Computing device, computer instructions and method for jointly deghosting first and second 3-dimensional (3D) seismic vintages of a same subsurface. The method includes receiving the first 3D vintage; receiving the second 3D vintage, wherein the second 3D vintage is taken later in time than the first 3D vintage, over the same subsurface; jointly deghosting the first and second 3D vintages based on a common ghost-free model U0, a first vintage ghost-free model Ub, and a second vintage ghost-free model Um; and generating an image of the subsurface indicative of changes between the first and second 3D vintages based on the common ghost-free model U0.