Be able to explain how glaciers are able to erode the

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Be able to explain how glaciers are able to erode the landscape -Moving ice has a lot of power, it sculpts and grinds away rock beneath -transports sediment away and deposits it elsewhere Glacial erosion produces steep-sided valleys and pointed mountains - Be able to explain how the following landscape features form due to glacial erosion and identify them from photos/diagrams: o polished surfaces and striations o roche moutonees o U-shaped valleys and fjords o hanging valleys o cirques and tarns o o arêtes and horns
- Understand that glaciers pick up and transport sediment Glaciers move pick up rock as it moves incorporating them into their internal Flow- Plucking-which deepens valleys. Eventually they are dumped at the terminus -they also transport rick that falls onto the glacier - Be able to explain how the following landscape features form due to glacial deposition and identify them from photos/diagrams: o moraines and lakes Moraines: rock and sediment build up at the front, edges, and center of the glaciers -mark the furthest extent of glaciers Lakes often form by meltwater behind moraines as glaciers retreat o erratic boulders larger boulders deposited by ice o kettle lakes ice blocks calve off glaciers and then are buried into sediment, melt , and crated kettle lakes o eskers Long ridges of sand and gravel -formed by meltwater channels o drop stones large rock fragments that are incorporated into ice, when icebergs travel offshore and melt, rocks fall into the ocean. From Lecture 21 and Lecture 22 – Ice cores and the glacial world - Importance of ice core records to our understanding of how and why climate can change - Be able to fully explain how we reconstruct the following from ice cores: o Composition of the atmosphere (bubbles) air bubbles that are trapped into the ice air bubbles are younger than the ice surrounding it o Air temperature (oxygen isotopes) O18 is heavier than O16 -During a colder period, the ocean will have a higher 18O/16O o Particles in the atmosphere Ash and sulfur large volcanic eruptions, dust and sea salt can indicate how dry/windy climate it, soot from forest fires, and pollution from Humans - Be able to explain what causes the Greenland ice core record to be so different from the Antarctica ice core - Be able to explain what the Antarctic ice core record shows: o Milankovitch control on formation and melting of ice sheets Milankovitch cycles explain timing if ice ages but not magnitude of changes o why northern hemisphere seems to control glacial/interglacial cycles - Glacial world – be aware that there were: o Large ice sheets and glaciers in North America, Europe and Asia, South America
o Greater sea ice extent and permafrost extent o Lower sea level by 120m o Mostly dryer with less rainforest and more desert - Be able to explain the effect of sea-level change during the last glacial on dispersal of Homo sapiens Lecture 23 – Melting Glaciers: Glacial Outburst Floods - Mountain glaciers worldwide are melting and will continue to melt at increasing rates -

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