Activity: How Far Does a Lava Flow Go?

Goals:

To measure and understand how volume, viscosity, and slope affect the flow of fluid.

To apply understanding of factors that control lava flows and other liquids.

Procedure:

Part 1.

1. Pick one of the following three experiments to conduct as a group.

a. Viscosity

i. Write a hypothesis based on the following question: What is the relationship between viscosity of a liquid and the surface area it covers?

ii. Place an overhead transparency of a grid on a flat surface.

iii. Pour one at a time the three following solutions on the transparency (space them out): 3 ml soap, 3 ml soap plus 1 cap full of salt (mix well), 2 ml soap and 1 ml of water (mix well).

iv. When the soap stops flowing, measure the area of the flow.

v. Make a data table and record your data.

b. Volume

i. Write a hypothesis based on the following question: What is the relationship between the volume of a liquid and the surface area it covers?

ii. Place an overhead transparency of a grid on a flat surface.

iii. Pour one at a time the three following solutions on the transparency (space them out): 3 ml soap, 6 ml of soap, 9 ml of soap

iv. When the soap stops flowing, measure the area of the flow.

v. Make a data table and record your data.

c. Slope

i. Write a hypothesis based on the following question: What is the relationship between slope of a surface and the surface area a liquid covers?

ii. Place 3 overhead transparency of a grid on your desk. Lay one transparency flat, place a small stick under the middle of the second, and place a pencil under the middle of the third.

iii. Pour 3 ml of soap onto the middle of each transparency.

iv. When the soap stops flowing, measure the area of the flow.

v. Make a data table and record your data.

2. Record your data on the board for the class. On your sheet of paper summarize the results (For example what is the relationship between surface area and slope, volume and viscosity of a liquid?). Was your hypothesis correct?

Part 2. Congratulations! Your group was just hired to be geochemical engineers. Your goal is to figure out one or more ways to either stop, slow down, or divert (change the direction of) lava flows in order to save human settlements (houses, towns, cities, etc.) nearby active volcanoes. In your group, use what you learned from your experiment to come up with a way to achieve this goal. You also use other knowledge that you have about liquid movement.

Talk within your group and write out your ideas in the space below. You can also draw out any of your plans. Do not worry about how much money your solution will cost or how hard it might be to achieve. Be creative!