Figure 3
From: Quantifying uncertainties in the measurement of tephra fall thickness
The Fogo A data were analysed using a K-means cluster identification algorithm (see text) to interrogate spatial distribution patterns. A. The data is split into 10 clusters based on the spatial distribution of thickness measurements. Solid black circles represent the centre of each cluster with the coloured markers showing the data points that belong to each cluster. B. Percentage error determined as one standard deviation departure from mean of each cluster with distance. Here the effect of increasing the number of clusters in the analysis becomes more evident with percentage error greater with fewer clusters. C. The average percentage errors for different numbers of K-means cluster divisions decrease following a power-law trend.