Question

graphing activity: use graphing procedure steps 1 -5 to construct a model of earth polarity.

1. plot the age (millions of years) on the y axis and longitude on the x axis (from data table below).
2. label each dot with the correct polarity, n or s.
3. connect areas with n polarity using a line of one color and areas with s polarity using a different color line.
4. make a key below showing which color represents which polarity.
5. mark where the plate boundary is located on the graph.

part 4. graphing activity
name
sec
date
data table
age (millions of years) | 180 | 160 | 140 | 120 | 100 | 80 | 60 | 40 | 20 | 0 | 20 | 40 | 60 | 80 | 100 | 120 | 140 | 160 | 180
longitude | 30°w | 27.5°w | 25°w | 22.5°w | 20°w | 17.5°w | 15°w | 12.5°w | 10°w | 7.5°w | 5°w | 2.5°w | 0 | 2.5°e | 5°e | 7.5°e | 10°e | 12.5°e | 15°e
magnetic polarity | n | n | s | n | s | s | n | s | n | n | n | s | n | s | s | n | s | n | n

1. draw the magnetic polarity of the seafloor on the strip below. make a key for normal and reverse magnetic polarity. use the data table and the information from the introduction to guide you.

longitude
draw the magnetic polarity here:

Explanation:

Step1: Label graph axes

Label X-axis: Longitude (30°W to 15°E), Y-axis: Age (0 to 180 million years)

Step2: Plot data points

For each pair from the table:

• (30°W, 180 mya, N), (27.5°W, 160 mya, N), (25°W, 140 mya, S), (22.5°W, 120 mya, N), (20°W, 100 mya, S), (17.5°W, 80 mya, S), (15°W, 60 mya, S), (12.5°W, 40 mya, N), (10°W, 20 mya, S), (7.5°W, 0 mya, N), (5°W, 20 mya, N), (2.5°W, 40 mya, N), (0°, 60 mya, S), (2.5°E, 80 mya, N), (5°E, 100 mya, S), (7.5°E, 120 mya, S), (10°E, 140 mya, S), (12.5°E, 160 mya, N), (15°E, 180 mya, N)

Step3: Connect same polarity points

Use one color for all N polarity points, another for S polarity points, connecting sequential matching polarity points.

Step4: Create polarity key

Write: "Key: [Color1] = Normal (N) Polarity, [Color2] = Reverse (S) Polarity" below the graph.

Step5: Mark plate boundary

The plate boundary is at 0° longitude (X-axis midpoint, corresponding to 60 mya on Y-axis), draw a vertical line here.

Step6: Draw seafloor polarity strip

Align longitude (30°W to 15°E) on the strip. Shade segments:

• 30°W-27.5°W: N, 27.5°W-25°W: N, 25°W-22.5°W: S, 22.5°W-20°W: N, 20°W-15°W: S, 15°W-12.5°W: S, 12.5°W-10°W: S, 10°W-7.5°W: N, 7.5°W-5°W: S, 5°W-2.5°W: N, 2.5°W-0°: N, 0°-2.5°E: S, 2.5°E-5°E: N, 5°E-10°E: S, 10°E-12.5°E: S, 12.5°E-15°E: N

Add the same polarity key below this strip.

Answer:

1. The graph is constructed with labeled axes, plotted points, connected polarity groups, a polarity key, and a vertical plate boundary line at 0° longitude.
2. The seafloor polarity strip has shaded segments matching the magnetic polarity for each longitude interval, paired with the polarity key.