Homework #20: Glaciers Name ______ANSWERS ____ Physical Elements (Geography 1) Circle Class: 7:45 am 9:30 am 11:15 am
A. GLACIAL LANDFORM MATCHING Match each of the following terms to the appropriate description below. NOTE: There are two landforms listed for which there are no matching descriptions. a. Arête f. Glacial Trough k Outwash Plain b. Cirque g Hanging Valley l. Proglacial Lake c. Finger Lake h. Horn m. Striation d. Fjord i. Kettle Lake n. Till e. Glacial Erratic j. Moraine
1. Long linear pile of glacial debris left by a retreating glacier ______J 2. Pyramid formation carved by three or more cirques ______H 3. Unsorted rock debris carried by glacial ice ______N 4. Large boulder carried by glacial ice to a location far from its parent rock ______E 5. Submerged glacial valley found along a coast ______D 6. Lake formed in depressions left by ice blocks in outwash plains ______I 7. Gouge or mark left on rock by the abrasion of debris carried by a glacier ______M 8. Valley that’s distinctly deepened, widened and straightened by glacial erosion ______F 9. Lake formed from glacial meltwater trapped by an ice dam or glacial debris ______L 10. Broad circular basin hollowed out by ice at the head of a glacial valley ______B 11. Valley that plunges into a deep trough carved out by a glacier ______G 12. Smooth flat plain formed in front of a glacier by deposition of sediment carried ______K by meltwater
B. GLACIAL LANDFORM PHOTO & MAP EXERCISE Use the photos & topographic maps on the class website to answer the following questions: 1. Topographic Map: Mt. Jackson, Colorado 1:24,000 USGS a. Letter “A” is pointing to Avalanche Peak. What type of glacial landform is this? ______Glacial Horn ______
b. The letter “C” is on a lake in a cirque. On which side of the cirque is its headwall? (Circle one) Northwest Northeast Southeast Southwest
c. How did the shape & spacing of the contour lines help you find the headwall? ______The close spacing of the______contours indentifies the steep slope of ______the headwall ______
2. Topographic Map: Mt. Rainier East, Washington 1:24,000 USGS
a. What do we call the landforms shown by arrows “A” & “B”? ______Moraines______
b. Is that landform created by erosion or deposition? (Circle one) Erosion / Deposition
3. Find the following glacial landforms in the photo below: a cirque, an arête, a glacial trough, and a horn. Label each with a blue pen, using arrows to point to their location in the photo.
Glacial trough Arête
Cirques **There are more than one of most of these Horn landforms in the photo so there are many correct answers.
C. GLACIAL MELTING 1. How much of Earth’s surface was covered during the peak of the last Ice Age? About ______%33
2. How much of Earth’s surface is still covered by ice? About ______%10
3. Why are scientists so concerned about the current melting of the Earth’s glaciers? The melting of continental ice sheets will change Earth’s albedo & its energy balance. The melting of continental ice sheets will also add to sea level rise.
The melting of mtn/ alpine glaciers will reduce local freshwater supplies. The melting of mtn/ alpine glaciers could also cause flooding in some areas. Local areas dependent on winter sports are very concerned about the loss of tourist income too.
4. Why are they concerned about the loss of ice shelves? The loss of major ice shelves will lower Earth’s albedo & contribute to the warming of
the ocean since less of the Sun’s energy will be reflected back to space. It could also affect the ocean’s salinity and impact ocean currents. Although loss of ice shelves is not expected to contribute much to sea level rise, their loss is a sign that Earth’s polar areas are getting hotter than usual—it’s a warning that the ice caps are warming too.