Wednesday, February 1, 2012

February Nature Net News - Glaciers

"The glacier was God's great plough set at work ages ago to
grind, furrow, and knead over, as it were, the surface of the earth"
Louis Agassiz
Dear Reader,

The Wisconsinan Glaciation happened around 12,000 years ago and was the last age of the mighty glaciers. A huge ice sheet covered most of Canada, the upper Midwest and New England - and it was named after Wisconsin!

These mighty masses of ice and gravel traveled across the land, straightening and shaving the land. When they melted, they left behind their debris, creating some unique and beautiful landforms. The evidence still remains today in many a state trail or wooded valley.

Wisconsin happens to be home to some of the world's finest examples of continental glaciation. Check out these ancient, natural wonders and learn how they shaped our world today in the latest issue of Nature Net News.


Kathe, Sarah & Brenna
The Folks at Nature Net

Did You Know..... 
 A glacier is a river of ice that moves under the pressure of its own weight. Even though they move verrry slowly, glaciers are constantly changing and flowing.

Approximately 10% of the Earth today is covered by glaciers; during the last Ice Age, they covered one-third of the Earth’s surface.

Today's glaciers store about 75% of the world's freshwater. 

What To Do This Month:
 Hike parts of the Ice Age Trail to see remains and landforms left by the Wisconsinan Glacier across the state.

Visit the UW-Geology Museum to learn about glaciers and imagine yourself in the Ice Age. Family-friendly Storytime is on first and third Thursdays at 10:30am.

Watch PBS Kids' DragonflyTV episode on glaciers, read Perry Bear's Glacier Adventure from Alaska, and learn more from the National Snow & Ice Data Center.

Check out Nature Net's Events Calendar for other fun February ideas!

Tricks of the Trail for Parents:
Giant Glaciers
Because they are so huge and move so slowly, it's hard to imagine giant glaciers sweeping the land. Here are some tips to keep it in perspective for you and your kids:

A single crystal of glacier ice can grow to be as large as a baseball. Let's put this in perspective: a usual ice crystal is about the size of a single snowflake.

The thinnest a glacier usually gets is 50 feet (that's about the height of a 5 story building.) At its thickest point, the North American glacier was two miles tall!

Glacial periods and ice ages last for tens or hundreds of thousands of years. the Wisconsin Glacial Episode extended from approximately 110,000 to 10,000 years ago.

Instant Outdoor Expert:
Glacier Terminology
Glaciers have covered parts of North America several times throughout Earth's history, and have reshaped the landscape each time. The Wisconsinan Glacier may have melted 12,000 years ago, but there are still plenty of signs that it was here. Keep your eyes out for these glacial land features all around us!

Drumlin: Oval teardrop-shaped hill formed under the glacial ice near the advancing front of a glacier.

Erratic: Boulder or large rock carried by glaciers and deposited on the surface of the land after the ice melted.

Esker: Long, narrow ridge of coarse gravel deposited by a stream flowing in an ice-walled valley or tunnel in a melting glacier.

Kame: Created as the glacier melted in place, kames (pronounced like "came") were where debris melted through the ice, like a reverse funnel. They appear as conical hills.

Kettle: A depression formed by the melting of a large block of glacial ice that was partially or completely buried. Some kettles hold water to form kettle lakes or marshes or bogs.

Moraine: Jumbled hills of unsorted, unstratified glacial debris found at the sides or front of a glacier.
  (information from Ice Age in Wisconsin)

Featured Nature Net Site
Madison Conservation Parks
Visit Glacier Crossing Park for some real ice age evidence. This unique Madison park is on the Ice Age Trail, a thousand-mile National Scenic Trails footpath highlighting Wisconsin's world-renowned Ice Age heritage and scenic beauty. Hike the hills and discover the drumlins left during the Wisconsinan Age!

The City of Madison Parks Division Conservation Section has 14 different and unique conservation parks. A conservation park differs from other city parks in how it is managed and why the land was acquired. The goal of the conservation park is to return the land to its original state, restore native plant and animal communities, and provide education areas and opportunities for everyone.

Learn About Other Nature Net Sites

Nature Net Craft
Make Your Own Glacier!

What you need: large old bowl or container, ice cubes, dirt with pebbles in it, plate or tray, timer.

1. Put several ice cubes in the bowl so they cover the bottom.

2. Tightly pack dirt and pebbles on top until the bowl is half full.

3. Drizzle water carefully on top.

4. Leave outside overnight to freeze into a solid block.

5. Remove glacier from the bowl and set on a plate or tray. Set the timer for 10 minutes. Every 10 or so minutes, come back to see how your glacier is melting. Discuss what changes are occurring. Can you spot any "landforms" being created by your glacier?
(Nature Craft from Type-A Parent)

Nature Craft Archives

Suggested Reading:
"Glacier Babies!" by Bob Rozinski and Wendy Shattil (baby)
"Glacier National Park: An ABC Adventure" by KC Glassetter and Jeremie Hollman (preschool)
"Icebergs and Glaciers" by Seymour Simon (4-8)
"Icebergs, Ice Caps, and Glaciers" by Allan Fowler (4-8)
"The Glaciers are Melting!" by Donna Love (4-8)
"Glaciers" by Sally M. Walker (4-8)
"Exploring Glaciers" by Melody S. Mis (4-8)
"Glaciers: Nature's Icy Caps" by David L. Harrison (4-8)
"Why Do Glaciers Grind?: All About Extreme Environments" by Helen Bethune (9-12)
"Glaciers" by Larry Dane Brimner (9-12)
"Bodies from the Ice: Melting Glaciers and the Recovery of the Past" by James M. Deem (9-12)

Find Family Events on the Nature Net Calendar of Events

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