Quaternary Coasts of the United States: Marine and Lacustrine Systems

Quaternary Coasts of the United States: Marine and Lacustrine Systems Project #274 Quaternary Coastal Evolution - This Special Publication represents the major cumulative contribution of the Working Group of the United States of America to IGCP Project 274. The primary aims of Project 274 are to: (1) document and explain local to global variations in coastal and continental-shelf evolution, incorporating knowledge of coastal and shelf processes and environment with geodynamic, climatic, oceanographic and other data to produce local and regional models, ranging from descriptive to numerical, leading to a better understanding of interactive forces responsible for past, present and future changes to the coasts of the world; and (2) promote specified thematic studies, which are necessary to solve problems of coastal change affecting human occupation of the coastal zone. The volume contains sections on Atlantic, Pacific, Gulf and Lacustrine shorelines, covering both Holocene and Pleistocene deposits, representing a summary of decades of research into coastal and continental-shelf evolution of North America.
Erosion of the United States Shoreline
-
Published:January 01, 1992
Abstract
Over 75 percent of the United States ocean shoreline is eroding retreating landward Shoreline progradation where occurring is generally assumed to be a temporary phenomenon When affecting a developed area shoreline retreat is usually termed erosion but considerable confusion remains over the use of this term Retreat and progradation refer to achange in shoreline position whereas erosion and accretion refer to volumetric changes in the subaerial beach As used in this paper however erosion refers to any form of shoreline retreat consistent with common usage.
Coastal erosion is a fundamental and widespread process on U S and world shorelines Evidence particularly on barrier island coasts indicates that in the past few decades or millenia erosion may have become a more widespread process Possible causes of this change include the effect of humans shoreface steepening or an increase in the rate of eustatic sea level rise.
Mechanisms responsible for shoreline erosion are highly variable both temporally and geographically. In addition, our understanding of shoreline sediment transport dynamics is incomplete. Consequently, we are presently unable to predict accurately future shoreline-retreat rates related to continued sea-level rise. The Bruun Rule, for example, predicts little shoreline retreat relative to using, as a predictive tool, the slope of the land surface over which sea level is expected to rise.