Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions

TLDR

Recent revisions to the geomagnetic time scale suggest that the global plate motion model NUVEL‑1 must be adjusted to align with other motion estimates, including those from space geodetic measurements. The authors recalibrate NUVEL‑1 by multiplying its angular velocities by a constant factor of 0.9562, yielding the revised model NUVEL‑1A with updated velocity tables and uncertainties. Comparisons show that space‑geodetic rates are on average 6 ± 1 % slower than NUVEL‑1, but this discrepancy drops to less than 2 % when using the recalibrated NUVEL‑1A.

Abstract

Recent revisions to the geomagnetic time scale indicate that global plate motion model NUVEL‐1 should be modified for comparison with other rates of motion including those estimated from space geodetic measurements. The optimal recalibration, which is a compromise among slightly different calibrations appropriate for slow, medium, and fast rates of seafloor spreading, is to multiply NUVEL‐1 angular velocities by a constant, α, of 0.9562. We refer to this simply recalibrated plate motion model as NUVEL‐1A, and give correspondingly revised tables of angular velocities and uncertainties. Published work indicates that space geodetic rates are slower on average than those calculated from NUVEL‐1 by 6±1%. This average discrepancy is reduced to less than 2% when space geodetic rates are instead compared with NUVEL‐1A.