For the Instructor

These student materials complement the Coastal Processes, Hazards and Society Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.

Initial Publication Date: December 7, 2016

Indirect Effects on Coasts by Glaciation

The indirect effects of glaciations are considered to be associated with the lowering of sea level during the last Ice Age and the subsequent rise of sea level that coincided with the melting of the ice-age ice sheets and glaciers. During the period of major ice sheet and glacial expansion, sea level was approximately 120 meters lower then it currently is today. During this period of lowered sea level, rivers systems on a global extent would have extended across the continental shelves, which were subaerially exposed because of the lowered sea level. River valleys cut across the continental shelves as rivers flowed across the continental shelves to reach the new elevation of sea level. The valleys were progressively widened and deepened, and during deglaciation melt, water was released back into the ocean basins and sea level progressively rose so that the river valleys became inundated. This indirect process of glacial and ice sheet influence on the coastal zone is evident in Chesapeake Bay of the eastern United States. The Chesapeake Bay, as well as many other drowned river valleys, provide critical habitat for freshwater, brackish, and marine water species of plants and animals, but are becoming a progressively more endangered habitat because of influx of agricultural nutrients through runoff and discharge of wastewater into these environments.