1. A non-transient computer-readable storage medium having computer-readable code, embodied on the computer-readable storage medium, for 4-D inversion of geophysical data for calculating distribution of subsurface material properties from geophysical data, the computer-readable code comprising program code for: (a) defining a geological structure continuously changing in time as a space-time model, defining measured data in space and time coordinates, and defining a reference space-time model vector (U) defined by Equation 2 and composed of a plurality of reference space model vectors (u) for a plurality of pre-selected reference times between start time and termination time for obtaining data so as to simulate a space-time model vector (P) defined by Equation 1; (b) approximating a numerical model for a geological structure space model at an arbitrary time using Taylor series of a numerical modeling for the plurality of reference space models, defining an objective inversion function to constrain each inversion in space and time domains, and obtaining the reference space-time model vector (U) from the measured data defined in space and time coordinates using the objective inversion function; and (c) obtaining the space-time model vector (P) from the reference space-time model vector (U) to calculate distribution of subsurface material properties changing in time; 
 P={p l ,. .. , p i ,. .. , p n },  Equation 1 where p i is a space model vector with respect to time i; 
 U={u l ,. .. , u i ,. .. , u n },  Equation 2 where u k is a reference space model vector with respect to the in (m<<n) number of pre-selected times τ k .