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Documenting the preparation phase of giant earthquakes and retrieving pre-seismic signals of upcoming events is a crucial challenge. Over the short term, various deformation transients have been detected before large subduction events, emphasizing in particular the role of the slab pull in driving plate motions (eg, Bouchon et al., 2016; Bedford et al., 2020). Among them, we previously evidenced an anomalous gravity gradient signal during the months before the March 2011 Tohoku earthquake, likely originating from the solid Earth (Panet et al., 2018). We showed that it could reflect a broad deformation of the subducted slab prior to the event, generating the giant earthquake as the deformation propagated from depth to surface. Taking the example of the 2011 Tohoku earthquake, we conduct here a systematic and global retrospective analysis of time series of GRACE-reconstructed gravity gradients truncated in …