Breaking Up is Hard to Do
Living
Agents of Change
Living things can also weather and erode rock. Plants have roots as you know. The roots can force themselves between rocks. As the plant grows, the roots grow, forcing rocks apart. This is called root pry.
Do it!
- Take a walk around your neighborhood.
- Look for signs of plant weathering. Describe what you observe.
- If you have a camera. Take pictures of the evidence that plants have caused sidewalks, roads or even playgrounds to weather.
Do it again!
- At home and with parent permission, you will use a frosted pastry such as a Zingers® or Ho Ho’s® for this activity.
- You will also need toothpicks.
- With a friend, begin inserting toothpicks into the pastry, applying a bit of upward pressure.
- What changes in the pastry do you observe, what happens to the frosting?
Analysis:
- How is the pastry like a structure affected by plant weathering?
- How are the toothpicks like plant roots?
Animals
can physically break rock down and move particles away. Marmots scratch
and move material while digging dens. Ants haul pebbles. We humans skip
rocks across the lake.
When
winter comes water will penetrate those cracks just like it did the road
surface. The water will freeze, widening the cracks and breaking the rock.
Spring's thaw will carry particles away. Gusty winds hit the rock's surface,
picking up tiny particles. These particles blow about, not unlike a sandblaster,
wearing down even more of the surface.
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| Get the plug-ins: Want to share photos of you or your friends doing this activity? Send in an e-mail with the following information: the title of the activity, the URL (Internet address), and your name. Remember that no pictures can be used which show any student faces or has a student name. Updated July 5, 2005 by: Glen
Westbroek |
