Module #14 - Glaciers and Glaciation

INSTRUCTIONS FOR TODAY

1. Watch the following Video of the Day: Time lapse proof of extreme ice loss. (19 minutes)

Be sure to make point form notes from this video in your digital video journal. Please make sure this document is SHARED with Mr. Durk. 

3. Read the following information below in Part 1: Background and Terminology. Follow all hyper-links to external websites for activities, demonstrations and videos (if applicable). Copy only KEY information (i.e. the highlighted terms) to your digital notebook (in google docs).

4. Complete Part 4: All About Glaciers Webquest  & Glacier Features Orgnaizer (see below) and complete both. Send your answers using google docs to Mr. Durk using the ugcloud.ca OR submit a paper copy of the worksheet below.

DUE DATE:  Submit all components to Mr. Durk before Module #15 (

Part 1: Background and Terminology 


Please remember to record all definitions and content in your virtual notebook. Definitions can be found by clicking on highlighted words.

There are two main types of glaciations: Continental and Alpine. Continental glaciation occurs when huge ice sheets cover massive areas or even continents. These sheets of ice can be kilometres thick and would take centuries or millennium to form. Only Antarctica and Greenland experience these conditions today. For example, the Antarctica ice sheet covers an area of approximately 13 million square kilometres, larger than the whole of Canada. This massive ice sheet accounts for over 90 % of all glacial ice on the planet.

Alpine, or mountain glaciers, form in higher elevations, and are usually much smaller in scale then continental glaciers. At higher elevations snow gradually turns to ice and this accumulates in alpine glaciers. These alpine glaciers flow down from the mountains into valleys, creating unique landscapes. All glaciers erode, transport and deposit materials, dramatically changing the landscape around them.

Alpine Glaciation

An Alpine Glacier

Erosional features include plucking, where moving ice lifts out blocks of bedrock that have been loosened by the freezing and thawing of the water in cracks in the rock.

Crevasses are also created due to the uneven flow of the glacier as it slides down the mountain. These crevasses can range in size from small cracks to extremely large openings in the glacier which are often covered with a thin layer of snow, making walking on glaciers extremely hazardous.

 



As the ice slides along the bedrock, grooves occurs, creating striations and grooves can be created in the bedrock. These striations can be millimetres wide or large grooves or gouges big enough to create lakes.

Glacial Grooves
Glacial Grooves


Alpine Glaciation erosional features, Courtesy of Luis Maria Benitez

Cirque - horseshoe shaped depressions formed by the erosional action of alpine glaciers

Tarn – when the ice melts out of a cirque, a small lake may form

Arete – when two cirques cut back towards each other, creating a sharp ridge

Horn – when several cirques erode back to form a sharp peak

Hanging Valley – U-shaped valley cut by a smaller tributary glacier that lies at a higher elevation than the deeper U-shaped valley eroded by the main glacier

Moraine – debris deposited by glaciers as they melt or retreat

Lateral Moraine - moraines that form along the sides of alpine glaciers

Terminal Moraine – depostions that acuumulated at the fartherst


Continental Glaciation Featutres
Permission granted by Bruce Railsback, Professor, Department of Geology

 

Eskers - when the glaciers retreat, long, snake-like ridges of sorted sands, gravels and boulders are left behind.

Kames - ponds or depressions left by melting masses of glacial ice.

Part 4: Melting Glaciers and Human Effects (Group Activity) & Glacier Features Organizer

Drop Box Complete the following assignment and submit your work to Mr. Durk via the ugcloud.

Melting Glaciers and Human Effects - Group Case Study

Fill in the following organizer using google docs. Use the following link for pictures and information, copy and paste images from the web into your chart . You may have to look elsewhere to find a description of the feature. Copy this chart below into your virtual notebook, then fill in the descriptions. Cut and past pictures from the internet that correspond with the correct feature.

LEARNING GLACIER FEATURES ORGANIZER

Name of Feature

Description of Feature in your own words

Actual Picture of Feature

Abrasion

 

 

Braided Stream

 

 

Crevasse

 

 

Drumlin

 

 

End Moraine

 

 

Esker

 

 

Groove

 

 

Kame

 

 

Kettle

 

 

Lateral Moraine

 

 

Medial Moraine

 

 

Outwash Plain

 

 

Striation

 

 

Till

 

 

U-shaped valley