Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Counter-rotating microplates at the Galapagos triple junction


An ‘incipient’ spreading centre east of (and orthogonal to) the East Pacific Rise at 2° 40′ N has been identified as forming a portion of the northern boundary of the Galapagos microplate1,2. This spreading centre was described as a slowly diverging, westward propagating rift, tapering towards the East Pacific Rise. Here we present evidence that the ‘incipient rift’ has also rifted towards the east and opens anticlockwise about a pivot at its eastern end. The ‘incipient rift’ then bounds a second microplate, north of the clockwise-rotating Galapagos microplate. The Galapagos triple junction region, in the eastern equatorial Pacific Ocean, thus consists of two counter-rotating microplates partly separated by the Hess Deep rift. Our kinematic solution for microplate motion relative to the major plates indicates that the two counter-rotating microplates may be treated as rigid blocks driven by drag on the microplates' edges3.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Bathymetric and magnetic data collected in the vicinity of the IR.
Figure 2: SeaBeam amplitude (side-scan) results and photographic images of the IR.
Figure 3: Tectonic configuration of the Galapagos triple junction and kinematic solution of the instantaneous motion of a dual microplate system.

Similar content being viewed by others


  1. Lonsdale, P. Structural pattern of the Galapagos microplate and evolution of the Galapagos triple junction. J. Geophys. Res. 93, 13551–13574 (1988)

    Article  ADS  Google Scholar 

  2. Lonsdale, P., Blum, N. & Puchelt, H. The RRR triple junction at the southern end of the Pacific-Cocos East Pacific Rise. Earth Planet. Sci. Lett. 109, 73–85 (1992)

    Article  ADS  CAS  Google Scholar 

  3. Schouten, H., Klitgord, K. D. & Gallo, D. G. Edge-driven microplate kinematics. J. Geophys. Res. 98, 6689–6701 (1993)

    Article  ADS  Google Scholar 

  4. Raff, A. D. Seafloor spreading: another rift. J. Geophys. Res. 73, 3699–3705 (1968)

    Article  ADS  Google Scholar 

  5. Hey, R. Tectonic evolution of the Cocos-Nazca spreading center. Geol. Soc. Am. Bull. 88, 1404–1420 (1977)

    Article  ADS  Google Scholar 

  6. Lonsdale, P. Regional shape and tectonics of the equatorial East Pacific Rise. Mar. Geophys. Res. 3, 295–315 (1977)

    Article  Google Scholar 

  7. Lonsdale, P. Linear volcanoes along the Pacific-Cocos plate boundary, 9°N to the Galapagos triple junction. Tectonophysics 116, 255–279 (1985)

    Article  ADS  Google Scholar 

  8. Searle, R. C. & Francheteau, J. Morphology and tectonics of the Galapagos triple junction. Mar. Geophys. Res. 8, 95–129 (1986)

    Google Scholar 

  9. Baker, E. T. & Milburn, H. B. MAPR: A new instrument for hydrothermal plume mapping. Ridge Events 8, 23–25 (1997)

    Google Scholar 

  10. Hanna, H. D., Klein, E. M., Smith, D. K. & Zhu, W. The Melville Vancouver Leg 01 Scientific Party. Along-axis geochemical variations in basaltic glasses from the Incipient Rift adjacent to the East Pacific Rise at 2°40′N. Eos 84, 1495 (2003)

    Google Scholar 

  11. Sims, K. W. W. et al. Aberrant youth: chemical and isotopic constraints on the origin of off-axis lavas from the East Pacific Rise, 9°-10°N. Geochem. Geophys. Geosyst. 4, doi:10.1029/2002GC000443 (2002)

  12. Parker, R. L. & Huestis, S. P. The inversion of magnetic anomalies in the presence of topography. J. Geophys. Res. 79, 1587–1594 (1974)

    Article  ADS  Google Scholar 

  13. Macdonald, K. C., Miller, S. P., Huestis, S. P. & Spiess, F. N. Three-dimensional modeling of a magnetic reversal boundary from inversion of deep-tow measurements. J. Geophys. Res. 85, 3670–3680 (1980)

    Article  ADS  Google Scholar 

  14. Gee, J. & Kent, D. V. Magnetization of axial lavas from the southern East Pacific Rise (14°-23°S): Geochemical controls on magnetic properties. J. Geophys. Res. 102, 24873–24886 (1997)

    Article  ADS  CAS  Google Scholar 

  15. Gee, J. S., Cande, S. C., Hildebrand, J. A., Donnelly, K. & Parker, R. L. Geomagnetic intensity variations over the past 780 kyr obtained from near-seafloor magnetic anomalies. Nature 408, 827–832 (2000)

    Article  ADS  CAS  Google Scholar 

  16. Carey, S. W. Continental Drift, a Symposium 177–355 (Geology Department, University of Tasmania, Hobart, 1958)

    Google Scholar 

  17. Naar, D. F. & Hey, R. N. Tectonic evolution of the Easter microplate. J. Geophys. Res. 96, 7961–7993 (1991)

    Article  ADS  Google Scholar 

  18. Larson, R. L. et al. Roller-bearing tectonic evolution of the Juan Fernandez microplate. Nature 356, 571–576 (1992)

    Article  ADS  Google Scholar 

  19. DeMets, C., Gordon, R. G., Argus, D. F. & Stein, S. Effect of recent revisions to the geomagnetic reversal timescale on estimates of current plate motions. Geophys. Res. Lett. 21, 2191–2194 (1994)

    Article  ADS  Google Scholar 

  20. Mitchell, N. C. Distributed extension at the Indian Ocean triple junction. J. Geophys. Res. 96, 8019–8043 (1991)

    Article  ADS  Google Scholar 

  21. Karson, J. A. et al. Structure of uppermost fast-spread oceanic crust exposed at the Hess Deep Rift: Implications for subaxial processes at the East Pacific Rise. Geochem. Geophys. Geosyst. 3, doi:10.1029/2001GC000155 (2002)

  22. Guyodo, Y. & Valet, J.-P. Global changes in intensity of the Earth's magnetic field during the past 800 kyr. Nature 399, 249–252 (1999)

    Article  ADS  CAS  Google Scholar 

Download references


We are grateful to the captain and crew of the R/V Melville (Vancouver Leg 01). The Incipient Rift Team included E. Klein, D. Smith, R. Cheney, R. Comer, C. Donnelly, P. Gregg, H. Hanna, G. Kurras, J. McGuire, M. Pollock, M. Rudnicki, E. Williams, C. Williams and W. Zhu. We thank G. Christeson for collecting additional bathymetry and magnetic data for us, and R. Searle and D. Wilson for comments that improved the manuscript. This work was supported by the US National Science Foundation.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Emily M. Klein.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Information and Supplementary Table 1. (DOC 27 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Klein, E., Smith, D., Williams, C. et al. Counter-rotating microplates at the Galapagos triple junction. Nature 433, 855–858 (2005).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing