Question

3. [5 marks] The diagram to the right shows the paths that body waves would take to travel from the source to a series of seismic stations, A through G, if the Earth'so interior was homogeneous. Suppose that the seven seismic stations are spaced at equal distances apart on the Earth's surface and that the angle, ?, is equal to 90 degrees. If the source emits a P-wave at time zero, calculate the time taken for the wave to reach each of the seven stations. Assume that the speed of the body waves is 7.0 km/s. Summarize your answer in a table. Then draw a graph of distance travelled on the x-axis as a function of time on the y-axis (similar to the one shown on the lecture slides. BC Source Travel time to equally spaced stations station Distance Time (km) (min)

Answer 1

R e Go LSOB Simila station Ag(e Distande (K Tme (n) Imo (nin 3.41 433.1S 13 4227-5 7 O. 07 13-22 16.2 ia.oo TD SS-S371 STC 7880.67 Distance SpcedX time

100 50 0 5000 10000 Distance -50 100

Straight line