Fig. 3: Surface deformation and geodetic modelling.
From: Volcanic crisis reveals coupled magma system at Santorini and Kolumbo
a, Map showing GNSS, OBSP and InSAR inferred surface displacements during diking between 23 February and 3 March 2025 and inverted source models. The joint geodetic inversion of InSAR, GNSS and OBSP locates the deflating mid-crustal magma reservoir (blue circle) beneath Kolumbo at 7.6 km depth with a 95% confidence interval (Supplementary Figs. 3 and 4) between 6.9–8.2 km and a volume decrease of 0.076 km3 (confidence interval 0.069–0.082 km3). The vertical inflating dike (red line) has a length of approximately 13 km and extends from 5 to 11.5 km in depth, aligning with the seismicity (black dots). The volume increase in the dike is 0.313 km3 (confidence interval 0.296–0.330 km3). b, Inflation between July 2024 and January 2025, measured by InSAR and GNSS with a modelled expanding magma reservoir at 3.8 km depth (confidence interval 2.4–5.4 km) and a volume change of 0.004 km3 (confidence interval 0.002–0.007 km3), averaging an influx rate of 0.26 m3 s−1 (confidence interval 0.13–0.48 m3 s−1). c, Time-dependent diking model during diking between 25 January and 24 February 2025 in five consecutive time windows along the inverted dike (a), on the basis of joint inversion of InSAR, GNSS and OBSP. The cumulative opening has been smoothed with a 0.2 km Gaussian filter. Seismicity along the profile is plotted as black dots. d, Magma flow rates (red and blue bars) of the deflation source beneath Kolumbo (outflow) and dike inflation (inflow) and cumulative volumes (red and blue lines). Vertical dashed lines mark the temporal phases of seismicity (Fig. 2).
