How fast can a shoreline change?
Ohio’s Lake Erie shoreline consists of wetlands, low bluffs, and gently sloping shore in the western one-third of the state and glacial till and soft shale bluffs in the eastern two-thirds of the state. The rate of shore erosion is affected by the kind of land and rock materials and the use of protective structures. Use map reading skills to recognize some shoreline features on aerial photos, observe changes in a shoreline over time, and observe the effects of shoreline devices on rates of erosion.
How did rocks and rivers shape the Great Lakes?
The rocks in the Great Lakes Basin are of two main types: metamorphic/igneous and sedimentary. The metamorphic/igneous rocks formed long ago, when molten rock hardened and the heat changed other rocks nearby without melting them. This happened over one billion years ago. The sedimentary rocks in the Great Lakes Basin formed in an ocean that covered most of the basin beginning about 600 million years ago. Use maps skills to relate the hardness of rocks to topography and lake depth, describe the topography of the Great Lakes area, and relate the pre-glacial drainage system to the present size and
position of the Great Lakes.
What causes the shoreline to erode?
Shorelines along the Great Lakes vary in the nature of their sediments and resistance to erosion. Natural causes of erosion include waves, currents, and effects of wind and storms on shoreline processes. Simulate the processes of shoreline erosion to investigate the ongoing changes in coastal areas.