A deep origin for the Tohoku earthquake?

So if I’m reading this summary in Eos right, there is a new study suggesting that there was significant deformation of the subducted plate in the lead up to the M9 2011 Tohoku earthquake occurred – enough mass was redistributed to measurably change the local gravity field.

There is a mechanical connection between the sinking/subducting plate and the surface – that’s what generates the ‘slab pull’ force that is one of the main drivers of plate tectonics. So a connection – whereby deformation deeper beneath Japan influenced the behavior of the the megathrust near the trench – is not implausible.

Cross-section through subduction zone at Japan Trench, illustrating the proposed sequence of events suggested by gravity data ahead of the 2010 Tohoku earthquake, where deformation in the deep slab preceded the shallow rupture at the trench.

However, the normal caveats about stuff like this apply:

finding a signal after the fact for one earthquake does not mean that we can reliably detect such signals before other earthquakes.
finding a potential signal does not mean we can predictably understand what it means.

In other words, we still can’t predict earthquakes.

[post collated from this Twitter thread]