Shake, Rattle, and Sink

Standard III

Students will understand that gravity, density, and convection move Earth's plates and this movement causes the plates to impact other Earth Systems.

Objective 02

Describe the processes within Earth that result in plate motion and relate it to changes in other Earth Systems.

Indicator b

Model the movement of materials within Earth.

Intended Learning Outcomes:

  1. Use Science Process and Thinking Skills
    1. Construct models, simulations and metaphors to describe and explain natural phenomena.
  2. Manifest Scientific Attitudes and Interests
    1. Raise questions about objects, events and processes that can be answered through scientific investigation.
  3. Demonstrate Awareness of Social and Historical Aspects of Science
    1. Cite examples of how science affects human life.

Description of Activity:

Overview
Students will explore the idea and properties of Liquefaction through the use of Ooblick

Duration of Activity - 30 minutes

Materials:

  • Ooblick
    • Combine two parts corn starch to one part water)
  • Plastic shoebox or plastic box
  • Newspapers on floor and tables
  • Blocks of wood of different shapes and weight.
  • Other objects of differing shapes, sizes, and weights (that would fit into the shoe box).
  • Paper
  • Pencil
  • A local map of Liquefaction probability during earthquake activity, if available.

Background Information:

  • This exeriment can be used to demonstrate the structure of the earth, and the reason damage to buildings during earthquakes varies based on the type of foundations they are constructed on..
  • Liquefaction is the changing of properties of a solid upon the addition of water or seismic waves.
  • Some solid soils will turn to quicksand-like material if just the right amount of water is added to them. Sand is notorious for this. In the case of Liquefaction, the water comes from the ground water underneath. If the water table is relatively shallow and close to the surface it happens quickly.
  • During an earthquake, siesmic waves can cause sand and other soils to demonstrate the properties of water even if no water is present.

Teaching and Learning Strategies:

Ensure Inquiry
Students will use various weights and movements to discover the properties of Liquefaction which happens when ground water seeps into, and saturates the soil. It is an exploratory activity so you do not want to give any information about what they will find out.

Prerequisite Instruction
Only tell the students that they are going to see what
happens when ground water saturates the soil above it. This can happen in old stream beds or during the shaking of an earthquake.

Invitation to Learn:

Problem: To construct a Liquefaction model and determine the problems associated with Liquefaction during seismic activity.

Instructions:

  1. Provide each group a box containing dry corn starch (about two to three cups), and a glass of water (about 1 1/2 cups).
    • They should not mix the ingredients until told to do so.
  2. Ask students to write down as many observable characteristics about the dry corn starch "soil" as they can discover.
  3. Instruct students to add the water to the corn starch beginning at one corner of the container.
    • The water is NOT to be mixed into the corn starch at this time.
    • Observe and record any new characteristics of the mixture.
  4. Gently shake the box from side to side and record new characteristics.
  5. Carefully mix the corn starch and water thoroughly using your hands. Observe and record new characteristics.
  6. Explore what happens when objects of different shapes and weights are placed on top of the mixture.
  7. Identify locations and occurrences where a similar thing might happen in nature.
  8. Record recommendations for overcoming the problems associated with Liquefaction.

Safe Operating Procedures

  • Keep your hands over the boxes and newspaper so you do not spill on the floor.
  • You may want to wear aprons to keep mixture off your clothes.
  • Once the Ooblick dries, it can easily be cleaned up with a putty scraper and swept away. Do not use wet paper towels.

Summary of Learning:

Assessment
Ask students to share their observations on the board. Have the class discuss locations, problems, and solutions for Liquefaction. Relate this activity to local or regional areas of possible future earthquake activity.

Suggested questions

  1. What were the differences between the dry "soil" and the "liquefied soil"?
  2. Which type of soil could hold more weight?
  3. When did the "soil" become more mixed, when it was allowed to soak, or when you shook the box?
  4. Do you think this could happen quickly or slowly during an earthquake?why?
  5. Why would it be dangerous to ride cars or motorcycles along old riverbeds? What is this stuff called? (quicksand)
  6. If you are stuck in quicksand while out riding what is the best way to escape? Does this apply during Liquefaction in an earthquake?
  7. How could people build or deal with this problem if they know they are in an area where Liquefaction could happen?

Multiple choice questions

  1. What areas of the Wasatch Front would experience Liquefaction? Areas on
    1. Bedrock
    2. Sand
    3. Clay
    4. Gravel
  2. What type of buildings would do better on potential Liquefaction soil?
    1. One story, spread out buildings
    2. Narrow, linear buildings
    3. Tall, skyscraper-type buildings
    4. Buildings made with heavy materials