A sea level equation for seismic perturbations

Large earthquakes are a potentially important source of relative sea level variations, since
they can drive global deformation and simultaneously perturb the gravity field of the
Earth. For the first time, we formalize a gravitationally self–consistent, integral sea level
equation suitable for earthquakes, in which we account both for direct effects by the
seismic dislocation and for the feedback from water loading associated with sea level
changes. Our approach builds upon the well established theory first proposed in the realm
of glacio–isostatic adjustment modeling. The seismic sea level equation is numerically
implemented to model sea level signals following the 2004 Sumatra–Andaman earth-
quake, showing that surface loading from ocean water redistribution (so far ignored in
post–seismic deformation modeling) may account for a significant fraction of the total
computed post–seismic sea level variation.