Geology and satellite imagery

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03-03-2020 11:24 AM
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MohamedAhmed_Hassan_Mohamed_Al
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How can I determine the faults and cracks in land surface using satellite image ?

I reach that bands combinations  7,6,2 is for geological feature but i don't know what to do to get the cracks and fault to be cleared 

can any one tell me what should do?

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DrewFaherty
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Landsat 8 band combination 7, 6, 2 is useful for distinguishing geologic units and structures, due to mineral responses in the shortwave infrared; however, faults are almost never discrete cracks at the surface, but are expressed as zones of rock deformation. The width of these zones varies from ten of centimeters to approximately 150 meters. while that sounds large, that's only five pixels in a Landsat image. One way to discern fault locations is to look for linear features in topography, or offsets in stream and drainage channels. Similarly, you can look for linear patterns in multispectral imagery, or areas where there are abrupt contrasts in surface composition. It might be helpful to look for academic papers on rock alteration or geothermal mapping using multispectral data. Also, you might test out classification or detection in areas with available geologic maps or fault maps. That way, you can evaluate your results. The United States Geological Survey is a great resource for digitized maps and vector layers.