- We enter the Difference between Initial Observation Data and the ten minute later Observation Data. This is an approximation to the derivative of the function OilSize[t] we hope to find, which is the size of the oil slick at time t.

Input := 

ID = Table[IL[[i]] - IO[[i]],{i,1,Length[IO]}]
Output =

{0.089, 0.08, 0.067, 0.043, 0.028, 0.016, 0.009}