Table S2-a 
# Velocity model used to locate tremor sources in the southern Central Range

# This is the same velocity model used by Tang et al. (GRL, 2010) to locate LFEs in the same region 
# Vp  Vp/Vs Vs  dep_range
 3.82 1.74 2.20  0.0  2.0
 4.93 1.68 2.93  2.0  4.0
 5.51 1.70 3.24  4.0  6.0
 5.63 1.70 3.31  6.0  9.0
 5.83 1.76 3.31  9.0 13.0
 5.99 1.75 3.42 13.0 17.0
 6.06 1.75 3.46 17.0 21.0
 6.13 1.75 3.50 21.0 25.0
 6.25 1.71 3.65 25.0 30.0
 6.54 1.73 3.78 30.0 35.0
 7.03 1.75 4.02 35.0 50.0
 8.00 1.74 4.60 50.0 70.0
 8.34 1.73 4.82 70.0 80.0
# The units of Vp, Vp/Vs, and Vs are in km/s  
# The unit of depth_range is in km

Table S2-b
# Velocity model used to locate tremor sources in the northern Central Range
 3.88 1.81 2.14  0.0  2.0
 4.50 1.70 2.65  2.0  4.0
 4.89 1.68 2.91  4.0  6.0
 5.18 1.69 3.07  6.0  9.0
 5.65 1.69 3.34  9.0 13.0
 5.88 1.69 3.48 13.0 17.0
 6.07 1.70 3.57 17.0 21.0
 6.36 1.71 3.72 21.0 25.0
 6.62 1.73 3.83 25.0 30.0
 6.96 1.73 4.02 30.0 35.0
 7.36 1.73 4.25 35.0 50.0
 7.91 1.73 4.57 50.0 70.0
 8.14 1.73 4.71 70.0 80.0
# The units of Vp, Vp/Vs, and Vs are in km/s  
# The unit of depth_range is in km