Figure 7

POLA-01 (top), POLA-03 (middle) and POLA-04 (bottom) pressure feature (left) and local significance (right) as a function of time. The Gaussian-like feature has a fixed sigma (from top to bottom) of 3, 5, 8, 10, 15 and 20 min, respectively. The yellow, orange and green horizontal lines show the 3, 4 and 5 global significance sigma, respectively. The vertical dotted line corresponds to the eruption time.