Figure 5: Probability of a new volcano forming during the next 10,000 years varies in the YMR because of the tendency for volcanoes to cluster. Here the logarithm of probability of a volcano forming within a 8 km² area during the next 10,000 years is contoured using 9 nearest-neighbors, and all volcanoes in data set 1 (a) 8 nearest-neighbors and all volcanoes in data set 1 formed less than 5 Ma (b). In these and all of the following maps, the solid triangles indicate the positions of volcanoes used in the calculation (data set 1 or 2) and open triangles indicate the positions of volcanoes that are part of the data set, but are not included in the calculation because of their age. The location of the proposed repository (solid rectangle) is indicated. The contour interval is 0.25 log(P[N=1, 10,000 yr]) (e.g., -4 is a probability of 1 x 10^-4 of a new volcano forming within an 8 km² area in 10,000 years). Map coordinates are in Universal Transverse Mercator (km), Clarke 1866 projection.