On the graph in Fig. 5.5, plot points from the data table in pencil to show the travel time of each main seismic wave in relation to its distance from the epicenter (when recorded on the seismogram at the recording station). For example, the data for location 1 have already been plotted as red points on the graph. Recording station 1 was located 1800 km from the earthquake epicenter and the main waves had travel times of 3.8 minutes, 7.0 minutes, and 7.9 minutes. Plot points in pencil for data from all of the remaining recording stations in the data table and then examine the graph. Notice that your points do not produce a random pattern. They fall in discrete paths close to the three narrow black lines or curves already drawn on the graph. These black lines or curves were drawn by plotting many thousands of points from hundreds of earthquakes exactly as you just plotted your points. Explain why you think that your points and all of the points from other earthquakes occur along three discrete lines or curves. 019 Pearby B Study the three discrete, narrow black curves in Fig. 5.5. Label the curve that represents travel times of the P-waves. Label the curve that connects the points representing travel times of the s-waves. Label the line or curve that connects the points representing travel times of the surface waves. Why is the S-wave curve steeper than the P-wave curve? ducation Why do the surface wave data points that you plotted on Fig. 5.5 form a straight line whereas data points for P-waves and S-waves form curves? (Hint:P-and S-waves are body waves that travel through Earth's interior, whereas surface waves travel along Earth's surface.)