Figure 4From: Linear stability of plane Poiseuille flow in an infinite elastic medium and volcanic tremorsDistribution of phase velocities in the complex plane. Red and blue lines respectively indicate the zero contour lines of the real and imaginary parts of the determinant of the 5 × 5 matrix representing the boundary conditions at x = 1. The solution, c, is represented by an intersection of red and blue lines and shown by a black dot. (a) The symmetric case where L = 20, β = 1.5,α/β= 3 , ϱ = 1, S = 10-3, δ = 0.5, and M = 0, 0.4, and 0.8. The gray shading shows the range of 0 ≤ Re(c) ≤ M. (b) Same but for the antisymmetric case. Two solutions, denoted by A and B, originating from the antisymmetric Krauklis waves are observed around Re(c) = ±1.3. Close-ups of these solutions are shown on the right-hand side.Back to article page