Warm-up:

1. Warm-up: Set-up Cornell Notes: • How are glaciers related to global warming? • What do we need to know about glaciers to answer the question? This is our essential question These are our left side questions

2. What is a glacier?

3. Glaciers A glacier is defined as a thick mass of ice that forms over land from the compaction and recrystallization of snow, and shows evidence of past or present flow. Glaciers are part of both the hydrologic cycle and the rock cycle.

4. What is NOT a glacier? • Is there more than one kind of glacier?

5. Types of Glaciers Valley, or alpine glaciers form in mountainous areas

6. Types of Glaciers Ice sheets, or continental glaciers, are very large. They are masses of ice covering more than 50 000 km². For example, ice sheets cover Greenland and Antarctica.

7. The only present-day continental ice sheets are those covering Greenland and Antarctica. Their combined areas represent almost 10% of Earth’s land area. Figure 6.2

8. Types of Glaciers An ice cap is an ice mass that covers less than 50 000 km² of land area (usually covering a highland area.)

9. Types of Glaciers Piedmont glaciers are a type of glaciation characteristic of Alaska - large valley glaciers meet to form an almost stagnant sheet of ice.

10. Malaspina glacier in south-eastern Alaska is considered a classic example of a piedmont glacier. Piedmont glaciers occur where valley glaciers exit a mountain range onto broad lowlands, are no longer laterally confined, and spread to become wide lobes.

11. How do Glaciers Form? As air infiltrates snow, snowflakes become smaller, thicker, and more spherical. The air is forced out of the snow. The snow then recrystallizes into a much denser mass of small grains called firn. Once the thickness of the ice and snow exceeds 165 feet, firn fuses into a solid mass of interlocking ice crystals, which we call glacial ice.