Forecast eruption times (left-hand panels) and mean (solid green) and 5 and 95 percentile scores (dashed green; right-hand panels) as a function of time for 500 synthetic earthquake sequences. IOL parameters are estimated using: (a) Forecast failure method (FFM); (b) Generalized Linear model (GLM); (c) Maximum-likelihood with p-value known (ML1) and (d) Maximum-likelihood method with p-value unknown (ML2). The true eruption time is shown by the horizontal dashed black line; forecast eruption time = t₁ is shown by the black dotted line for reference.