Homework Due: Monday, September 12 at 3.00 p.m.   Read Robert Sheriff's article on the resolution of seismic reflections to answer the following questions: What occurs to the wave shape and amplitude as a bed becomes progressively thinner? What characteristics of the seismic signal can be used to determine the thickness of a bed although it may be too thin to resolve in the strict sense of the definition? Define and draw the First Fresnel Zone? Why do we not use parts of the reflection that come from beyond the 1/4 l -criterion.   Now read Widess' article on "how thin is a thin bed" to answer the following questions: 1. What effect does a thn bed have on the shape of a seismic reflection? Explain this coneptually and with equations.     For graduate students only: useful charts for graduate student to have: Study figure 4.20 which relates the empirical relation between density and sound velocity in common sediments. Note that the dotted line in the figure represents the plot of a famous empirical rule of thumb known as Gardner's rule. Use Gardner's rule and the equations we studied in class to plot the following graphs: 1. A plot of vertical resolution (Ralyleigh criterion) versus velocity. Show the different sediment types. Show your work and resultant equation. Summarize your conclusions. 2. A plot of the horizontal resolution (1/4 wavelength criterion) versus sound velocity in sediments and rocks. Indicate the different rock types. Assume a constant depth to your target reflector of 3000m. Show your work and resultant equation. Summarize your conclusions.