Floodplain Management SESSION 3 Stream Systems on Dynamic Earth Glaciation & Erosion Processes Prepared By Donald R. Reichmuth, PhD.

Glacial & Erosion Framework Objectives: Glacial conditions in North America for the last 30,000 years affect river basins and floodplains Rates and processes of erosion, transport, and deposition The production and movement of sediment by the agents/processes of erosion -- water, ice, gravity, and wind Case study team assignments

Glaciation & Surface Processes Glaciation Alpine Glaciers Continental Glaciers Geomorphology Surface Forming Processes –Water –Ice –Gravity –Wind

Northern Hemispheric Glacial Areas 16,000 B.P. NOTE: Portions Of Alaska Are Ice Free

Pleistocene Glaciation Note: Alpine Glaciers Continental Glaciers Ice Marginal Rivers Alaska Ice Free Area

Glacial Impact Areas

Preglacial Teays Basin Teays Basin Overrun By Ice Channel Buried Ohio River Forms Drains Basin

Western Glacial Lakes 15,000 B.P. –Climate Much Wetter Than Present –Large Basins Had Internal Drainage

Loess Wind Blown Silt From Glaciers Rock Flour Stream Banks Stand Vertical When Stable

Glacial Rebound Contours In Meters Uplift

Great Lakes Glacial Rebound Contours – Uplift per 100 Yrs.

Sea Level Changes 16,000 Years BP Meters Lower 6,000 Years BP – Reached Present Level Near Future – Expected To Rise

Holocene Sea Level Changes Primary Cause --- Glacial Melting In The Northern Hemisphere

Erosion In River Basins Controlling Factors: Chemical vs. Mechanical Weathering –Temperature –Precipitation Basin Gradient Basin Soil/Bedrock Type Tectonic Activity

Chemical & Mechanical Weathering

Erosion Processes

Mass Movements

Class Handout

Slide Presentation Prepared By Geomax, P.C. Dr. Donald R. Reichmuth, President 1023 W. 30 th Ave. Spokane, WA Phone & FAX – –