1. Glaciers Pg. 61

2. Moving masses of ice • Glacier- large moving mass of ice • Form near earth’s poles • Cover about 10% of Earth • In places like Greenland, temps never get warm enough to melt all the snow • The snow accumulates in areas called snowfields • Keeps growing until a glacier forms • Classified as either valley or continental glaciers

3. Valley Glaciers • Form in valleys in high mountainous regions • Begins to move when it becomes too large (exceeds 20 m thickness) • Carves v shaped valleys into u shaped valleys

4. Continental Glaciers • Cover broad areas • Thickest at the center • Also called ice sheets • Confined to Greenland, northern Canada, and Antarctica

5. Glacial Erosion • Most powerful agent of erosion • Breaks off pieces of rock, called plucking • Rocks attach to the side of glaciers and aid in erosion • Small scratches called striations; large called grooves (provide glacial history) • Carve deep depressions called cirques • Where 2 cirques meet, a steep ridge called an arete forms • Friction determines rate of flow

6. Glacial Deposition • Mixed debris that glaciers carry is called glacial till • Ridges containing till deposits are called moraines • Sometimes they form lakes called kettle lakes • The great lakes are formed from moraine-damned valleys

7. Pg. 62 • Complete the science and math activity and attach it as a flap to page 60. • Be sure to answer all questions • Use a sticky note graph paper for number 2 under the Challenge section