Maine's Ever-Changing Beaches

Sea-level rise impacts on coastal archaeological sites: Nathan Hamilton and Rob Sanford, University of Southern Maine
What is the relationship between stability, sea-level rise and archaeology? Coastal erosion coupled with sea-level rise threatens both prehistoric and historic archaeological sites and Holocene landscapes. The archaeology of the Gulf of Maine coast contains a rich and diverse record of human activities adapting to the sea and river mouths. These threatened sites are well known from a protracted interest by natural history and archaeology studies beginning in the mid-nineteenth century. Prehistoric sites often contain shell refuse that preserves bone refuse of birds, fish, mammals and other shellfish species. Currently more than 180 species have been documented from excavated and published sites. With the potential for acceleration of sea-level rise in the coming decades the management of this 5,000-year-old cultural resource must be developed. The management process must evaluate risk and propose conservation measures that are practical in the short and long term. The biological specimens recovered from the archaeological matrix now have realized new potentials to understand the evolution of ecological systems in the Gulf of Maine.

Three ways of tracking change on Maine’s beaches and what they are telling us: Joseph Kelley, University of Maine
Joseph Kelley's Presentation (2 MB)
All visitors to beaches appreciate that beaches are “everchanging.” To a coastal geologist, these changes are recorded in numerous ways in 1) features we see on the beach; 2) structures we observe beneath the beach, and 3) longer time-series of images of beaches. These three scales are covered by more than 25 years of research along the coast as well as numerous photographs taken from the same location over time. What one concludes from an examination of beaches through time is that the appearance of a beach on a given (typically summer) day is representative of conditions that ensued over the previous few days up to two weeks. Larger structures beneath the beach and nearby areas provide a longer timeline, often going back through cycles of erosion and beach growth more than 30 years. Large changes and trends in beach configuration are only apparent over longer time intervals seen in historic maps and air photos.

Session Notes (PDF)