Belfast Free Library, Friends of Sears Island, and Belfast Bay Watershed Coalition are hosting a presentation on the history of air pollution in Maine by Dr. Stephen Norton at the library Tuesday, June 5, at 6:30 p.m.

Humans have been able to accurately characterize the chemical climate of Earth for only about 50 years. To study pollution prior to the 1950s, scientists study the archives of pollution that are stored in soils, tree cores, museum collections of vegetation, ice cores from high elevation and/or high latitude, lake sediments, and peat accumulations in bogs.

Dr. Norton’s presentation will focus on what soil surveys and lake and peat sediments can reveal, including a discussion of research done at Sargent Mountain Pond in Acadia National Park, most likely the oldest lake in the state. He will cover other archives as time allows.

Norton is a professor emeritus in the School of Earth and Climate Sciences at the University of Maine. He graduated from Princeton and Harvard universities, earning his PhD in 1967. He joined the Department of Geology faculty at the University of Maine in 1968, where he taught and did research until his retirement in 2008. His research is in the field of aquatic geochemistry.

This event is free and open to the public. For more information, call the library at 338-3884, ext.10. To learn more about Friends of Sears Island check out friendsofsearsisland.org, and visit belfastbaywatershed.org to learn more about the Belfast Bay Watershed Coalition.