Carbon-14 dating and percent CaCO3 in late Pleistocene sediments suggest that deep-sea sedimentation rates vary cyclically and that this cyclicity is related to climate. Sedimentation rate variability leads to nonlinearity in the time-depth mapping function. This nonlinearity can have profound affects on signal spectra, leading to the development of harmonics and intermodulation tones. These distortion effects in the spectra give a direct indication of the degree of nonlinearity, thereby providing a tool for realigning time and depth scales. A tuning technique is developed which assumes a direct link between climate (as measured in Δ18O from planktonic foraminifer tests) and sedimentation rates. A criterion of ''spectral simplicity,'' as quantified in the varimax norm, is used to demodulate the input spectrum. Application of this technique to an equatorial Pacific piston core (ERDC 84) found peak glacial sedimentation rates to be 30% higher than peak interglacial rates, a figure in good agreement with 14C--based estimates from the same area. This technique is compatible with other time scale tuning techniques such as those using orbital parameters and, in combination with these other techniques, provides a method for fine-tuning any late Pleistocene record.