Fig. 2: Tephra thickness with distance from vent.
From: The radius of the umbrella cloud helps characterize large explosive volcanic eruptions
a The plot shows the minimum and maximum range (shaded area) of erupted mass (M), disk height (H), and umbrella cloud radius (R) that can explain the mapped deposit of the climactic phase of the Pululagua 2045 BP eruption. The red dashed line shows the best-fit model. Thickness of the deposit was obtained from mass/area using a bulk deposit density of 1000 kg m−3 26. The χ2—criterion for the goodness of fit is 9300 and 3600 for the maximum and minimum of the estimated range of ESPs, respectively, while for the best fit is ~1800 (a value closer to 0 indicating a better agreement between observed and modeled data). b The relationship between the observed and modeled tephra deposit thickness. The dashed line represents a correlation of 1 and the solid line represents the best fit between the observed and modeled data. Both root mean square error (RMSE) and the coefficient of determination (r2) indicate the quality of fit between the modeled and observed thicknesses.
