Author: Maddie Van Beek

Once again, we are going to be using eggs to learn about science! In the past, we’ve used eggs to learn about osmosis and acid-base reactions.

Today, we are focusing on sedimentation and crystallization. After you learn about these concepts, you are going to make egg geodes! 

Geode: A rock containing a cavity lined with crystals or other minerals. 

First of all, sedimentation is...

The process by which particles (solute) suspended in a fluid (solvent) eventually come to rest due to the forces, such as gravity, acting on them. 

Note: The solute and the solvent (the particles and the liquid they are suspended in) come together to form a solution. As you can see below, over time, the particles (green dots) in the fluid settle to the bottom. 

Crystallization is....

The process in which solid crystals precipitate from a solution or melt (Crystallization can also occur when crystals form from a gas, but this is rare. In our activity today, we are focusing on crystals that form from a solution).  

Can you think of a time that you’ve seen crystallization in the real world? I can! Back in November of last year, we did a snow blog (to see it, click here)! Snow flake formation is just one form of crystallization. Another form of crystallization is with natural crystals or gemstones. This takes a LONG TIME. 

Check out this video to see crystallization in action!

Now that you know a little bit about sedimentation and crystallization, try it out for yourself!

You'll be creating your own geodes inside eggshells. They'll turn out looking similar to the geode below, except you get to make them whatever color you want! 

YOU WILL NEED:

• Eggs
• Push pin
• Bowl
• Small scissors
• White glue
• Small paintbrush
• Egg dye or liquid food dye
• Hot water
• Spoon
• Cup or container 
• Drying area (rack, plate, or newspaper would work fine)
• Alum powder (you should be able to find Alum powder at any grocery store)

HERE’S WHAT TO DO!

1. Have you ever blown out eggs before you decorate them for Easter? That’s the first step to making egg geodes! You will need to carefully poke a hole in both the top and the bottom of the egg with the push pin. When you poke the hole, wiggle the pin around a bit to make the hole bigger. This will make it easier to blow the egg out of the shell.


2. Hold the egg over a bowl and blow on the top of the egg. The egg inside the shell should come out the bottom of the egg into the bowl. You can either throw the egg away, or go ahead and make an omelet! I suggest using your resources to have a great breakfast while you create your geodes :] 

3. This part is tricky. Now that you have an empty egg shell, you will need to use a small scissors to break the shell in half the long way. Don’t worry about it being perfect. As long as you have somewhat of a bowl shape, you are good to go. If your eggshell completely shatters, just blow out another egg and try again!


4. Again, you will have to be extremely careful in this step! Use a piece of paper towel to wipe the inside of the egg clean. Next, use the small paintbrush to coat the inside of the shell with white glue. Before the glue dries, sprinkle the Alum powder generously over the glue so that it coats the whole inside of the eggshell. 


5. WAIT!!! Your eggshell has to dry completely before you can move on. Leave it to dry overnight. 


6. Up and at ‘em? Back to the grind! Measure two cups of water and heat it up. You can either heat it to boiling on the stove or put it in a microwave-safe container and heat the water in the microwave.  Two to three minutes on HIGH should do the trick. 


7. CAREFULLY pour the heated water into the cup or container that you plan on using to create your egg geodes. 


8. Use a generous amount of food coloring to dye the water--30-40 drops is sufficient. 


9. Add 3/4 cup of Alum powder to the colored water and stir it with a spoon until the powder is completely dissolved. 


10. Let the Alum solution cool down for approximately 30 minutes. 


11. Once the solution has cooled down, use a spoon to submerge your Alum-coated eggshell. Make sure the open side is facing up, and the eggshell is resting on the bottom of the container. 


12. Now, the waiting game! Leave your eggshell to sit in the solution for 12-15 hours. Make sure you place the container in a safe place where no one will knock it over! 


13. After 12-15 hours, prepare a drying area. Use a drying rack, newspaper, or paper plate. Use a spoon to remove the eggshell from the solution.


14. Check it out! How has your eggshell transformed? Make sure to take pictures and write down your observations!


FOLLOW-UP QUESTIONS

1. What happened to your eggshell? Describe the change it went through. 
2. How can you relate your eggshell’s transformation to sedimentation and crystallization? 
3. Try to explain the process your eggshell went through. 
4. When does sedimentation and/or crystallization occur in real life? 

Here’s another fun activity about creating Alum crystals that will teach you a little more about crystallization!

References:

• http://en.wikipedia.org/wiki/Crystallization
• http://en.wikipedia.org/wiki/Sedimentation
• http://www.marthastewart.com/343344/crystal-egg-geodes

Image and video credits, in order of appearance:
​
Juppi66, 2009. Ametyst-geode. Uploaded from Wikimedia Commons on 1/8/2017.
https://upload.wikimedia.org/wikipedia/commons/3/3b/Ametyst-geode.jpg File in the Public Domain. 

Van Beek, 2017. Image created by Maddie Van Beek. 

iseen, 2014. Beautiful chemical reactions - Crystallization. Video uploaded from YouTube on 1/8/2017. https://youtu.be/193qXKFMQR8

Heyde, 2007. Geode inside outside. Uploaded from Wikimedia Commons on 1/8/2017.
https://upload.wikimedia.org/wikipedia/commons/thumb/6/60/Geode_inside_outside.jpg/800px-Geode_inside_outside.jpg File used in accordance with the CC Attribution-Share Alike 3.0 Unported. Image was not changed. 

The Sci Guys, 2013. The Sci Guys: Science at Home: Crystallization of Alum - How to Grow Alum Crystals. Uploaded from YouTube on 1/8/2017. https://youtu.be/ojpCexbhxdU

Author: Maddie Van Beek

Summer might be over, but there are still plenty of warm days left to spend outside! Today we are going to make our own sidewalk chalk! Before we start creating, let’s learn about the science of chalk.


What do you think of when you hear the word chalk? Many of you might think of the thin white stick that you use to write on a chalkboard. Or you may have memories of colored sidewalk chalk that you play with outside. Those types of chalk are manmade, but did you know that chalk actually appears in nature? Check out the examples below!


Where does chalk occur naturally?

What is chalk? 
These chalk deposits have built up over many, many years. There are other chalk formations around the world such as the chalk cliffs in Germany and Denmark. Believe it or not, chalk is actually a rock. It’s just soft enough that you can use it to write with. Chalk is made of a substance called calcite, which is actually a form of the mineral limestone. The scientific way of denoting calcite (or calcium carbonate) is CaCO3. While blackboard chalk used to be made of this same substance, it is now usually made of gypsum, or calcium sulfate. That is what you’ll be using to make your sidewalk chalk today. 


Now that you know a little bit about chalk, let’s get started! ​

YOU WILL NEED:

• Toilet paper tubes
• Scissors
• Duct Tape
• Bucket or large mixing bowl
• Wax paper
• Water
• Tempera paint (available at Target, Amazon, and most craft stores)
• Plaster of Paris (gypsum)
• Cookie sheet

Here’s what to do! 

1. Collect about six toilet paper tubes. This is what you will use for your chalk mold. Cover one end of each tube with duct tape. Make sure the tape is secure so none of your chalk mixture will leak out the end. 
2. Measure a 6x6 inch piece of wax paper and cut it out. Roll the wax paper square up and place it inside the unsealed end of one of your cardboard tubes. The wax paper is to keep your chalk mixture from sticking to the inside of the cardboard tube. 
3. Repeat step 2 until you have all six of your paper tubes lined with wax paper. 
4. Measure out 3/4 cup of warm water and pour it into your bucket. 
5. Measure 1 1/2 cups of plaster of Paris and sprinkle it into the warm water. Stir as you sprinkle. The plaster will begin to harden in the next half hour, so you will want to work quickly. 
6. Divide the plaster of Paris mixture into six different bowls. Pick six different colors of tempera paint, and add about 3 tablespoons of paint to each bowl. Stir until the color is evenly distributed. 
7. Place each cardboard tube tape-side down on a cookie sheet, then pour the colored plaster of Paris mixture into each tube (one color per tube). 
8. Move the sheet of tubes to a place where they won’t be disturbed. It will take about three days for the chalk to dry completely. Peel the tubes and wax paper off, and voila! You have your own homemade sidewalk chalk! 

References
Vacker, M. Homemade sidewalk chalk. PBSParents: Crafts for kids. http://www.pbs.org/parents/crafts-for-kids/homemade-sidewalk-chalk/
Chalk. Wikipedia. https://en.wikipedia.org/wiki/Chalk

Images and Video Credits, in order of appearance: 

Taichi, 2005. The needles. Image uploaded from Wikimedia Commons on 8/28/2016. https://en.wikipedia.org/wiki/Chalk#/media/File:The_Needles.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.

Yuvair, 2008. "Nitzana Chalk curves" situated at Western Negev, Israel are chalk deposits formed at the Mesozoic era's Tethys Ocean. Image uploaded from Wikimedia Commons on 8/28/2016. https://en.wikipedia.org/wiki/Chalk#/media/File:Nitzana_chalk_curves_(2),_Western_Negev,_Israel.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.​

Tribble, 2008. Child drawing with sidewalk chalk. Image uploaded from Wikimedia Commons on 8/28/2016. https://en.wikipedia.org/wiki/Chalk#/media/File:Chalk-Sidewalk-Art-0092.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.

Author: Maddie Van Beek

​Have you ever wondered how glass is made? Glass can form naturally over time or it may be man-made. Most of the glass you see every day is man-made, but all glass has the same main ingredient--sand! The sand must be heated to extremely high temperatures in order to melt, and that melted sand changes from opaque to transparent as it cools.


Below is a picture of volcanic glass. This glass was formed from sand that was rapidly heated in a volcano and then cooled.

While naturally occurring glass is formed by sand that has been heated to an extremely high temperature, man-made glass contains other added ingredients such as sodium carbonate and calcium carbonate that make the sand melt at a lower temperature. Without these ingredients, we would have to use a lot more energy to create glass!


Check out this video to watch how glass is made:

We aren’t going to make real glass today, but we are going to use the same concepts to make sugar glass!


How are we going to do this? When you add sugar to water and stir, the sugar dissolves and creates a sugar solution. You may have experienced this if you’ve ever made Kool-Aid--the powder disappears into the water and seems to become one with the liquid. If you mix water and sugar together but then leave the sugar solution alone until the water evaporates, sugar that was once dissolved will remain! Adding a few simple ingredients in this activity (corn syrup and cream of tartar) prevents the solution from crystallizing back into sugar and leaves you with a transparent solid--sugar glass!

YOU WILL NEED:
* Granulated sugar
* Cream of Tartar (you can find this in the spice section of any grocery store)
* Water
* Light corn syrup
* Measuring cups/spoons
* Cookie sheet
* Saucepan
* Stove
* Candy thermometer
* Stirring spoon
* Non-stick cooking spray
* Food coloring
* Fork or toothpick


Here’s what to do!
1. Use measuring cups and spoons to measure out 1 3/4 cup granulated sugar, 1 cup water, 1/2 cup light corn syrup, and 1/8 teaspoon cream of tartar.
2. Combine all ingredients in a saucepan.
3. Spray your cookie sheet with non-stick cooking spray and set it off to the side.
4. Turn the burner on low/medium in order to heat your ingredients slowly. If the solution gets too hot, it will caramelize and turn a yellowish color. Stir constantly as the solution heats up.
5. Once your solution turns clear, you can stop stirring and place the candy thermometer in the saucepan. The solution will begin to boil slowly, but that’s okay. Just make sure not to get splashed!
6. Keep a close eye on the thermometer and remove the saucepan from the burner once the solution reaches the hard crack stage (between 300 and 310 degrees Fahrenheit).
7. Carefully pour the solution into the cookie sheet.
8. Now let your creativity shine! Sprinkle your choice of food coloring onto the cookie sheet of syrup. Next, use a fork or toothpick to swirl the dots of color throughout the syrup. Have fun with it! Just BE CAREFUL to not touch the hot syrup!
9. Leave the cookie sheet in a safe place to cool down. Check back a few hours later and remove your sugary, beautiful creation!


For more science activities that involve crystallization, check out:
* http://www.discoveryexpresskids.com/blog/sedimentation-and-crystallization-how-to-make-egg-geodes
* http://www.discoveryexpresskids.com/blog/sweet-solutions-rock-candy


For more science activities involving baking/cooking, check out:
* http://www.discoveryexpresskids.com/blog/science-of-baking-whats-the-difference-between-baking-soda-and-baking-powder
* http://www.discoveryexpresskids.com/blog/the-science-of-meat-tenderizer


References:
* http://www.instructables.com/id/How-to-make-Sugar-Glass/
* http://science.howstuffworks.com/innovation/28024-some-assembly-required-how-glass-is-made-video.htm
* http://www.explainthatstuff.com/glass.html
* http://www.stevespanglerscience.com/lab/experiments/stained-glass-sugar/

Author: Maddie Van Beek

Once again, we are going to be using eggs to learn about science! In the past, we’ve used eggs to learn about osmosis and acid-base reactions. Today, we are focusing on sedimentation and crystallization. After you learn about these concepts, you are going to make egg geodes! 


Geode: A rock containing a cavity lined with crystals or other minerals. 

First of all, sedimentation is...

The process by which particles (solute) suspended in a fluid (solvent) eventually come to rest due to the forces, such as gravity, acting on them. 

Note:  The solute and the solvent (the particles and the liquid they are suspended in) come together to form a solution.

Crystallization is....

The process in which solid crystals precipitate from a solution or melt (Crystallization can also occur when crystals form from a gas, but this is rare. In our activity today, we are focusing on crystals that form from a solution).  

Can you think of a time that you’ve seen crystallization in the real world? I can! Back in November of last year, we did a snow blog (to see it, click here)! Snow flake formation is just one form of crystallization. Another form of crystallization is with natural crystals or gemstones. This takes a LONG TIME. 

Check out this video to see crystallization in action!

Now that you know a little bit about sedimentation and crystallization, try it out for yourself!


This is what you will be creating!

YOU WILL NEED:

• Eggs
• Push pin
• Bowl
• Small scissors
• White glue
• Small paintbrush
• Egg dye or liquid food dye
• Hot water
• Spoon
• Cup or container 
• Drying area (rack, plate, or newspaper would work fine)
  
• Alum powder--pictured below. You should be able to find Alum powder at any grocery store.

HERE’S WHAT TO DO!

1. Have you ever blown out eggs before you decorate them for Easter? That’s the first step to making egg geodes! You will need to carefully poke a hole in both the top and the bottom of the egg with the push pin. When you poke the hole, wiggle the pin around a bit to make the hole bigger. This will make it easier to blow the egg out of the shell.


2. Hold the egg over a bowl and blow on the top of the egg. The egg inside the shell should come out the bottom of the egg into the bowl. You can either throw the egg away, or go ahead and make an omelet! I suggest using your resources to have a great breakfast while you create your geodes :] 

3. This part is tricky. Now that you have an empty egg shell, you will need to use a small scissors to break the shell in half the long way. Don’t worry about it being perfect. As long as you have somewhat of a bowl shape, you are good to go. If your eggshell completely shatters, just blow out another egg and try again!


4. Again, you will have to be extremely careful in this step! Use a piece of paper towel to wipe the inside of the egg clean. Next, use the small paintbrush to coat the inside of the shell with white glue. Before the glue dries, sprinkle the Alum powder generously over the glue so that it coats the whole inside of the eggshell. 


5. WAIT!!! Your eggshell has to dry completely before you can move on. Leave it to dry overnight. 


6. Up and at ‘em? Back to the grind! Measure two cups of water and heat it up. You can either heat it to boiling on the stove or put it in a microwave-safe container and heat the water in the microwave.  Two to three minutes on HIGH should do the trick. 


7. CAREFULLY pour the heated water into the cup or container that you plan on using to create your egg geodes. 


8. Use a generous amount of food coloring to dye the water--30-40 drops is sufficient. 


9. Add 3/4 cup of Alum powder to the colored water and stir it with a spoon until the powder is completely dissolved. 


10. Let the Alum solution cool down for approximately 30 minutes. 


11. Once the solution has cooled down, use a spoon to submerge your Alum-coated eggshell. Make sure the open side is facing up, and the eggshell is resting on the bottom of the container. 


12. Now, the waiting game! Leave your eggshell to sit in the solution for 12-15 hours. Make sure you place the container in a safe place where no one will knock it over! 


13. After 12-15 hours, prepare a drying area. Use a drying rack, newspaper, or paper plate. Use a spoon to remove the eggshell from the solution.


14. Check it out! How has your eggshell transformed? Make sure to take pictures and write down your observations!


FOLLOW-UP QUESTIONS

1. What happened to your eggshell? Describe the change it went through. 
2. How can you relate your eggshell’s transformation to sedimentation and crystallization? 
3. Try to explain the process your eggshell went through. 
4. When does sedimentation and/or crystallization occur in real life? 

Here’s another fun activity about creating Alum crystals that will teach you a little more about crystallization! 

References:

• http://en.wikipedia.org/wiki/Crystallization
• http://en.wikipedia.org/wiki/Sedimentation
• http://www.marthastewart.com/343344/crystal-egg-geodes
• http://www.stevespanglerscience.com/lab/experiments/incredible-egg-geode

If there’s one thing you find everywhere, its soil!  Few things are quite so universal; all over the world soil takes part in our planting, building, cleaning, and playing.  Without it, none of the crops we use for food, clothing, or fuel could be grown.  Like so many universal things, it is very easy to take our soil for granted; it seems so simple, but soil is really very complex!

What we know as soil is really a mixture of many things:  minerals from the rock—or parent material—from which the soil is formed, organic materials from the organisms that live in the soil—such as plants and bacteria, water, and dissolved gasses—nitrogen, oxygen, and carbon dioxide.   Soil is formed when time and the elements (wind, weather, and living organisms) break down rock and mix in organic materials in different amounts to create the mixture of fine particles, sand, and stones we know generally as soil.

One of the most important characteristics of a particular soil is its texture (that is, how large or small the particles are which make up that soil).  The larger the size of the particles that make up the soil, the more coarse the soil will be.  Also, the smaller the particles that make up the soil, the finer and smoother the texture of the soil will be.  There are essentially three kinds of particles that can make up any soil: 

1.  Sand:  These are very large, coarse mineral particles.  Imagine the sand at the beach, or in a sandbox.  If you rub it between your hands, it is very rough and scratchy.  This is because the grains of sand are very big. Try to squeeze wet sand through your fingers, and it will just crumble.  This is how you can test if soil is made up of a lot of sand.

2.  Clay:  These are the smallest particles you can find in soil.  If you have ever played with modeling clay, you know it is very soft, smooth, and silky.  This is because the particles of the clay are so small—usually you cannot even see the individual particles!  Try to squeeze wet clay through your fingers, and it will form long, smooth ribbons.  This is how you can tell if a soil is made up of a lot of clay.

3.   Silt: These are particles with a medium size, between sand and clay.  Because they have a medium size, silt particles make a soil with a texture that is in between clay and sand.  If you squeeze wet silt through your fingers, it will make ribbons, but these ribbons will fall apart shortly after going through your fingers.

The reason soil texture is so important is because different soil textures hold water differently.  Water is very important for the plants that grow in the soil, so how well the soil holds the water will affect how well that soil is able to grow crops (and if the crops don’t grow well, there will be less food to go around!). 

Soil that is very coarse will let water in, but also lets the water run out very quickly.  This means the water will travel too deep for the plant roots, and will travel too fast for the plant to soak it up.  Very fine soil, like clay, does not let the water in very fast.  In fact the water will often sit on top of the soil, and just evaporate or run off without soaking in!  Plants growing in clay may not get the water they need from this soil either, because the water will not be able to get to the roots. 

Very good soil for growing plants should be a mixture of these soil textures:  enough sand to let water in, but enough clay to hold onto that water, and not let it flow away too quickly.  Soils with equal amounts of sand, silt and clay are called loam, and these are considered the best for growing plants. 

EXPERIMENT WITH DIFFERENT SOIL TYPES!!

Here’s what you’ll need:

1.    2-3 cups each of sandy and clay soil.  You can usually buy these at home improvement stores, or on the internet.  You could also find these soil types in the environment!  Just ask a local county extension agent or Natural Resource Conservation Service soil scientist where to look!

2.    2-3 cups of water

3.    A ½ cup measuring cup

4.    Clear plastic cups

5.    A nail or a pin

6.    A kitchen scale

7.    A sink that can be easily rinsed

HERE’S WHAT TO DO!

1.    Take two of your plastic cups, and poke a few holes in the bottom with your nail or pin.

2.    Put ½ of a cup of the sandy soil in one plastic cup, and ½ of a cup of the clay soil in the other cup.

3.    Place the cups, one at a time, on the scale, and record their weights.

4.    Pour ¼ of a cup of water over each of the cups of soil and place them in the sink.  Allow them to drain for 5 minutes.

5.    Weigh each of the cups again, and record the weights.  How much has each cup gained?  All this weight comes from the water.

6.    Take a look at each cup.  Can you see where the water is?  Where did the water go for the sand soil?  For the clay soil?  Write down what you see!

7.    Now take ¼ of a cup of each soil, and mix it in another plastic cup.  Be sure to poke some holes in the bottom of this cup too!

8.    Weigh the cup with your mixed soil.  Record the weight.

9.    Pour ¼ cup of water over this soil, and let it drain in the sink 5 minutes.

10.  Weigh this cup again, and record the weight.  How much extra weight does this soil have?

11.  Where is the water in this soil?  Is it sitting at the top, or did it move to the bottom?  Is the soil holding onto the water any better than the clay or the sand alone?

12.  Try mixing the soil in different amounts.  Each time you mix the different soils, write down how much of each one you mixed, and then pour ¼ cup of water over it.  Let it drain 5 minutes each time.  Be sure to weigh the soil before and after to see how much water the soil holds. 


What did you find out about how much water the soil will hold?  What was the best combination of sand and clay? 

Try planting seeds in the soil you have mixed.  Choose seeds that do not grow too large.  Remember to water the seeds every day, or whenever the soil feels dry.  Compare the growth of your seeds to the growth of the same kind of seeds in potting soil you can buy at the home improvement store. 

Be sure to WRITE DOWN ALL THE THINGS YOU DO (what types of seeds did you use, how many did you plant, and what type of potting soil did you try), AND ALL YOUR OBSERVATIONS (how many plants grew, how tall did they grow, how much time did it take for the first seedlings to appear)!


References for further reading:

1)       Soil.  Wikipedia.  2014, Mar 12.  Retrieved  3-12-2014.  (http://en.wikipedia.org/wiki/Soil)

2)       Hausenbuiller, R. L.  (1972).  Soil Science: Principles and Practices.  Dubuqe, IA: Wm. C. Brown Company Publishers.  ISBN: 0-697-05851-4.

Almost anywhere you go in the United States, you hear people talk about the glaciers and how they created the landscapes around us.  Geologists and historians explore the landscape, pointing out river basins, hills, and valleys, commenting on the role the glaciers’ played in their formation.   We read about them in books; pictures of great walls and rivers of ice unfurl their majesty across full-color pages.  These giants contain most of the fresh water on Earth (Brown, et al.), are present on every continent except Australia, and their gradual change in size is a great indicator of changes in global climates (Post and LaChapelle). 

But what is a glacier exactly, and how does one form?  How can something so large—and which does not appear to be moving at all—create such dynamic landscapes?

A glacier is body of dense ice formed from long-term accumulation of snow.  This snow builds up faster than it is able to melt or sublimate (evaporate back into the atmosphere without melting), and thus accumulates over many centuries, becoming heavier and heavier.  It becomes so heavy that it moves under its own weight, slowly sliding downhill under the force of gravity, or across a thin layer of water created by water from ice melting at its base.

As the glacier moves along the landscape, it pushes up rock from the terrain under it.  It does this when some of the water melts, flows into the small cracks in the rock below, and then freezes again.  When water freezes it expands (see the answer to “Why does ice float?”), and acts as a lever to pry up pieces of this rock, which then begin to move along with the glacier as it travels.  This is called “plucking”, because the rock was “plucked” from the bedrock.  Some pieces of rock may travel hundreds of miles! 

As glaciers continue to move, carrying their load of plucked rocks and boulders, they also scratch and scrape the landscape underneath, grinding and polishing the bedrock.  The result is called “rock flour”, and it is made up of tiny rock particles smaller in diameter than a human hair.  This is called “abrasion”, and is the other major way in which the glaciers shape and define our landscapes.  This abrasion also causes striations, or gouges in the landscape, along the path of the glacier, allowing geologists to map the progress of the glacier.

Through the plucking and abrasion of the bedrock below, the glaciers produce a variety of different landscape features.  The various hill formations include moraines, drumlins, and roche moutonnée.

Moraines:  Linear mounds of till, an assortment of rocks and boulders surrounded by fine rock flour.  These may appear at the front of the glacier (terminal or end moraines), or at the sides of the glacier (lateral moraines).

Drumlins:  Elongated hills made of glacial till, resembling the shape of an elongated bullet or a thin, rounded wedge.

Roche moutonnée (or “sheep back”):  A rock formation polished smooth, shallow slope on one side, and having a sharp cliff face on the other side.  These are formed when a glacier passes over a rock formation, polishing it as it moves up one side of the formation.  As the glacier tries to move down the other side of the formation, it plucks away rock, creating the sharp face. 

Glaciers also change landscapes by moving through valleys, rounding, widening, deepening, and smoothing their features.  Due to this polishing, a glacial valley will have pointed, triangular cliff faces from the sides of the adjacent mountains, called truncated spurs. 

The points at which glaciers form prior to flowing into a valley are three-sided bowl-shaped cirques, where the snow begins to accumulate to form the valley glacier.  Two or more glacial cirques may form side by side, forming a sharp arête in the middle.  If many cirques encircle a mountain, they form sharp peaks at the top of the mountain, called horns. 

As temperatures rise, and the glaciers begin to melt, they eventually start to recede.  The melting glacier will leave deposits of all the till and debris it has accumulated, leaving hills and mounds of sediments.  Hills and mounds that form as a glacier recedes are called kames, while elongated deposits are called eskers. 

TRY MAKING YOUR OWN GLACIER!*

*Procedures for this activity were provided by Ms. Betsy Watts from Hope, North Dakota.  Thank you to Ms. Watts!

While we don’t have thousands of years to wait for a glacier to form, we can simulate one using a plastic cup, some sand, and a few rocks.  We can simulate the landscape too, using a baking sheet and modeling clay!

Here’s what you’ll need:

1.       2-3 plastic cups

2.       Sand, about half a cup or so

3.       Pebbles of different sizes

4.       3-4 rocks, about 1 inch in diameter

5.       A baking sheet (one you don’t want to use again!)

6.       Enough modeling clay to cover the bottom of the baking sheet, preferably of a pale, muted color

7.       Water from any faucet

Here’s what you need to do:

Put some sand, pebbles, and a few rocks in the bottoms of your cups. Add enough water to just cover the rocks—a little more than one inch in the bottom of the cup.  Place these cups in the freezer overnight.

Meanwhile, press your clay into the bottom of your baking sheet.  This clay will become your glacial landscape.

After sufficient time for the water to freeze, remove your cups from the freezer, and cut the plastic away to release the ice and debris.  These are now your “glaciers”. 

                                                              

Place one of your glaciers, debris side down, onto the clay on one end of the baking sheet.  Apply gentle pressure with your hand, and slowly push the glacier IN A SINGLE DIRECTION along the clay.  You will see striations form in the clay from the debris, and you will push up ribbons of the clay along the front and sides of the glacier. 

When you get to the other end of the baking sheet, allow the glacier to remain there and begin to melt.  Repeat the process with the other glaciers you made.  Because no two glaciers are exactly alike, you will make different formations each time. 

After all your glaciers have melted, take a look at your new landscape and try to identify some of the formations.  Where are the moraines?  Drumlins?  Look at the difference between where your glacier passed, and where it melted.  Where are there more deposits—that is, where did your rocks and pebbles end up?  REMEMBER TO WRITE DOWN ALL YOUR OBSERVATIONS IN A NOTEBOOK!



References for further research:

1)      Brown, Molly Elizabeth; Ouyang, Hua; Habib, Shahid; Shrestha, Basanta; Shrestha, Mandira; Panday, Prajjwal; Tzortziou, Maria; Policelli, Frederick; Artan, Guleid; Giriraj, Amarnath; Bajracharya, Sagar R.; Racoviteanu, Adina. "HIMALA: Climate Impacts on Glaciers, Snow, and Hydrology in the Himalayan Region". Mountain Research and Development. International Mountain Society. Retrieved 16 September 2011

2)      Post, Austin; LaChapelle, Edward R (2000). Glacier ice. Seattle, WA: University of Washington Press. ISBN 0-295-97910-0.

3)      Glacier.  Wikipedia.  2014, Feb 28.  Retrieved 3-2-2014.  (http://en.wikipedia.org/wiki/Glacier)


Licenses:

Wikipedia: Creative Commons Attribution-Share Alike 2.5 Unported license

Wikipedia: Creative Commons Attribution-Share Alike 3.0 Unported license

Take a look at a picture of the inside of a cave (click here to see some wonderful pictures online).  Do you see all those pointy formations on the roofs and floors that look a bit like icicles in winter?  Believe it or not, those are not ice!  The ones hanging down from the roofs are called stalactites, and the ones sticking up from the floors are called stalagmites.  What are stalactites and stalagmites, and how do they form?

Most commonly, stalactites (also called 'dripstones') and stalagmites are found inside limestone caves (a cave is just a large, open space that is underground).  They form when water seeps through the rocks above, picking up minerals along the way, and finally seeping through the cracks in the cave's ceiling where it drips down onto the floor. 

As the mineral-laden water drips from the ceiling to the floor, it leaves some of those minerals behind. 

Slowly, drop by drop, the dripping water deposits enough minerals for this icicle-like shape to form, both on the ceiling of the cave and on the floor, where the drops land. 

This is a very, very slow process--a typical stalactite will grow only 0.0051 inches per year!  That's only about the width of a human hair!  You can just imagine how old those big stalactites and stalagmites in the pictures you saw must be!

TRY MAKING YOUR OWN STALACTITE AND STALAGMITE!

Here's what you need:

1 cup Epsom salts

2 small cups (about 6 oz each)

1 piece of cotton string, 12 inches long

2 metal washers or small bolts

1 piece of cardboard, 6 inches by 10 inches

some water from your kitchen sink

a ruler


Here's what to do:

1. Pour half of the Epsom salts into each cup.
2. Add just enough water to cover the salts in each cup, and stir each for about 30 seconds (don't
   worry, not all the salts will dissolve).
3. Soak the string in water, and squeeze out the excess.
4. Tie one washer to each end of the string, and put each end into one of the cups.
5. Place the cups on the cardboard, far enough apart that the middle of the string hangs about 1 inch
   from the cardboard.
6. Place the cardboard and cups somewhere where they will be left alone, such as on a shelf in your room, or on the counter in your kitchen (ask your parents' permission first!). 
7. Watch the middle of the string, just where it gets closest to the cardboard.  You should see the water start to slowly drip from the string to the cardboard.
8. Observe the cups and string every day at the same time for at least 7 days.  Each time write down what you see.  Very carefully use your ruler to measure how long the stalactite is each day.  BE CAREFUL NOT TO TOUCH IT, OR IT MAY BREAK!
9. Allow the cups and string to sit longer, another 7 days if possible, and continue writing down what you see each day.  Be sure the cups still have some water in them, and add some water if needed.

This is what your experiment should look like: two cups with Epsom salts and water, a piece of string with a washer at each end hanging between the glasses, all on top of a piece of cardboard.

How long was your stalactite after 7 days?  After 14 days?  How much did it grow each day?  You can calculate the average growth per day by taking the length after 14 days, subtracting the length at 7 days, and dividing by 7, like this:

Did your stalactite grow fast or slow, compared to average?


MAKE UP YOUR OWN EXPERIMENT!

How else could you get a stalactite to form?  Remember, a stalactite is just a formation made by the deposition of some solid by dripping water. 

Another type of stalactite is an icicle, which is just a stalactite made from frozen water!  If it's cold outside, try to make an icicle by using a paper cup of water with a tiny hole in the bottom.  Make a few holes in the sides of the cup, just under the rim, and tie the ends of a single piece of string to each hole.  You can make the tiny hole in the bottom of the cup using a needle or a pin (get your parents' help!).  Hang the cup over a branch outside, and fill it with warm water.  Wait and see what happens!