Welcome to ON(line)SC's Virtual Learning!
Good morning naturalists,
Welcome to another week of ONSC online! This week we are going to explore forces of nature, the big powerhouses of the natural world. These are the factors that cause major dramatic change to the earth. Sometimes, these forces take thousands of years to cause major change. Other times, natural forces have the power to completely change large areas in just a few minutes.
These forces of nature are one of the greatest causes of change on earth and today we are going to explore a force of nature that has been shaping and reshaping our world for millions of years: water.
Water is a giver of life, and every living thing on earth needs it to survive. But providing life is not the only special ability water has hidden up its wet sleeves. As water flows over rocks, small soil fragments are worn down (weathered) and carried away by the water bit by bit (eroded). This is one of water's most incredible abilities. Imagine you take a large rough rock and throw it in a stream or river, write down what you think will happen to that rock the longer it stays in the water. Over time, that rock may even be pushed downstream by the water or by other rocks. Other forces can cause weathering and erosion as well. If you created sandstone face paint during week 1, you were weathering those rocks. Any time you track dirt into your house, that soil was eroded from wherever it came from!
Let’s imagine a river flowing over a flat rocky landscape. What might this landscape look like in ten years? In 100 years? In 1,000 years?
If you really want to see water’s power of erosion just look at the Ozarks. The Ozarks were literally created from water eroding away layers of rock to create the hills and valleys we see today.
Watch this video to learn more about erosion, weathering, and the shaping of Ozark streams
Was water able to erode down rock to create the Ozarks in ten years? Of course not! It took millions of years of erosion for the Ozarks to become what they are today. In places like the Ozarks, water can do more than just create mountains and valleys. If you live outside of the Ozarks, take some time to learn about the hydrology, or relationship between land and water, around you!
In places throughout the Ozarks, you can find a special rock called limestone, which is made up mostly of a mineral called calcium carbonate. This mineral breaks down in the presence of acids, including rainwater. When this limestone erodes away, it creates caves and sinkholes. This Karst topography is a common feature in many parts of the country.
The caves formed by this action are fascinating places that can have all kinds of amazing animals living in them. Animals that live in caves can be called troglofauna, and include many species of insects, fish, salamanders, and more! In fact, some species of animals are endemic to individual caves, meaning that they cannot be found anywhere else on the entire planet! An example of this in Arkansas is the Hell Creek Cave Crayfish, which can only be found in two small cave systems and one spring. You can learn more about them here (https://www.fws.gov/arkansas-es/Species/inverts/HCC.html). Although some of the writing is written more for adults than students, it is still an interesting look at a secretive animal. What adaptations do you think troglofauna have that allow them to survive in the complete and total darkness of a cave?
This bat is perfectly comfortable living in a cave. Would you want to live down there?
The forces that create caves usually take a very long time for water to erode away enough rocks and soil for any change to be noticeable to our eyes. However, it can be full of surprises. Sometimes water can cause major change to a habitat very quickly. When an area receives too much water or a large amount of water in a short time it can cause a flood.
Floods can occur in cities or out in the country, and are not always found near large bodies of water. Thousands of floods occur around the world every year and they have major effects on nature and humans alike. Have you witnessed a flood before? If so, write down what it was like or what you remember about it. What was the weather like leading up to it? Did the area flood slowly, or was it a flash flood where large amounts of flooding happened very quickly? What did the area look like after the flood?
Floods change both the living (biotic) and nonliving (abiotic) parts of an ecosystem.
When you think of the effects of flooding what comes to mind? A flood can have both positive and negative effects on nature. Floods can wash away large amounts of natural habitat and cause huge amounts of erosion in a short time. However, floods also leave behind soil rich in nutrients that creates great places for new trees and plants to grow.
So water is a major force of nature when there is too much of it. But what happens when there is not enough water? When an area does not receive enough water for an extended time it is called a drought. Every living thing needs water to survive so when there is not enough water, plants start to dry up and animals don’t have enough to drink.
What happens to the geosphere when it dries out?
Isn’t it amazing how water can be a major force of nature whether there is just enough water, not enough, or too much of it? With enough time even a small amount of water can be a major force of nature. For many of us, we like it best when there is enough water to go down to the creek and search for crawfish and other creatures in the water.
Now that we’re all excited about the force of water, let’s see it in action! If you have access to a yard, go outside and gather some natural items like rocks, sticks and leaves. Take these items and use them to make a piece of nature art. Leave your finished artwork outside somewhere where you can easily see it or will easily remember where it is. Every day go to check on your piece of art and see how water and other forces of nature are affecting it. For inspiration, our teacher naturalists recommend the work of Andy Goldsworthy, whose sculptures are made of natural materials and are designed to be worn down by nature!
If you do not have access to a yard with rocks, sticks, leaves, or similar materials, you can still mimic the forces of nature in your art. This activity requires paint (thinner works better. We love watercolors!), a straw, and something to place on your work surface to protect it. We like to use newspaper or an old towel.
Gather your materials and set up your work space. Take the paints you want to use and put a few drops on one of the pieces of paper. Blow through the straw to spread the paint across the paper making a beautiful piece of art. What force of nature are we mimicking here? When you are done with your art, try letting one painting dry in a dark place, and store another in a place with plenty of sunlight. Check on them the next day and see what being stored in such different places has done to them. Did the forces of nature change how your work dried?
Well naturalists, that wraps up our discoveries for today on water as a force of nature. Before you swim away, be sure to join us tomorrow as we discover another fantastic force of nature. Also, remember to check out our Facebook page or Socialmedia@onsc.us and send in any nature questions you have. We will be featuring them on our Find-Out Friday at 11:00AM CST.
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