Figure 7

East position time series for station VNEV around the time of the 2010 Maule earthquake (see Fig. 1). (A) Sidereal filter. The coloured lines represent the six 24-hour time series preceding the mainshock. The black line is the average of the 6 time series after that they have been properly shifted and stacked. This is the sidereal filter that is going to be removed from the time series. (B) Position time series before applying the sidereal filter (blue) and after applying the sidereal filter (red). For this specific case, the standard deviation (or RMS) of the time series, calculated using the data before the mainshock, has been reduced from 8.6 mm to 3.5 mm. The vertical dashed line shows the time of the earthquake. Note that the coseismic offset has been removed.