Steps of how a glacierice sheet formed definition of

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Steps of how a glacier/ice sheet formed-Definition of a glacier and how they are classified based on shape and base temperature-Alpine glaciers: Characteristics of and how to identifyoCirque glaciersoValley glaciersoTidewater glaciersoIce caps-Continental glaciers: Characteristics of and how to identifyoIce sheetsoIce shelves-Base temperature: Characteristics ofoTemperate glaciersoPolar glaciers
oWhat are theyFrom Lecture 15 – Glacier Mass Balance-What is accumulation and what factors affect accumulation-What is ablation – types of ablation (sublimation, surface melting, basal melting, calving), where they occur and what factors affect each-What is the equilibrium line and can you identify it on a diagram or photo-How the amount of accumulation vs ablation will affect the mass of the glacier and so whether it will advance or retreat-How to interpret a graph showing total accumulation, total ablation, resulting mass of ice over a year, final net balance of ice for the year-How to identify or draw a graph of mass balance for the whole glacier for several years if given accumulation vs ablation-How to identify or draw a graph of mass balance for different areas of a glacier over one year-Be able to identify areas of ablation, accumulation and equilibrium line based on a graph of mass balance (as we did in the South Cascade Glacier example)From Lecture 16 - Measuring glacier mass balance and Ice Dynamics-How easy is it to measure mass balance for a glacier-Measuring mass balance manually:oAccumulation – using stakes, snow pits at end of winteroAblation – ablation stakes from end of winter to end of summer-Measuring mass balance remotely:oUsing change of elevation using lasers, change in mass using gravity measurementsoChallenges of using satellites-What changes have we seen in glacier mass balance through time and in different regions of the world-How we can use the terminus position of glaciers instead to estimate glacier mass changes (advance vs retreat)-Most glaciers today are retreating but some glaciers are advancing-Different responses to climate change due to increased temperatures, more precipitation, feedback mechanisms – different glaciers will be affected by all of these to varying extents-Very rough idea of how glacier mass is likely to change over the next 100 years based on different temperature rises-A glacier has a mass budget but also MOVES = glacier dynamics – transport of ice from source area to sink area-Why ice moves -What is the driving stress and what factors affect it-Why glacier ice is described as a visco-plastic material-Two types of glacier motion:oBasal slidingDefinition
What type of glacier it occurs in and whyOccurs when driving stress is greater than basal drag (friction)Factors that affect basal drag (friction)oInternal DeformationDefinitionWhat type of glacier it mainly occurs in and why

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