01682nas a2200181   4500000000100000000000100001008004100002260003300043653003600076100001400112700001200126245005700138856004800195300001000243490000700253520122600260020001401486       2003                            d  bSpringer Berlin / Heidelberg10aEarth and Environmental Science1 aC. Wunsch1 aD. Gunn00aA densely sampled core and climate variable aliasing  uhttp://dx.doi.org/10.1007/s00367-003-0125-2  a64-710 v233 aUndersampled records are susceptible to aliasing, in which a high frequency appears incorrectly as a lower one. We study the sampling requirements in a core taken from Rockall Trough using bulk density, P-wave velocity, and magnetic susceptibility as measured on an automated system. At 2-cm spacing (approximately 33 years in this core), all variables show a characteristic red-noise behavior, but with a spectral slope that is sufficiently weak so that significant aliasing appears to be present. P-wave velocity shows the largest potential corruption, probably owing to the weaker spatial averaging present in the sensor. Approximately 50\% of the apparent low-frequency energy is aliased in all variables at some frequencies in both quiet and active regions of the record. In this core, a sampling interval of 0.2 cm appears to be safe in both active and quiet portions of the core, aliasing little or no energy, except in the P-wave record. For cores of different duration, sampling interval, and measurement type, the considerations will be identical, the importance of the problem depending directly upon the shape of the overall spectrum describing the entire frequency (wavenumber) range of physical variability.  a0276-0460