Science behind sensing hydrocarbon seepage using X-band radar

It is well established that hydrocarbons seep from oil and gas accumulations and reach the surface, though the processes involved are debated. The concern for explorationists has been which methods are best at mapping the seepage at the surface, and thus most useful to interpreting the subsurface location of the leaking accumulation. Methods have historically concentrated on measurements taken in the earth, primarily in the soil, but beginning as early as the 1970s atmospheric measurements were introduced. In 1972 Robert Owen and J.M. Busby were issued a patent for mapping hydrocarbons (implied to be methane) in the atmosphere using microwave radar in the X-band (8,000--12,000 MHz). In the first of two articles the authors show that the original theory proposed for radar sensing of seepage is incorrect. There is, though, a plausible scientific explanation. The second article will examine, based on a large radar survey, how well the method appears to work.