The elastic moduli of polycrystalline ringwoodite, (Mg-0.91 Fe-0.09)(2)SiO4, were measured up to 470 K by means of the resonant sphere technique. The adiabatic bulk (K-S) and shear (mu) moduli were found to be 185.1(2) and 118.22(6) GPa at room temperature, and the average slopes of dK(S)/dT and dmu/dT in the temperature range of the study were determined to be -0.0193(9) and -0.0148(3) GPa/K, respectively. Using these results, we estimate seismic wave velocity jumps for a pure olivine mantle model at 520 km depth. We find that the jump for the S-wave velocity is about 1.5 times larger than that for the P-wave velocity at this depth. This suggests that velocity jumps at the 520 km discontinuity are easier to detect using S-waves than P-waves. (C) 2004 Elsevier B.V. All rights reserved.