This "Plate Motion Calculator" calculates the relative and absolute plate motion direction and speed at any point on the earth. The prototype of web-based plate motion calculator was developed by K. Tamaki. This calculator is a revised version by K. Okino using perl-CGI script.
Method of Calculation: Select plate motion model, plate (or plates) and input latitude and longitude of the point, then press the "Execute calculation" button.
Plate Model: (see references below)
Moving Plate:
Fixed Plate: (not used in NNR models)
Latitude[deg]: (North: positive, South : negative (ex. -15.5))
Longitude[deg]:(East: positive, West: negative (ex. -116.5))
References of Models:
- NUVEL-1:(relative motion, Pacific plate fixed)
- DeMets, C., R. G. Gordon, D. F. Argus, and S. Stein, Current plate motions, Geophys. J. Int., 101, 425-478, 1990.
- NUVEL-1A:(relative motion, Pacific plate fixed)
- DeMets. C., R. G. Gordon, D. F. Argus, and S. Stein, Effect of recent revisions to the geomagnetic reversal time scale on estimate of current plate motions, Geophys. Res. Lett., vol. 21, no. 20, 2191-2194, 1994.
- NNR-NUVEL-1:(absolute plate motion, no-net rotation)
- Argus D.F., R.G. Gordon, No-net-rotation model of current plate velocities incorporating plate motion model NUVEL-1. Geophys. Res. Lett. (18) 2039-2042, 1991.
- NNR-NUVEL-1A:(absolute plate motion, no-net rotation)
- DeMets. C., R. G. Gordon, D. F. Argus, and S. Stein, Effect of recent revisions to the geomagnetic reversal time scale on estimate of current plate motions, Geophys. Res. Lett., vol. 21, no. 20, 2191-2194, 1994.
- HS3-NUVEL-1A:(absolute plate motion, relative to hotspot frame)
- Gripp, A.E., and Gordon, R.G., Young tracks of hotspots and current plate velocities, Geophys. J. Int., 150, 321-361, 2002.
Please note that the velocity calculated based on NUVEL-1 and NUVEL-1A may be 4.5% and <2% faster than those measured by space geodetic methods by using VLBI/SLR.
- Gordon, R. G., Orbital dates and steady rates, Nature, 364, 760-761, 1993.
Used Equation:
- rotation vector
- MƒÖF= MƒÖP - FƒÖP = (ƒÖx, ƒÖy, ƒÖz)
- rotation pole
- plat = atan(ƒÖz / sqrt (ƒÖx*ƒÖx+ƒÖy*ƒÖy))
- plon = atan(ƒÖy/ƒÖx)
- rotation rate
- rate = sqrt(ƒÖx*ƒÖx+ƒÖy*ƒÖy*+ƒÖz*ƒÖz)
- velocity at a point (tlat,tlon)
- Vew = radius * cos (tlat)*rate*(sin(plat)-cos(plat)*tan(tlat)*cos(plon-tlon))
- Vns = radius * rate * cos(plat)*sin(tlon-plon)
- Velocity = sqrt (Vew*Vew + Vns*Vns)
- Direction = atan(Vew/Vns)
Last revised : November 11 2010 S bug report to okino@aori.u-tokyo.ac.jp