Wavelet is a appropriate tool for filtering local signals and usable for investigating the regional time variable effects in the gravity field. In this study, spherical wavelet modeling of regional and temporal variations of the Earth’s gravity field observed by GRACE is applied.  An inversion method is used in order to constrain the fault parameters of Maule’s 8.8-magnitude earthquake on 27^th Feb 2010 using gravimetric observations.

Gravity variations in directions of radius, latitude and longitude for wavelet with scale of 4 have determined 6, 10 and 4 microGal respectively which are similar to other studies. In addition, fault parameters such as length, width, depth, dip, strike and slip are computed using the changes in gravity and gravity gradient components. Moreover, the value of the seismic moment and moment magnitude are    and 8.88 Mw respectively that have a small differences with the values reported from USGS ( and 8.83 Mw).

In this study, a method for simulating co-seismic gravity gradient tensor of great earthquakes has been developed. We compare the results with the existing softwares. Moreover, gravity gradient changes of the 11 March, 2011, Tohoku earthquake has been calculated using GRACE data. The GRACE-derived gravity gradient changes as well as gravity change agee well with seismic model prediction. We use a set of the gravitational gradient tensor components (e.g. ΔVxx and ΔVxz, x and z refer to north and up directions, respectively) since they are more sensitive to small-scale signals and they reduce striping errors without using any de-striping filtering.