Stokes parameters of the resonance Sr I 4607 Å line were observed with the solar THEMIS telescope in December 2002, close to the limb of the sun at the North pole. They are interpreted in terms of turbulent magnetic field. The Interpretation requires a non-LTE radiative transfer calculations of the Stokes parameters. The contributions of depolarizing isotropic collisions with neutral hydrogen and inelastic collisions with electrons as well as the radiative processes are taken into account in the statistical equilibrium equations in order to identify weak magnetic fields by their depolarizing Hanle effect. The values of depth-dependent magnetic field, derived from observations at different distances from the solar limb, are given. These observations and the magnetic field results are in agreement with other measurements also obtained with THEMIS, and interpreted by using a different formalism (Faurobert M., Arnaud J., Vigneau J., Frisch H., 2001, A&A 378, 627).