21: Glaciation
- Page ID
- 29201
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- Define, draw, and describe the major features of glaciers
- Explain the differences between continental and alpine glaciation
- Summarize how snow and ice accumulate above a glacier’s equilibrium line and are converted to ice
- Explain how basal sliding and internal flow facilitates the movement of ice from the upper part to the lower part of an alpine glacier
- Describe and identify the various landforms related to alpine glacial erosion, including U-shaped valleys, arêtes, cols, horns, hanging valleys, truncated spurs, drumlins, roche moutonnées, glacial grooves, and striae
- Identify various types of glacial lakes, including tarns, finger lakes, moraine lakes, and kettle lakes
- Describe the nature and origin of lodgment till and ablation till
- Describe the nature and origin of glaciofluvial, glaciolacustrine, and glaciomarine sediments
- Describe the timing and extent of Earth’s past glaciations, going as far back as the early Proterozoic
- Describe the important geological events that led up to the Pleistocene glaciations
- Explain how the Milankovitch orbital variations along with positive climate feedback mechanisms may have controlled the timing of the Pleistocene glaciations
- 21.1: Types of Glaciers
- This page covers two types of glaciers: continental and alpine, highlighting their formation and importance, particularly in freshwater storage and potential sea-level rise. It explains the dynamics of glacier movement, including stress, deformation, and mechanisms like basal sliding, which varies by temperature and ice thickness. It further details how these factors influence overall glacier advancement or retreat.
- 21.2: Glacial Erosion
- This page discusses the role of glaciers in erosion, emphasizing that they primarily erode through abrasion from embedded rocks. It highlights the effects of continental glaciers, which create flat bedrock and landforms like drumlins and moraines, and alpine glaciers, which carve U-shaped valleys and fjords.
- 21.3: Glacial Deposits
- This page discusses glacial sediments in Canada, highlighting their importance as construction aggregates and groundwater sources. It categorizes these sediments by their transport methods: supraglacial, englacial, and subglacial, and describes formations like moraines, tills, eskers, and drumlins shaped by glaciers.
- 21.4: Glaciations over Earth’s History
- This page explores Earth's glacial history, highlighting the current milder glacial period and significant glaciation events such as the Huronian and Cryogenian periods, influenced by atmospheric carbon dioxide changes. It discusses Cenozoic glaciations, emphasizing the impact of tectonic plate movements and ocean currents on climate cooling.
- 21.5: Chapter 21 Summary and Key Term Check
- This page provides an overview of glaciers, distinguishing between continental and alpine types. It covers their movement, erosion processes, and the resultant geological features such as U-shaped valleys and moraines. The chapter also discusses material deposition, including till and moraines, and highlights key historical glaciations like "Snowball Earth" and the Pleistocene Glaciation, linking them to Earth's orbital changes.