The movie shows the electric field amplitudes as shaded colors for a CSEM transmitter being towed over the salt structure at Gemini Prospect, Gulf of Mexico. The left part of the figure shows the amplitude of the total horizontal electric field. The right side shows the ampitude of the vertical electric field. Notice the large vertical fields generated when the transmitter passes over the shallow linear ridge of salt. For a scale reference, the horizontal plane is 16 km wide and is located on the seabed. A transmission frequency of 0.25 Hz was modeled using the 3D CSEM finite difference code of Chester Weiss. The model consists of 1km of 0.3 Ohm-m seawater underlain by 0.5 Ohm-m conductive sediments. The seismically determined salt structure had resistivities set to 100 Ohm-m.

Click the link below to watch the Quicktime Movie. Note, you can let the movie play or drag the playhead around to see each frame individually.

GeminiCSEM_Exy_Ez.mov (12 MB, Quicktime 7 might be needed).