The backscattering strengths under Arctic sea ice for octave bands between 12 cps and 4 kc/sec were measured, using explosive sound sources. The measurements were made from a camp established in April 1962 on broken and pressure-packed one-year ice over the Canada Deep. For grazing angles between 5° and 14°, results show a dependence of scattering strengths both on grazing angle and on frequency. The dependence on grazing angle is small in frequencies above the 0.5- to 1-kc/sec band and large in the 12- to 25-cps band.