1. Explain the difference between reflection Air Gun Energy Source Hydrophone Receivers and refraction. 2. In the marine seismic acquisition example shown, you are interested in two events observed in the seismic trace that is recorded at the first hydrophone. seawater One is a first-order multiple (double velocity = 1478 m/s bounce) off the seafloor. The other is a water depth = 509 m 9% primary reflection from the sand/mud interface for which the energy ray-path seafloor has a takeoff angle of 9 degrees from vertical as shown. Assume horizontal rock layers and isotropic velocities. Which of the two events arrives at the sandstone hydrophone first - the primary or the velocity = 2793 m/s thickness - 1003 m multiple? Clearly show your calculations and include a simple drawing of the twoevent seismic trace. sand/mud 3. How long does it take for energy to travel directly from the air gun to the first mudstone hydrophone (no bounces)? velocity = 2240 m/s thickness = 373 m 4. What is the maximum takeoff angle at which seismic energy can reflect from CGG the sand/mud interface? Explain what Note: Illustration is not to scale.| happens to the energy for larger angles. 5. Explain the relative direction of travel for energy that is transmitted into the mudstone