EAS100 Lecture Notes - Lecture 21: Fjord, Cryosphere, Permafrost

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS100
• Professor: Alessi,Daniel

Document Summary

Eas 100 lecture 19 glaciers and the cryosphere. A glacial surge is a period during which the glacier advances much more rapidly than normal at a rate of several kilometers a year: likely related to the buildup of meltwater refreezing at the base. Recently (over the past few decades) the majority of glaciers are showing a consistent trend of rapid retreat. It"s been predicted that the bc and alberta glaciers will shrink to 70% of their current size by the year 2100: retreat may be even more rapid in fjord glaciers retreating from a sea-floor shoal. Icebergs are created when there is frontal calving from a fjord glacier: remember titanic! Icebergs dangerous because 90% of mass is below sea level and likely not visible when in a boat or plane above ground. Glacial erosive mechanisms: abrasion, plucking, freeze/thaw cycle at base of glacier. As a glacier retreats/ablate, the leave behind large amounts of loose sediment in their path.