Processes controlling the shape and evolution of sandy spits along coastlines

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

Coastal regions are often highly developed, and sustained rates of change of the position of the shoreline can be on the order of meters per year, substantially faster than many other landscape processes that affect human development and infrastructure. Despite a long history of the study of the historic and geologic evolution of these dynamic landforms, it is still not possible to arrive at quantitative prediction of shoreline change. This project will take a major step forward by investigating the controls on the growth and shape of the coastal feature known as a sand spit. These curved accumulations of sand are common features of many coastlines. This project will focus on outer Cape Cod, one of the most recognizable of these features, to conduct field measurements and develop a sophisticated numerical model that documents the evolution of this sand spit. This project will interact directly with the population and decision-makers affected by coastal change by developing a short course and informational materials about coastal processes on Cape Cod and similar settings. This research will investigate how waves affect spit evolution and the sensitivity of spit-headland systems to wave climate changes over both long (millennial) and short (decadal) temporal scales. Quantifying these constraints over historic and geologic time intervals will facilitate a stronger understanding of the evolution of the Cape Cod and Islands region that is applicable to coastal settings over a wide area. The project will use numerical modeling, geologic investigations, and analysis of historic change to 1) identify the controls on spit shape and recurving, 2) investigate how wave climate affects spit development and shoreline evolution, 3) determine patterns of shoreline change in the Cape Cod region over historic (10-100 years), and 4) reconstruct the development of Cape Cod spits over longer (100 - >1000 years) periods.