Page 568 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

17
Glacial and Periglacial Landscapes
concepts
Key Learning
After reading the chapter, you should be able to:
• Explain the process by which snow becomes glacial ice.
• Differentiate between alpine glaciers and continental ice sheets, and
describe ice caps and ice fields.
• Illustrate the mechanics of glacial movement.
• Describe characteristic erosional and depositional landforms created by glaciation.
• Discuss the distribution of permafrost, and explain several periglacial processes.
• Describe landscapes of the Pleistocene ice-age epoch, and list changes occurring today in the polar regions.
Mount Fitz roy stands at 3375 m in eleva- tion in the glacial landscape of the southern andes in argentina and Chile. Laguna Torre, in the foreground, is one of many glacial lakes in Los glaciares national Park, located near Lago Viedma in the South Patagonia ice Field (see Figure 17.5). Using satellite data from 2000 to 2012, scientists have determined that throughout this ice field, glaciers are thinning, even at the highest elevations, at a rate of about 1.8 m per year. Warming temperatures with climate change are causing melting in the Patagonian ice fields that contribute about 0.07 mm per year to rising sea level; these freshwater losses will affect regional water supplies in the coming years. [Pichugan Dmitry.]