Date of Award

12-2014

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Earth Sciences

Advisor

Daniel F. Belknap

Second Committee Member

Joseph T. Kelley

Third Committee Member

Stephen M. Dickson

Abstract

Landslides on the Maine coast occur frequently in areas underlain by Presumpscot Formation glaciomarine sediments. They are usually progressive rotational failures (slumps) in areas of thick glaciomarine sediment exposed at coastal bluffs. They range in size from a few hundred m2 in many locations to greater than 1.4 hectares (3.5 acres), such as the Rockland harbor slumps of 1973 and 1996. There appears to be a rough inverse correlation between slump size and frequency of occurrence (yearly to several decades). Slumps and landslides can cause property damage in the hundreds of thousands of dollars, and have the potential to damage important public infrastructure such as roads, sewer lines, power and water supplies. Widespread bluffs of Presumpscot Fm. within many estuaries and bays of the southern and central Maine coast undergo a cycle of weakening at incipient cracks, slumping, stabilization by salt marshes on the slumped sediment platform, and then renewed steepening through bluff erosion. Similar slumps are also found in the interior of the state in areas underlain by the Presumpscot Fm. We use ground-penetrating radar (GPR) and LiDAR imagery to characterize historic and ongoing slumps, and to define areas of potential future failures. This allows us to better inform the public of the risks associated with unstable coastal bluffs and identify specific slump hazard potentials.

Files over 10MB may be slow to open. For best results, right-click and select "save as..."

Share