Fig. 1. (a) Relative paleointensity records placed on their published age models. (b) The same records as in (a), after minor adjustment to synchronize the time scales near reversals (gray vertical lines). The standard polarity time scale is shown at the top of the figure.

Fig. 2. (a) Relative paleointensity records filtered with at 10 ky low-pass filter (all records are stacked at the top of the figure). (b) Low-pass filtering of the same records with a period of 25 ky. Alternating gray vertical bands demarcate variations common to most of the records, as evidenced by stacking the records (top).

Fig. 3. Smoothing of the individual paleointensity records by convolution with the Z-axis response function of a u-channel cryogenic magnetometer.

Fig. 4. Arithmetic stack of the records shown in Fig. 1b. The average paleointensity curve has been calculated after sampling the records at 0.1 ky intervals and normalizing the mean and variances of the initial data over their common time intervals (see text). Standard errors are indicated in gray. The number of cores used in the calculation is shown at the top of the figure.

Fig. 5. The same records as in Fig. 1a after additional adjustment to synchronize the time scales near the paleointensity minima depicted in Fig. 4 (gray vertical lines). The standard polarity time scale is shown at the top of the figure (SR = Santa Rosa, P = Punaruu, CM = Cobb Mountain).

Fig. 6. New stack obtained with the records dated with additional age tie-points shown in Fig. 5. (a) Stack and associated standard error. The one-sigma error interval is represented as gray shading and the two-sigma error is depicted as gray lines. The number of cores used in the calculation is shown at the top of the figure. (b) Jackknife results showing 15 stacks obtained from 15 subsets of records. Each subset was obtained by removing one record from the database.

Fig. 7. Absolute paleointensity and VDM records (solid dots) for polarity transitions from: (a) the Canary Islands (VDM, Brunhes/Matuyama, Valet et al., 1999). (b) Steens Mountain (paleointensity, 15 Ma, Prevot et al., 1985). (c) Kauai (VDM, 4 Ma, Bogue, 2000). (d) West Greenland (VDM, 60.9 Ma, Riisager and Abrahamsen, 2000). When available, virtual geomagnetic pole (VGP) latitudes have been plotted (open triangles). Gray arrows indicate the polarity transitions. The average paleointensity values (and associated one-sigma standard deviation) of the lava flows immediately preceding and following the transitions are represented by gray boxes.