Magnetic Stripes Lab 1.30.12
In the 1950's, magnetometers were used to detect the location of submarines. While watching for enemy subs, odd magnetic readings were discovered in the oceanic crust. Oceanic crust is primarily made of basalt, which contains magnetite. Sometimes the magnetite was aligned with the North Pole or had normal polarity, but sometimes the magnetite had a reverse polarity that was aligned with the South Pole. Further study found the stripes of oceanic crust emerging from the seafloor ridges formed a pattern of alternating stripes of normal and reverse polarity. This led scientists to believe a reversal of the location of the poles had occurred multiple times during the history of Earth.
Draw a diagram of your Magnetic Stripes activity. Use a red map pencil to show the crust with alternating normal and reverse polarity.
Draw a diagram of your Magnetic Stripes activity. Use a red map pencil to show the crust with alternating normal and reverse polarity.
1. Describe what pattern occurred in your model.
The red and plain sticks had matching numbers on both sides up to eleven.
2. If samples of "red" basalt crust material in your model, from the same number on each side of the ridge, what would lab tests reveal about the polarity of the material?
3. If samples could be taken from "white" basalt crust material in your model, from the same number on each side on the ridge, what would lab tests reveal about the polarity of the material?
They would show that the "white" basalts have normal polarity.
4. How does this pattern of alternating polarity support the theory of plate tectonics?
That the continents with their polarity might be pulled and attracted to the poles.
The red and plain sticks had matching numbers on both sides up to eleven.
2. If samples of "red" basalt crust material in your model, from the same number on each side of the ridge, what would lab tests reveal about the polarity of the material?
3. If samples could be taken from "white" basalt crust material in your model, from the same number on each side on the ridge, what would lab tests reveal about the polarity of the material?
They would show that the "white" basalts have normal polarity.
4. How does this pattern of alternating polarity support the theory of plate tectonics?
That the continents with their polarity might be pulled and attracted to the poles.