Presentation on theme: "2012 SUMMER INSTITUTE DYNAMIC PLANET Glaciers. 2012 SUMMER INSTITUTE PRESENTED BY Mark A. Van Hecke."— Presentation transcript:
2012 SUMMER INSTITUTE DYNAMIC PLANET Glaciers
2012 SUMMER INSTITUTE PRESENTED BY Mark A. Van Hecke
2012 SUMMER INSTITUTE DISCLAIMER: This presentation was prepared using draft rules. There may be some changes in the final copy of the rules. The rules for this event that are in the current year’s Coaches Manual and Student manuals will be the official event rules.
Presentation Objectives Provide 2012 Summer Institute Participants with an overview of 2013 Dynamic Planet Event Topic Areas and training strategies to use with students. Provide 2012 Summer Institute Participants with an overview of 2013 Dynamic Planet Rules.
2013 Event Description In Dynamic Planet, students will use science process skills to complete tasks related to glaciation and long term climate change
What Students Will Do: Students will be presented with one or more tasks using science process skills including: Analysis and interpretation of erosional and depositional landforms created by glaciers Analysis of geologic maps that include glacial deposits to determine the sequence of events over episodes of glacial advance and retreat Interpretation of oxygen isotope data from a sediment core to identify changes in sea level caused by glacial advances and retreat
Activity One: Make Your Own Glacier In this activity, you will get directions to create and you will observe a melting glacier.
What is a Glacier? A glacier is a thick mass of ice that forms over hundreds or even thousands of years…
What is a Glacier? Snow- and lots of it is the raw material from which glacial ice originates… Over time, the snow compacts into granular or hardened snow
What is a Glacier? This granular snow then recrystallizes to form firn- an intermediate stage between snow and ice
What is a Glacier? Over time, the firn continues to compact and recrystallize into glacial ice Firn is often found underneath the snow that accumulates at the head of the glacier
Make Your Own Glacier Now… let’s make our own glacier First, take a mixture of dirt and rocks of various sizes. Add approximately 1 tablespoon of the mixture per ice cube that you will make. Add water and freeze the mixture overnight
Make Your Own Glacier Take the ice cube (aka the glacier) and turn it upside down onto the surface Next, give the glacier a push forward. You might also push it down slightly into the surface.
Make Your Own Glacier Make observations as the ice cube is melting.. What is happening to the pebbles, dirt and rocks that were in the glacier?
Make Your Own Glacier The piles of dirt could be moraines that are left at the end of a glacial advance
Make Your Own Glacier You might also see large boulders or erratics that appear out of place in comparison to other sediments left by the glacial retreat
Make Your Own Glacier There could also be basins that filled with meltwaters when the glacier retreated. These are kettles or kettle lakes.
2013 Event Topics: The 2013 Dynamic Planet Event will emphasize the following three key topic areas: Glacial formation Glacial and ice sheet types-primarily alpine and continental Glacial erosion, erosional landforms and sediment transport Glacial depositional landforms and sediments Periglacial environmental processes and landforms
2013 Event Topics: The 2013 Dynamic Planet Event will emphasize the following three key topic areas: Glaciers in the hydrologic cycle, impacts on climate, streams, lakes and oceans Pleistocene and pre-Pleistocene glacial history Theories explaining glacial and ice sheet advance Glaciers as indicators of modern global climate change
Forms of Glaciers Alpine glaciers are masses of glacial ice that accumulate in mountainous uplands and plateaus…
Forms of Glaciers Continental glaciers are enormous ice sheets that flow out from one or more centers to completely cover all but the highest areas of underlying terrain…
Erosional Landforms The forward motion of a glacier is known as its ‘flow’…
Erosional Landforms In the process of moving forward, glaciers pick up enormous amounts of debris as they loosen, break off and incorporate pieces and blocks of rock into the ice… This is a process known as ‘plucking…’
Erosional Landforms This embedded material may create long scratches or grooves called ‘glacial striations’ as the glacier moves forward acting like a giant rasp as it moves across the rock…
Erosional Landforms The pulverized rock that results from abrasion is called ‘rock flour…’
Erosional Landforms Cirques Horns
Erosional Landforms Arêtes Kettles
Depositional Landforms: Recall that glacial ice carries enormous amounts of debris within the ice and as it moves forward like a bulldozer scooping sediment in front of it…
Depositional Landforms ‘Drift’ is a general term used to describe sediments of glacial origin…
Depositional Landforms ‘Till’ refers to materials that are deposited directly as glacial ice melts and drops its load of rock fragments…
Depositional Landforms ‘Stratified drift’ refers to sediments that are not directly deposited by a glacier, but rather reflect the sorting action of glacial meltwaters…
Depositional Landforms ‘Erratics are larger rocks and boulders carried by glaciers far from their place of origin…
Depositional Landforms ‘Drumlins’ are streamlined hills composed of glacial till…
Depositional Landforms ‘Eskers’ are depositional ridges made by streams flowing in tunnels beneath the ice
Depositional Landforms ‘Kames’ are steep sided hills composed of sand and gravel…
Depositional Landforms ‘Moraines’ are large deposits of glacial till that form a variety of depositional features…
Depositional Landforms ‘Lateral Moraines’ are ridge like piles of till that accumulate along the sides of valley glaciers…
Depositional Landforms ‘Medial Moraines’ form where adjacent lateral moraines merge into a single long ridge of till…
Depositional Landforms ‘End Moraines’ form where the terminus or end point of an active glacier remains at the same location for a number of years piling up into an increasingly larger ridge or hill…
Depositional Landforms ‘Terminal Moraines’ mark the farthest advance of a glacier.
Activity Two: Identifying Glacial Features on Topographic Maps In this activity, you will identify landforms associated with glaciers on a topographic map. You will need the Hyannis, Massachusetts, Marmot Mountain, Montana, and Palmyra, New York topographic map pages to complete the activity.
Identifying Glacial Features on a Topographic Map: Describe the topography of the map indicated by the red X shown on the screen? What term related to glaciers can be used to describe this topography? Hyannis, Massachusetts X This is a moraine as indicated by the well defined hill/depression zone shown here
Identifying Glacial Features on a Topographic Map: Read the contour lines surrounding the four ‘Bs’ in the northern half of the map. What type of glacial landforms are they likely to be? What category of glacial landforms are the four ‘Bs?’ Hyannis, Massachusetts These depressions are Kettle LakesKettles were formed as large blocks of ice formed depressions and then melted.
Identifying Glacial Features on a Topographic Map: Read the contour lines surrounding areas labeled D in the southern half of the map. What category of glacial landforms are the D Regions of the map? Hyannis, Massachusetts The D regions of the map form areas of outwash plain as indicated by the broad, lower elevation.
Identifying Glacial Features on a Topographic Map: What might account for the swampland in the NW/North Central region of the map? Hyannis, Massachusetts The lower elevated land indicated by the box was depressed by the weight of the glacier at the edge of the moraine creating a broad area of poorly drained land.
Identifying Glacial Features on a Topographic Map: What type of glacial landform likely is indicated by C, O and M? Marmot Mountain, Montana These are cirques-areas- basins where glacial ice accumulates and then begins to flow downward to lower elevations
Identifying Glacial Features on a Topographic Map: What type of glacial landform likely is indicated by N? Marmot Mountain, Montana N indicates a glacial tarn occupying the depression. Tarns are glacial lakes occupying former cirque basins
Identifying Glacial Features on a Topographic Map: What type of glacial landform likely is indicated by B and E? Palmyra, New York B and E are drumlins. Drumlins are formed by glacial ice acting upon ground moraines or till. The lee side (low)of the Drumlin can be used to indicate the direction of ice flow
Identifying Glacial Features on a Topographic Map: What might explain the linear movement of streams F and G in the SW corner of the map? Palmyra, New York The streams lie within lowlands separated by parallel drumlins
Summary: Provide 2012 Summer Institute Participants with an overview of 2013 Dynamic Planet Rules. Provide 2012 Summer Institute Participants with an overview of 2013 Dynamic Planet Event Topic Areas and training strategies to use with students.