where h 0 is the depth in m.w.e. and I μ μ is the total muon flux per cm ⋅s. (The first term dominates for depths up to 1681.5 m.w.e.; below that, the second term dominates. Thus, for great depths, the factor of 4 mentioned above corresponds to a difference of 698 ln 4 ≈ 968 m.w.e.)