Supporting Information
Verdon et al. 10.1073/pnas.1302156110
−2000 −1000 0 1000 2000 3000
0 500 1000 1500 2000 2500 3000 3500
Depth (m)
tS - tP = 0.65s
tS - tP = 1s
Fig. S1. Loci of possible event locations based on differentialtS–tParrival times at the single functioning geophone. Loci fortS–tP=0.65 s andtS–tP=1 s are shown, corresponding to the mean arrival times of the main and secondary cluster, respectively. Possible loci describe a hemisphere, or“pudding bowl,” around the geophone. For the main cluster, the base of the bowl roughly corresponds to the depth of the reservoir. Given the small incidence angles for events from this cluster, it seems reasonable to suppose that they have originated from this area (rather than from shallower depths at greater lateral distance from the geophone). The second cluster, with higher incidence angles, is harder to constrain: events may have originated from above, in, or below the reservoir.
Verdon et al.www.pnas.org/cgi/content/short/1302156110 1 of 1