Presentation on theme: "1 Glaciers Carve Land and Move Sediments Section 5.4."— Presentation transcript:
1 Glaciers Carve Land and Move Sediments Section 5.4
2 Explore Glaciers pg 165 What happened when the ice cube was dragged across the clay? What happened to the sand and gravel in the ice cube as it melted?
3 Extent of Glaciers Glaciers are –In mountain ranges around the world –In land regions at North Pole and South Pole –10% of Earths surface TODAY –Used to be 30% 30,000 years ago
4 2 Types of Glaciers Alpine Glaciers Called valley glaciers Can cause a V shaped mountain valley to become a U shaped valley If an alpine glaciers flows into an ocean, blocks can break off and form an iceberg! Continental Glaciers Called ice sheets Cover Greenland Cover Antarctica
5 2 Types of Glaciers..continued Where do each of the two types of glaciers form? Alpine glaciers form in mountains and flow into valleys. Continental glaciers form on large landmasses (continents) near the poles (North/South).
6 Glacier= large mass of ice that moves over land Alpine Glacier …what are the dark lines? These are rocks picked up by the glacier along its route. Continental Glacier
7 Why are the cracks shown near the surface of the glacier and not at the bottom? At the bottom…. The ice is under so much pressure that it flows instead of cracking….not as much pressure on the top so it cracks.
8 How is an alpine glacier like a plow? The glacier –Scoops up rock and soil –Picks rocks from the sides of valleys –Sediment moves with it
9 Whats left behind? Till= the sediment left on the ground by a retreating glacier. Moraine= a deposit or hill of till AND…….. Moraine at Mono Lake, California, United StatesMono Lake CaliforniaUnited States
10 Whats left behind? Kettle Lakes= bowl depression that was once filled in with ice that has melted after the glacier retreated.
11 Section Review page List 2 processes that cause glaciers to move. –Gravity –Water making the bottom slippery will cause flowing and sliding
12 Section Review page What are the two major types of glaciers and where are they found? –Alpine and found in mountain valleys –Continental and found in Antarctica and Greenland
13 Section Review page Describe the land features left behind by glaciers that have melted and shrunk. –Glaciers leave U-shaped valleys Moraines Abrasions Till Kettle lakes
14 Section Review page Identify two ways in which the erosion effects of glaciers differ from those of rivers. –a. Glaciers crush and move large rocks Rivers move smaller sediments –b. Glaciers pile up moraines, etc Rivers create sandbars, meanders, and deltas
15 Section Review page How would glaciers be affected by changes in climate, such as global warming and global cooling? Warming melts glaciers and shrinks ice sheets (continental glaciers) Cooling causes glaciers to expand and form in new places.
16 Section Review page Regions near the equator are generally the warmest on Earth. However, in one small area of Africa, there are glaciers close to the equator. Form a hypothesis to explain why these glaciers exist.16 IF there are glaciers in Africa near the equator, THEN they are in the high mountains BECAUSE high mountains could be cold enough for glaciers.