Purpose: This Web site helps users calculate the present relative or no-net-rotation velocities of selected tectonic plates with the MORVEL or NNR-MORVEL56 angular velocities. It also provides information and source data for MORVEL, NNR-MORVEL56, and their underlying data.
History: The MORVEL plate motion project began in the late 1990s via a National Science Foundation grant to professors Charles DeMets of the University of Wisconsin-Madison and Richard Gordon of Rice University. MORVEL is a set of angular velocities and uncertainties that describes the geologically recent motions of 25 tectonic plates that collectively cover 97.2% of Earth's surface. MORVEL is constructed from marine geophysical, seismologic, and geodetic data from archives and investigators in ten different countries and employs many more data than the NUVEL-1 and NUVEL-1A plate motion estimates, which were published in 1990 and 1994. Finished in 2008 after nearly a decade of intensive data analysis, MORVEL is the most complete, self-consistent estimate of geologic plate motions ever published.
NNR-MORVEL56 is a set of angular velocities that describe the motions of 56 plates relative to a no-net-rotation reference frame. Spearheaded by Dr. Donald Argus of the NASA Jet Propulsion Laboratory, NNR-MORVEL56 extends the 25-plate MORVEL model, which covers 97.2% of Earth's surface, to the remaining 2.8% of the surface by incorporating 31 additional small plates defined by Bird (2003). By design, NNR-MORVEL56 gives velocities identical to MORVEL for the 25 plates included in both models.
MORVEL and NNR-MORVEL56 are products of collaborative research between Professors DeMets and Gordon and Dr. Donald Argus of the NASA Jet Propulsion Laboratory. Further information and graphics, including calculators that help users determine current plate motions from MORVEL and NNR-MORVEL56, are found via the links in the left-hand column.
Structure: The Web site is navigated using the menu in the left-hand column. The underlying source code is a combination of CSS (cascading style sheets), PHP, XHTML, and Linux shell scripts. It requires a CSS-capable browser. Older versions of Internet Explorer and Netscape may not work with this Web site.
The citation for MORVEL is
DeMets, C., Gordon, R. G., and Argus, D. F., 2010. Geologically current plate motions, Geophysical Journal International, v. 181, no. 1, p. 1-80, doi: 10.1111/j.1365-246X.2009.04491.x
The citation for NNR-MORVEL56 is
Argus, D. F., Gordon, R. G., and DeMets, C., 2011. Geologically current motion of 56 plates relative to the no-net-rotation reference frame, Geochemistry, Geophysics, Geosystems, accepted for publication, September, 2011.
Click here for the abstract (PDF) of the MORVEL publication.
Click here for ERRATA for the MORVEL publication, most importantly a corrected version of the GPS-ITRF0X angular velocities in Table 4.
For the definitive published version of the MORVEL paper, go to www.blackwell-synergy.com (cookies required)
or contact Chuck DeMets (firstname.lastname@example.org).
Our thanks to the Royal Astronomical Society and Blackwell Publishing for their superb handling of the manuscript.
Click here for the supplementary documentation (PDF) that accompanies the above publication.