# assume to homogenous planar layers are exploded by a refraction survey,explain… 1 answer below »

1. assume to homogenous planar layers are exploded by a refraction survey, explain how head waves propagate through the surface using the relationship between raypaths and wavefronts.
1. assume that you are going to use a georadar to explore a wet sand layer in the subsurface. in order to define the reflector, you need a vertical resolution of 10 cm and you have a choice of radar frequency between 25 MHZ and 500 MHZ. what’s the minimum frequency to get a vertical resolution of 10 cm?
Document Preview:

assume to homogenous planar layers are exploded by a refraction survey, explain how head waves propagate through the surface using the relationship between raypaths and wavefronts. assume that you are going to use a georadar to explore a wet sand layer in the subsurface. in order to define the reflector, you need a vertical resolution of 10 cm and you have a choice of radar frequency between 25 MHZ and 500 MHZ. what’s the minimum frequency to get a vertical resolution of 10 cm? figure 1 below shows a multi-layer subsurface structure. assuming you run a seismic refraction survey. Draw an expected Time- distance curve and explain your answer. You don’t have to specify scales og time and distance on the curve Layer 1 1000 m/s Layer 2 1100 m/s Layer 3 1200 m/s Layer 4 500 m/s Layer 5 1300 m/s Layer 6 1500 m/s Layer 7 3000 m/s Figure 1 multi-layer subsurface structure figure 2 shows the seismic signal from a seismic refraction survey. X axis represent the offset distance with 5 feet space and y axis does the traveltime of each signal. the first arrivals are picked already at the locations indicated as (-) on each signal. assuming two homogeneous planar layer, calculate the seismic velocities of two layers and the thickness of top layer. the abandon gas station has a gas storage tank buried in the depth of 6 ft as shown in the figure 3. the station is still covered with a concrete surface with surrounding of top soil with vegetation. the dimension of storage tank is 8 ft diameter and 26 ft long to store 10000 gallons of gasoline. One day , Lee, manager of environmental department of the crazy city detected a level of gasoline at a river located to the east of station. he suspected that the gas storage tank might be leaking. he contacted you as a geophysical engineer to investigate the location of the storage tank and the propagation of the gasoline leakage with out any digging efforts. a) list possible options of geophysical survey and…