Question

1. graphing activity. use graphing procedure steps 1 - 5 to construct a model of earth polarity.
2. plot the age (millions of years) on the y axis and longitude on the x axis (from data table below).
3. label each dot with the correct polarity, n or s.
4. connect areas with n polarity using a line of one color and areas with s polarity using a different color line.
5. make a key below showing which color represents which polarity.
6. 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

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

Step2: Plot data points

For each pair:
$(30^\circ W, 180, N), (27.5^\circ W, 160, N), (25^\circ W, 140, S), (22.5^\circ W, 120, N), (20^\circ W, 100, S), (17.5^\circ W, 80, S), (15^\circ W, 60, S), (12.5^\circ W, 40, N), (10^\circ W, 20, S), (7.5^\circ W, 0, N), (5^\circ W, 20, N), (2.5^\circ W, 40, N), (0^\circ, 60, S), (2.5^\circ E, 80, N), (5^\circ E, 100, S), (7.5^\circ E, 120, S), (10^\circ E, 140, S), (12.5^\circ E, 160, N), (15^\circ E, 180, N)$

Step3: Connect same polarity points

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

Step4: Add key and plate boundary

Create a key for N/S colors; mark plate boundary at $0^\circ$ longitude (midpoint of the graph).

Step5: Draw polarity strip

On the lower strip, shade segments matching the table's polarity: start with N (30°W to 25°W), S (25°W to 20°W), N (22.5°W to 20°W), S (20°W to 15°W), N (12.5°W to 12.5°W), S (10°W to 10°W), N (7.5°W to 2.5°W), S (0° to 0°), N (2.5°E to 2.5°E), S (5°E to 10°E), N (12.5°E to 15°E), with the plate boundary at the central peak.

Answer:

1. A completed graph with labeled axes, plotted points connected by color-coded lines (for N/S polarity), a polarity key, and the plate boundary marked at $0^\circ$ longitude.
2. A completed lower strip with shaded segments corresponding to the magnetic polarity data, a key for normal (N) and reverse (S) polarity, and the plate boundary at the central mid-ocean ridge feature.