In the textbook Table 4.1 provides a generic marine seismic model. Instead of going through the exercise as outlined in problem 8 of shearer, only consider the P-waves and input this model into the MATLAB script I provided called thetafun.m and do the following.

4. Thetafun (25 pts)

In the textbook Table 4.1 provides a generic marine seismic model. Instead of going through the exercise as outlined in problem 8 of shearer, only consider the P-waves and input this model into the MATLAB script I provided called thetafun.m and do the following.

(a) The code makes a plot of the velocity model, so include a plot of the velocity model to ensure that it is input correctly. Note that the model is not a layer-cake model, but should include linear velocity gradients.

(b) Using your plot of the Theta function and the ray paths drawn by the program, identify how many arrivals there are, what their travel-times are, and what the arrivals actually are (e.g., direct ray, refracted ray below x, reflected ray off of x, etc.) for a receiver at x = 20 km, and x = 40 km.

(c) Are all of the rays identified in part (b) physical?