffs. These analyses examine historical shoreline changes along open-ocean sandy shores of the conterminous United States and parts of Hawaii, Alaska, and the Great Lakes.
Publication Date: 2010
Authors or Affiliated Users:
- Cheryl J. Hapke
- Emily A. Himmelstoss
- Meredith G. Kratzmann
- Jeffrey H. List
- E. Robert Thieler