Fig. 7

a Coseismic velocity reduction associated with the 24 May 2013 M 5.7 Greenville earthquake (dashed red line). Blue circles and orange squares are dv/v for stack of 5 days in a frequency range of 0.5–0.9 Hz from two different coda windows: (1) −50 to −20 s and 20 to 50 s and (2) the inter-station distance dependent, respectively. Black line represents the cumulative number of earthquakes that occurred within 10 km from station LEL from March 1, 2013. Also shown in the modeled precipitation (gray bars) at Lassen Peak. b The postseismic velocity recovery following the 2013 Greenville earthquake. Black line is dv/v for stack of 30 days in a frequency range of 0.1–0.9 Hz with the coda window ranging from −50 to −20 s and 20 to 50 s. Red line is a synthetic velocity change modeled by a logarithmic velocity recovery with the median model parameters. Note that the velocity changes were normalized by the maximum velocity drop. Also shown is the seismic velocity change (gray line) at the San Andreas fault, induced by the 2003 M 6.6 San Simeon earthquake (Brenguier et al. 2008a) and its synthetic velocity change (blue line). Note that we only show Brenguier’s result in the first 285-day postseismic period to avoid another velocity reduction due to the 2004 M 6.0 Parkfield earthquake. c Distribution of the relaxation time (τ) from the bootstrap analysis with 1000 subsample datasets. The black line indicates the median value (250 days), and dashed lines are the 95th confidence interval (213–294 days)