Capturing the short-term dynamics of slow slip with subdaily GPS positions

The occurrence of slow slip events is strongly correlated with the activity of low frequency earthquakes (LFEs). While geodetic data captures the large-scale dynamics of aseismic slip, the rapidly evolving activity of low-frequency seismicity hints at slow slip dynamics on subdaily time scales. Previous studies have shown that large slow slip events are an intermittent sequence of short slip transients by decomposing the daily GPS position time series into tectonic loading and release, guided by a catalog of LFEs. These results imply that previous works likely underestimated the moment magnitude and overestimated the duration of major slow slip events. However, this approach is limited by the daily sampling rate of the GPS data, preventing access to the subdaily dynamics of slow slip. We estimate subdaily static and kinematic GPS solutions in the Guerrero (Mexico) subduction zone to capture surface motion at time scales shorter than a day. We develop a method to correct for multi-pathing noise from the multi-year kinematic position time series. We also incorporate the correction of common mode noise. Once processed to estimate positions at 6, 8 and 12 hour sampling rates, we decompose these GPS position time series with LFE activity to shed light on the subdaily dynamics of slow slip.