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.

We determine best-fitting Euler vectors, closure-fitting Euler vectors, and a new global model (NUVEL-1) describing the geologically current motion between 12 assumed-rigid plates by inverting plate motion data we have compiled, critically analysed, and tested for self-consistency. We treat Arabia, India and Australia, and North America and South America as distinct plates, but combine Nubia and Somalia into a single African plate because motion between them could not be reliably resolved. The 1122 data from 22 plate boundaries inverted to obtain NUVEL-1 consist of 277 spreading rates, 121 transform fault azimuths, and 724 earthquake slip vectors. We determined all rates over a uniform time interval of 3.0m.y., corresponding to the centre of the anomaly 2A sequence, by comparing synthetic magnetic anomalies with observed profiles. The model fits the data well. Unlike prior global plate motion models, which systematically misfit some spreading rates in the Indian Ocean by 8-12mmyr-', the systematic misfits by NUVEL-1 nowhere exceed -3 mm yr-'. The model differs significantly from prior global plate motion models. For the 30 pairs of plates sharing a common boundary, 29 of 30 P071, and 25 of 30 RM2 Euler vectors lie outside the 99 per cent confidence limits of NUVEL-1. Differences are large in the Indian Ocean where NUVEL-1 plate motion data and plate geometry differ from those used in prior studies and in the Pacific Ocean where NUVEL-1 rates are systematically 5-20 mm yr-' slower than those of prior models. The strikes of transform faults mapped with GLORIA and Seabeam along the Mid-Atlantic Ridge greatly improve the accuracy of estimates of the direction of plate motion. These data give Euler vectors differing significantly from those of prior studies, show that motion about the Azores triple junction is consistent with plate circuit closure, and better resolve motion between North America and South America. Motion of the Caribbean plate relative to North or South America is about 7mmyr-' slower than in prior global models. Trench slip vectors tend to be systematically misfit wherever convergence is oblique, and best-fitting poles determined only from trench slip vectors differ significantly from their corresponding closure-fitting Euler vectors. The direction of slip in trench earthquakes tends to be between the direction of plate motion and the normal to the trench strike. Part of this bias may be due to the neglect of lateral heterogeneities of seismic velocities caused by cold subducting slabs, but the larger part is likely caused by independent motion of fore-arc crust and lithosphere relative to the overriding plate.

S U M M A R YWe describe best-fitting angular velocities and MORVEL, a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface. Seafloor spreading rates and fault azimuths are used to determine the motions of 19 plates bordered by mid-ocean ridges, including all the major plates. Six smaller plates with little or no connection to the mid-ocean ridges are linked to MORVEL with GPS station velocities and azimuthal data. By design, almost no kinematic information is exchanged between the geologically determined and geodetically constrained subsets of the global circuit-MORVEL thus averages motion over geological intervals for all the major plates. Plate geometry changes relative to NUVEL-1A include the incorporation of Nubia, Lwandle and Somalia plates for the former Africa plate, Capricorn, Australia and Macquarie plates for the former Australia plate, and Sur and South America plates for the former South America plate. MORVEL also includes Amur, Philippine Sea, Sundaland and Yangtze plates, making it more useful than NUVEL-1A for studies of deformation in Asia and the western Pacific. Seafloor spreading rates are estimated over the past 0.78 Myr for intermediate and fast spreading centres and since 3.16 Ma for slow and ultraslow spreading centres. Rates are adjusted downward by 0.6-2.6 mm yr −1 to compensate for the several kilometre width of magnetic reversal zones. Nearly all the NUVEL-1A angular velocities differ significantly from the MORVEL angular velocities. The many new data, revised plate geometries, and correction for outward displacement thus significantly modify our knowledge of geologically current plate motions. MORVEL indicates significantly slower 0.78-Myr-average motion across the Nazca-Antarctic and Nazca-Pacific boundaries than does NUVEL-1A, consistent with a progressive slowdown in the eastward component of Nazca plate motion since 3.16 Ma. It also indicates that motions across the Caribbean-North America and Caribbean-South America plate boundaries are twice as fast as given by NUVEL-1A. Summed, least-squares differences between angular velocities estimated from GPS and those for MORVEL, NUVEL-1 and NUVEL-1A are, respectively, 260 per cent larger for NUVEL-1 and 50 per cent larger for NUVEL-1A than for MORVEL, suggesting that MORVEL more accurately describes historically current plate motions. Significant differences between geological and GPS estimates of Nazca plate motion and Arabia-Eurasia and India-Eurasia motion are reduced but not eliminated when using MORVEL instead of NUVEL-1A, possibly indicating that changes have occurred in those plate motions since 3.16 Ma. The MORVEL and GPS estimates of Pacific-North America plate motion in western North America differ by only 2.6 ± 1.7 mm yr −1 , ≈25 per cent smaller than for NUVEL-1A. The remaining difference for this plate pair, assuming there are no unrecognized systematic errors and no measurable change in Pacific-North America motion ...

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Summary Plate motions relative to the hotspots over the past 4 to 7 Myr are investigated with a goal of determining the shortest time interval over which reliable volcanic propagation rates and segment trends can be estimated. The rate and trend uncertainties are objectively determined from the dispersion of volcano age and of volcano location and are used to test the mutual consistency of the trends and rates. Ten hotspot data sets are constructed from overlapping time intervals with various durations and starting times. Our preferred hotspot data set, HS3, consists of two volcanic propagation rates and eleven segment trends from four plates. It averages plate motion over the past ≈5.8 Myr, which is almost twice the length of time (3.2 Myr) over which the NUVEL‐1A global set of relative plate angular velocities is estimated. HS3‐NUVEL1A, our preferred set of angular velocities of 15 plates relative to the hotspots, was constructed from the HS3 data set while constraining the relative plate angular velocities to consistency with NUVEL‐1A. No hotspots are in significant relative motion, but the 95 per cent confidence limit on motion is typically ±20 to ±40 km Myr−1 and ranges up to ±145 km Myr−1. The uncertainties of the new angular velocities of plates relative to the hotspots are smaller than those of previously published HS2‐NUVEL1 (Gripp & Gordon 1990), while being averaged over a shorter and much more uniform time interval. Nine of the fourteen HS2‐NUVEL1 angular velocities lie outside the 95 per cent confidence region of the corresponding HS3‐NUVEL1A angular velocity, while all fourteen of the HS3‐NUVEL1A angular velocities lie inside the 95 per cent confidence region of the corresponding HS2‐NUVEL1 angular velocity. The HS2‐NUVEL1 Pacific Plate angular velocity lies inside the 95 per cent confidence region of the HS3‐NUVEL1A Pacific Plate angular velocity, but the 0 to 3 Ma Pacific Plate angular velocity of Wessel & Kroenke (1997) lies far outside the confidence region. We show that the change in trend of the Hawaiian hotspot over the past 2 to 3 Myr has no counterpart on other chains and therefore provides no basis for inferring a change in Pacific Plate motion relative to global hotspots. The current angular velocity of the Pacific Plate can be shown to differ from the average over the past 47 Myr in rate but not in orientation, with the current rotation being about 50 per cent faster (1.06 ± 0.10 deg Myr−1) than the average (0.70 deg Myr−1) since the 47‐Myr‐old bend in the Hawaiian–Emperor chain.

[1] NNR-MORVEL56, which is a set of angular velocities of 56 plates relative to the unique reference frame in which there is no net rotation of the lithosphere, is determined. The relative angular velocities of 25 plates constitute the MORVEL set of geologically current relative plate angular velocities; the relative angular velocities of the other 31 plates are adapted from Bird (2003). NNR-MORVEL, a set of angular velocities of the 25 MORVEL plates relative to the no-net rotation reference frame, is also determined. Incorporating the 31 plates from Bird (2003), which constitute 2.8% of Earth's surface, changes the angular velocities of the MORVEL plates in the no-net-rotation frame only insignificantly, but provides a more complete description of globally distributed deformation and strain rate. NNR-MORVEL56 differs significantly from, and improves upon, NNR-NUVEL1A, our prior set of angular velocities of the plates relative to the no-net-rotation reference frame, partly due to differences in angular velocity at two essential links of the MORVEL plate circuit, Antarctica-Pacific and Nubia-Antarctica, and partly due to differences in the angular velocities of the Philippine Sea, Nazca, and Cocos plates relative to the Pacific plate. For example, the NNR-MORVEL56 Pacific angular velocity differs from the NNR-NUVEL1A angular velocity by a vector of length 0.039 ± 0.011°a −1 (95% confidence limits), resulting in a root-mean-square difference in velocity of 2.8 mm a −1. All 56 plates in NNR-MORVEL56 move significantly relative to the no-net-rotation reference frame with rotation rates ranging from 0.107°a −1 to 51.569°a −1.Components: 6300 words, 5 figures, 5 tables.

NUVEL‐1 is a new global model of current relative plate velocities [DeMets et al., 1990], which differ significantly from those of prior models. Here we incorporate NUVEL‐1 into HS2‐NUVEL1, a new global model of plate velocities relative to the hotspots. HS2‐NUVEL1 was determined from the hotspot data and errors used by Minster and Jordan [1978] to determine AM1‐2, which is their model of plate velocities relative to the hotspots. AM1‐2 is consistent with Minster and Jordan's relative plate velocity model RM2. Here we compare HS2‐NUVEL1 with AM1‐2 and examine how their differences relate to differences between NUVEL‐1 and RM2. HS2‐NUVEL1 plate velocities relative to the hotspots are mainly similar to those of AM1‐2. Minor differences between the two models include the following: (1) in HS2‐NUVEL1 the speed of the partly continental, apparently non‐subducting Indian plate is greater than that of the purely oceanic, subducting Nazca plate; (2) in places the direction of motion of the African, Antarctic, Arabian, Australian, Caribbean, Cocos, Eurasian, North American, and South American plates differs between models by more than 10°; (3) in places the speed of the Australian, Caribbean, Cocos, Indian, and Nazca plates differs between models by more than 8 mm/yr. Although 27 of the 30 RM2 Euler vectors differ with 95% confidence from those of NUVEL‐1, only the AM1‐2 Arabia‐hotspot and India‐hotspot Euler vectors differ with 95% confidence from those of HS2‐NUVEL1. Thus, substituting NUVEL‐1 for RM2 in the inversion for plate velocities relative to the hotspots changes few Euler vectors significantly, presumably because the uncertainty in the velocity of a plate relative to the hotspots is much greater than the uncertainty in its velocity relative to other plates.

Cenozoic global plate motions relative to the hot spots are investigated and compared to plate motions in a mean‐lithosphere reference frame. Plate motions were analyzed over six time intervals divided by ages (10, 25, 43, 48, and 56 Ma) chosen, as much as possible, to coincide with key plate reorganizations. Alternative motion circuits and rotational parameters were considered and evaluated with paleomagnetic data from the Pacific and North American plates. The circuit found to be in best agreement with the paleomagnetic data is one in which the hot spots in the Atlantic region are assumed to be fixed relative to the hot spots in the Pacific region. Throughout the Cenozoic, the hot spot and mean‐lithosphere reference frames have been in continual, slow relative motion. The rate of motion is nonuniform, however, most of the motion having occurred during the middle Cenozoic. The net Cenozoic rotation of the lithosphere relative to the hot spots is described by a right‐handed rotation of 7° about a Euler pole at 46°S, 87°E, which yields a 5° displacement of the north poles of the two reference frames. This motion is small enough that inferences drawn about plate speeds in one reference frame should be valid in the other. Analysis of the global motions resulting from our preferred model showed that many characteristics of current plate motions have persisted throughout the Cenozoic. Plate speeds correlate with latitude, plates moving faster near the equator than near the poles throughout the Cenozoic. As at present, continental plates (except for the Indian plate) moved slower than oceanic plates throughout the Cenozoic. Even the structure of the velocity fields as revealed in a contour of root‐mean‐square velocities in equatorial bands persists throughout the Cenozoic. The migration of the paleomagnetic axis over time is also compared to the hot spot and mean‐lithosphere reference frames. The paleomagnetic axis has shifted 5°–10° relative to the hot spot frame, and a lesser amount relative to the mean‐lithosphere frame.