GAGE Plate Motion Calculator | Software (original) (raw)

Before using, please see: Overview Models Usage Notes References

Our Plate Motion Calculator calculates tectonic plate motion at any location on Earth using one or more plate motion models. You can specify:

• position in geographic or WGS-84 XYZ coordinates
• the tectonic plate (default is auto selection)
• plate motion model (default is GSRM v2.1)
• motion referenced either to a fixed plate or the NNR (no-net-rotation) frame of the selected model (default is NNR)
• optional site name
• multiple point entry in geographic or XYZ coordinates
• for advanced users: define your own angular velocity of attributed motion and/or your own reference angular velocity (specifying the angular velocity as an Euler pole of rotation plus the rotation rate about the Euler pole, or as cartesian coordiantes of the angular velocity vector)
• output format style (HTML table in local E-N frame or WGS-84 XYZ frame, or GMT psvelo)

The possible plate motion models that can be used are:

(Please see References at the end of this page.) The velocity uncertainties of each model are not taken into consideration and are assumed to be zero.

If you know of another plate motion model, possibly recently published, that uses a no-net-rotation (NNR) frame that you would like included in this calculator, please contactdata-helpearthscope.org.

It's much easier than it looks at first. For a single point, just enter the longitude and latitude and hit Submit. In this case, your point will then be located using the Autoplate selection, with motion referenced to the NNR frame of the ITRF2020 model. If, however, you feel that your coordinate is in some other plate or subplate (see Notes below), you can override the Auto plate selection and select some other plate and then resubmit. Likewise, if you want the motion relative to some other fixed plate, overide NNR as a reference. If you have coordinates in WGS-84 XYZ (cartesian) values, you can use those values as input. Try different models, or look at results from all models.

Once you get the feel for a single point entry, you can try multiple point entry. There are three important things to remember. First, each set of values for a location, whether in geographic or cartesian coordinates, must be separated from the others by a comma. Second, if you are using geographic coordinates, a height value (even if zero) must be supplied. Anything after the third coordinate (height if geographic, Z if cartesian) and before the comma is taken an optional site name. So, for geographic multiple point entry, your entry could look like:

-105.27 43.98 0 test site1, -104.45 42.02 0, -107.23 45.56 0,

Third, either all the multiple points need to be on the same tectonic plate, or else you should use the Auto plate selection, though (see Notes below) this means that the auto plate selection will only find the plates defined for NUVEL 1A.

Results for the geographic poles, 90°N and 90°S, will be correct but the east and north components of the velocity vector depend on the longitude given. To convince yourself, step back from the geographic pole a little, say, to 89.99°N or 89.99°S, at the same longitude and repeat the calculation.

If selected, the angular velocity parameters of NNR-NUVEL-1 by Argus and Gordon [1991] and NUVEL-1A by DeMets et al. [1994] are used. NUVEL-1A angular velocities are generally the same as NUVEL-1, except that the rate of rotations are on average about 4.4% slower due to an adjustment to the magnetic anomaly time scale. For the Juan de Fuca and Philippine Sea angular velocities of NUVEL-1A, the more recent recalibrated angular velocities are used.

Care must be taken when comparing a specified plate between different models, because which plates are defined or have defined angular velocities varies from model to model. The Auto plate selection of the calculator uses 15 plate boundaries corresponding to the NUVEL 1A model (bold in the table below). See map of 15 plate boundaries and ASCII files of these boundaries' coordinates. Using the table below, then, the Antarctica plate (AN) of NUVEL 1 corresponds to the combined Antarctica (AN) and Scotia (ST) plate of NUVEL 1A. Likewise, the combined Australia (AU) and Capricorn (CP) plates of the GSRM correspond to the Australia (AU) plate of the other models. In certain models, some plates have no defined angular velocity, e.g. the India (IN) plate in the APKIM2000 model. This leads to two important points:

Caveat emptor!

• If you or the Auto plate selection selects a plate for your location that is not accounted for in the selected model, that plate is assumed to have a zero angular velocity. Likewise, if you select a fixed-plate reference where that plate is not accounted for in the selected model, that fixed-plate reference is assumed to have a zero angular velocity with respect to the NNR frame. Therefore, make sure that the selected plate and fixed-plate reference (if not NNR) are defined for the selected model before using the results.
• If you enter your own Euler vector for an angular velocity of attributed motion and select NNR as the reference (for any model), by definition this is exactly the same as setting the reference angular velocity to a zero Euler vector.

Another subtle point is that the plate motion models apply only on those places on a plate undergoing rigid body rotation — which is especially important to keep in mind for the GSRM. If you are attempting to model the motion in a plate boundary zone which is undergoing strain deformation (i.e. not just a simple rigid body rotation), then the rigid body motion model is only an approximation to the actual motion.

* Besides the listed plates and microplates for the GSRM v2.1 model, there are 26 additional microplates along what are usually considered plate boundary regions. The user is advised to find the location of these microplates in the GSRM v2.1 model before using them.

Note 1: The MORVEL models and the GSRM v2.1 model also contain many small plates, many defined in Bird [2003], which are typically on or near the plate boundaries between major plates, which are too numerous to list in the above table.

Note 2: Full plate names, including those for the many small plates mentioned in Note 1 above, are in the Tectonic Plate and Reference pulldown menus.

And what is a "no-net_rotation" (aka NNR) frame? By definition it is the reference frame for a given model of plate motion that yields zero for the integral of the vector cross-productv x r over the surface of the Earth.

HS2-NUVEL1A and HS3-NUVEL1A: Technically these models are not published in a NNR frame, since these represent the plate motions relative to fixed "hotspot" frames. In order to make this calculator function more logically, however, these models are also provided here in a NNR frame whereby the following "hotspot frame - NNR frame" rotations have been applied:

| | latitude ofEuler pole | longitude ofEuler pole | rotation rate | | | ------------------------ | ---------------------- | ------------- | ------------ | | HS2-NUVEL1A | –49.18° | 65.00° | 0.3194°/Myr | | HS3-NUVEL1A | –55.916° | 70.00° | 0.43607°/Myr |

From this calculator, you should obtain about the same site motion for the NUVEL 1A model in the NNR frame and HS2-NUVEL1A model rotated into the NNR frame; the difference is mainly due to rounding errors using the various model parameters tabulated in different units, including the parameters for the "HS2 hotspot frame - NNR frame" rotation above.

Altamimi, Z., Métivier, L., Rebischung, P., Collilieux, X., Chanard, K., & Barnéoud, J. (2023). ITRF2020 plate motion model. Geophysical Research Letters, 50, e2023GL106373. https://doi.org/10.1029/2023GL106373.

Altamimi, Z., P. Sillard, and C. Boucher, ITRF2000: A new release of the International Terrestrial Reference Frame for earth science applications, J. Geophys. Res., 107(B10), 2214,https://doi.org/10.1029/2001JB000561, 2002; see alsotn31_270.pdf.

Altamimi, Z., L. Métivier, and X. Collilieux, ITRF2008 plate motion model, J. Geophys. Res., 117(B07402), 14 pp.,https://doi.org/10.1029/2011JB008930, 2012.

Altamimin, Z., P. Rebischung, L. Métlvler, and X. Collilleux, ITRF2014: A new release of the International Terrestrial Reference Frame modeling nonlinear station motions, J. Geophys. Res., 121, 6109-6131,https://doi.org/10.1002/2016JB013098, 2016.

Argus, D.F. and R.G. Gordon, No-net-rotation model of current plate velocities incorporating plate motion model NUVEL-1, Geophys. Res. Lett., 18, 2039-2042,https://doi.org/10.1029/91GL01532, 1991.

Argus, D.F., R.G. Gordon, and C.DeMets, Geologically current motion of 56 plates relative to the no-net-rotation reference frame,Geochemistry, Geophysics, Geosystems, 12, No. 11, 13 pp.,https://doi.org/10.1029/2011GC003751, 2011.

Argus, D.F., R.G. Gordon, M.B. Heflin, C. Ma, R.J. Eanes, P. Willis, W.R. Peltier, and S.E. Owen, The angular velocities of the plates and the velocity of the Earth's centre from space geodesy,Geophys. J. Int., 18, 1-48,https://doi.org/10.1111/j.1365-246X.2009.04463.x, 2010; Don Argus kindly provided us with the GEODVEL NNR angular velocities.

Bird, P., An updated digital model of plate boundaries,Geochemistry, Geophysics, Geosystems, 4, No. 3, 52 pp.,https://doi.org/10.1029/2001GC000252, 2003; see also2001GC000252.pdf.

DeMets, C., R.G. Gordon, D.F. Argus, and S. Stein, Current plate motions,Geophys. J. Int., 101, 425-478,https://doi.org/10.1111/j.1365-246X.1990.tb06579.x, 1990.

DeMets, C., R.G. Gordon, D.F. Argus, and S. Stein, Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions, Geophys. Res. Lett., 21, 2191-2194,https://doi.org/10.1029/94GL02118, 1994.

DeMets, C., R.G. Gordon, and D.F. Argus, Geologically current plate motions,Geophys. J. Int., 181, 1-80,https://doi.org/10.1111/j.1365-246X.2009.04491.x, 2010; see also Erratum, Geophys. J. Int., 0, 1-1,https://doi.org/10.1111/j.1365-246X.2011.05186.x, 2011.

Drewes, H., Combination of VLBI, SLR, and GPS determined station velocities for actual plate kinematic and crustal deformation models, Geodynamics, M. Feissel (Ed.), IAG Symposia, Springer,https://doi.org/10.1007/978-3-642-72245-5_59, 1998.

Drewes, H., The Actual Plate Kinematic and Crustal Deformation Model APKIM2005 as basis for a non-rotating ITRF,Geodetic Reference Frames, H. Drewes (Ed.), IAG Symposia, 134, 95-99, Springer,https://doi.org/10.1007/978-3-642-00860-3_15, 2009.

Drewes, H., and D. Angermann, The Actual Plate Kinematic and Crustal Deformation Model 2000 (APKIM2000) as a Geodetic Reference System, AIG 2001 Scientific Assembly, Budapest, 2-8 Sept 2001; see alsoDS_APKIM.pdf.

Gripp, A.E., and R.G. Gordon, Current plate velocities relative to the hopspots incorporating the NUVEL-1 global plate motion model, Geophys. Res. Lett., 17, 1109-1112,https://doi.org/10.1029/GL017i008p01109, 1990.

Gripp, A.E., and R.G. Gordon, Young tracks of hotspots and current plate velocities, Geophys. J. Int., 150, 321-361,https://doi.org/10.1046/j.1365-246X.2002.01627.x, 2002.

Kreemer, C., Global Strain Rate Map Project; Corné Kreemer kindly provided NNR angular velocities for version 1.2, May 2004; see also Kreemer, C., W.E. Holt, and A.J. Haines, An integrated global model of present-day plate motions and plate boundary deformation, Geophys. J. Int., 154, 8-34,https://doi.org/10.1046/j.1365-246X.2003.01917.x, 2003.

Kreemer, C., G. Blewitt, and E.C. Klein, A geodetic plate motion and Global Strain Rate Model,Geochemistry, Geophysics, Geosystems, 15, 3849-3889,https://doi.org/10.1002/2014GC005407, 2014.

Prawirodirdjo, L., and Y. Bock, Instantaneous global plate motion model from 12 years of continuous GPS observations,J. Geophys. Res., 109, B08405,doi:10.1029/2003JB002944, 2004; see alsoSOPAC Pole Rotation Tables for the latest and earlier monthly solutions of the CGPS model parameters.

Sella, G.F., T.H. Dixon, and A. Mao, REVEL: A model for recent plate velocities from space geodesy,J. Geophys. Res., 107, B4,https://doi.org/10.1029/2000JB000033, 2002.

• Lamont-Doherty Plate Velocity Calculator for NUVEL-1
  (another variation for points near spreading ridges:Ridge Spreading Rate Calculator, also using NUVEL-1)
• University of Tokyo Plate Motion Calculator for NUVEL-1, NUVEL-1A, NUVEL-1 NNR, NUVEL-1A NNR, and HS3-NUVEL1
• Rice University Plate Motion Calculator for HS3-NUVEL1A
• University of Wisconsin-Madison Plate Motion Calculator for MORVEL and NNR-MORVEL56 (25 large plates in MORVEL and MORVEL56), and**NNR-MORVEL56 Plate Motion Calculator** (all 56 plates in MORVEL56)

Last modified: 2024-06-11 17:52:23 America/Denver