Show: Exploring >40 m Tall Active Black Smoker
Explain: Environments associated with underwater volcanoes are extreme and fascinating "other worlds". Hydrothermal vents, called "black smokers", are dynamic features found on underwater volcanoes. They are much like hot springs that you might see on land, but they reach much higher temperatures, form metal deposits the size of the Roman colosseum, and host some of the most novel organisms on Earth that grow at temperatures of 252°F.
The chimneys can be very fast-growing (>30 feet in a year) and some are rich in precious metals that include copper and gold. They are commonly contain zinc- and iron sulfide-bearing minerals such as pyrite (fools gold), and are strengthened by silica that ills the pore spaces. As the super-heated fluids spewing out of the chimneys, like that from a fire hose, mix with near freezing seawater at depth, very small metal-sulfide particles form in the plume, which gives them the black color and hence their name.
The water flowing out of black smokers, which can reach >700°F, is hot enough to destroy your skin. Scientists working at the University of Washington, which are funded by the National Science Foundation, explore for black smokers where the hot and cool water mix.
Today we will model thermal energy transferring from a hydrothermal vent to the cooler ocean water surrounding it.
Explain: Each student group will need a small Erlenmeyer flask, tongs, red food dye, electric kettle (or way to heat water), clear bowl or tub, cold water (approximately 15° Celsius), hot water (approximately 80° Celsius), pencil, red colored pencil, safety glasses, and the optional student Model a Hydrothermal Vent Student Lab Sheet.
**Extreme caution must be taken when handling hot water in a classroom
- Heat water in kettle to approximately 80°.
- Fill the clear bowl or tub with cold water (teacher prep ahead of time might include making ice water and removing the ice prior to the lab).
- Fill the Erlenmeyer flask with heated water; add 5 drops of red food dye to the heated water in the flask.
- Using tongs, grasp the neck of the flask carefully.
- Gently lower the flask through the cold water and place the flask on the bottom of the cold water container.
- Record your observations on the lab sheet.
Check for Understanding (formative assessment)
Ask: What did you observe? How does temperature affect density?
Use students’ recorded observations from the "Model a Hydrothermal Vent Student Lab Sheet" to check for understanding.