Post-glacial Environmental History of Acadia National Park and the Search for Rapid Climate Change Events.

Abrupt environmental changes documented in lake sediment records provide evidence that climate is not static, but responds systematically to a variety of forcing mechanisms in sometimes a rapid fashion. Lake sediments serve as archives of environmental changes taking place in a regionally-constrained area and provide a foundation for the reconstruction of climate and vegetation conditions and overall environmental patterns. A 5.5m sediment core was recovered from The Bowl in Acadia National Park and analyzed for loss-on-ignition, fossil pollen, charcoal, and a suite of environmental magnetic parameters. Radiocarbon dating indicates the sediment core spans the entire post-glacial period and was never submerged during the marine incursion. Results from this multi-proxy study suggest The Bowl experienced many of the traditional post-glacial environmental responses including coarse basal sediments reflective of an immature landscape, rapid warming and a shift to a more productive lake system at the conclusion of the Younger Dryas, and a long period of relatively stable environmental conditions supporting growth of the usual vegetation assemblages during the Holocene. Paleoenvironmental reconstructions such as this may provide valuable insight on possible landscape responses to future climate change and serve as theoretical analogs for the types of changes incipient in high latitudes today (e.g. shifting/changing vegetation assemblages).

Microplastics in the Environment

In collaboration with my Environmental Chemistry colleague, Dr. Jim Killarney, we are examining this emerging contaminant in a variety of environmental contexts including marine systems and lake systems. Often overlooked in traditional water quality testing, research has shown microplastics to be a pervasive problem in the environment with potentially detrimental impacts on aquatic life, the extent of which is not fully understood. The ubiquitous nature of microplastics has prompted legislative changes and ensured their place as a widely studied environmental contaminant in the years to come.

Groundwater Contamination

The students enrolled in GL 3044 – Surface and Groundwater Hydrology installed a series of groundwater observation wells and conducted intensive water sampling to evaluate whether or not a series of wastewater settling ponds was leaking. Field surveying and GIS mapping were utilized to model groundwater flow patterns; and chemical concentrations of nicotine, Sudafed, ibuprofen (and others) were used as indicators of wastewater leakage. The results of their field and lab work indicate that there is no leakage from the settling ponds.

Slope Instability

The students enrolled in GL 3223 – Geomorphology installed a series of metal pins and survey targets to evaluate the stability of a hillslope in downtown Unity. The slope and adjacent home exhibit visible signs of slope movement. The purpose of the pins was to establish a baseline surface profile of the hillslope topography and the targets were placed on exposed portions of the house foundation. Laser surveying instruments were used to establish exact positions of these markers to track movements of the slope and house foundation over time.

Environmental Change in Central Maine

The students enrolled in GL 3524 – Lake Sedimentation and Environmental Change collected sediment cores from Lake Winnecook (Unity Pond) for the purpose of reconstructing past environmental conditions around central Maine. Students assume the role of the scientist and are responsible for sediment core retrieval, processing, and analysis. The results of their work include clear evidence of the marine incursion, evolution of vegetation assemblages following retreat of glacial ice, signs of wildfire activity, and more.