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.

  • Article
  • Published:

Mid-ocean ridge unfaulting revealed by magmatic intrusions


Mid-ocean ridges (MORs) are quintessential sites of tectonic extension1,2,3,4, at which divergence between lithospheric plates shapes abyssal hills that cover about two-thirds of the Earth’s surface5,6. Here we show that tectonic extension at the ridge axis can be partially undone by tectonic shortening across the ridge flanks. This process is evidenced by recent sequences of reverse-faulting earthquakes about 15 km off-axis at the Mid-Atlantic Ridge and Carlsberg Ridge. Using mechanical models, we show that shallow compression of the ridge flanks up to the brittle failure point is a natural consequence of lithosphere unbending away from the axial relief. Intrusion of magma-filled fractures, which manifests as migrating swarms of extensional seismicity along the ridge axis, can provide the small increment of compressive stress that triggers reverse-faulting earthquakes. Through bathymetric analyses, we further find that reverse reactivation of MOR normal faults is a widely occurring process that can reduce the amplitude of abyssal hills by as much as 50%, shortly after they form at the ridge axis. This ‘unfaulting’ mechanism exerts a first-order influence on the fabric of the global ocean floor and provides a physical explanation for reverse-faulting earthquakes in an extensional environment.

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

Fig. 1: Swarms of normal and reverse seismicity at two slow-spreading MORs.
Fig. 2: Tectonic strain and the bathymetric signature of unfaulting.
Fig. 3: The stress state of MOR shoulders.
Fig. 4: MOR unfaulting.

Similar content being viewed by others

Data availability

All bathymetric data used in this study are from the published literature as referenced 50,67,68 or openly available in the GMRT ( and NOAA-NCEI ( repositories. The fault scarp dataset in ref. 24 is provided in Supplementary Table 4. Earthquake data are from the Global CMT catalogue (, except for earthquake relocations, which are provided in Supplementary Table 1.

Code availability

The simulation shown in Fig. 3a was run with the version of the FLAC code60 developed in refs. 30,31. This code and the corresponding visualization scripts are available from the corresponding author on reasonable request. The stress calculations shown in Fig. 3a were carried out with the code openly distributed with ref. 64.


  1. Sykes, L. R. Mechanism of earthquakes and nature of faulting on the mid-oceanic ridges. J. Geophys. Res. 72, 2131–2153 (1967).

    Article  ADS  Google Scholar 

  2. Engeln, J. F., Wiens, D. A. & Stein, S. Mechanisms and depths of Atlantic transform earthquakes. J. Geophys. Res. 91, 548–577 (1986).

    Article  ADS  Google Scholar 

  3. Huang, P. Y., Solomon, S. C., Bergman, E. A. & Nabelek, J. L. Focal depths and mechanism of Mid-Atlantic Ridge earthquakes from body waveform inversion. J. Geophys. Res. 91, 579–598 (1986).

    Article  ADS  Google Scholar 

  4. Solomon, S. C., Huang, P. Y. & Meinke, L. The seismic moment budget of slowly spreading ridges. Nature 334, 58–60 (1988).

    Article  ADS  Google Scholar 

  5. Menard, H. W. & Mammerickx, J. Abyssal hills, magnetic anomalies and the East Pacific Rise. Earth Planet. Sci. Lett. 2, 465–472 (1967).

    Article  ADS  Google Scholar 

  6. Macdonald, K. C., Fox, P. J., Alexander, R. T., Pockalny, R. & Gente, P. Volcanic growth faults and the origin of Pacific abyssal hills. Nature 380, 125–129 (1996).

    Article  ADS  CAS  Google Scholar 

  7. Olive, J.-A. et al. Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply. Science 350, 310–313 (2015).

    Article  ADS  CAS  PubMed  Google Scholar 

  8. Deffeyes, K. S. in Megatectonics of Continents and Oceans (eds Johnson, J. & Smith, B. L.) 194–222 (Rutgers Univ. Press, 1970).

  9. Osmaston, M. F. Genesis of ocean ridge median valleys and continental rift valleys. Tectonophysics 11, 387–405 (1971).

    Article  ADS  Google Scholar 

  10. Harrison, C. G. A. Tectonics of mid-ocean ridges. Tectonophysics 22, 301–310 (1974).

    Article  ADS  Google Scholar 

  11. Macdonald, K. C. Mid-ocean ridges: fine scale tectonic, volcanic and hydrothermal processes within the plate boundary zone. Annu. Rev. Earth Planet. Sci. 10, 155–190 (1982).

    Article  ADS  Google Scholar 

  12. Needham, H. D. & Francheteau, J. Some characteristics of the Rift Valley in the Atlantic Ocean near 36° 48′ north. Earth Planet. Sci. Lett. 22, 29–43 (1974).

    Article  ADS  Google Scholar 

  13. Bergman, E. A. & Solomon, S. C. Source mechanisms of earthquakes near mid-ocean ridges from body waveform inversion: implications for the early evolution of oceanic lithosphere. J. Geophys. Res. 89, 11415–11441 (1984).

    Article  ADS  Google Scholar 

  14. Fleitout, L. & Froidevaux, C. Tectonic stresses in the lithosphere. Tectonics 2, 315–324 (1983).

    Article  ADS  Google Scholar 

  15. Wolfe, C. J., Bergman, E. A. & Solomon, S. C. Oceanic transform earthquakes with unusual mechanisms or locations: relation to fault geometry and state of stress in the adjacent lithosphere. J. Geophys. Res. 98, 16187–16211 (1993).

    Article  ADS  Google Scholar 

  16. Turcotte, D. L. Are transform faults thermal contraction cracks? J. Geophys. Res. 79, 2573–2577 (1974).

    Article  ADS  Google Scholar 

  17. Behn, M. D., Lin, J. & Zuber, M. T. Evidence for weak oceanic transform faults. Geophys. Res. Lett. 29, 2207 (2002).

    Article  ADS  Google Scholar 

  18. Janin, A. et al. Tectonic evolution of a sedimented oceanic transform fault: the Owen Transform Fault, Indian Ocean. Tectonics 42, e2023TC007747 (2023).

    Article  ADS  Google Scholar 

  19. Cesca, S., Metz, M., Büyükakpınar, P. & Dahm, T. The energetic 2022 seismic unrest related to magma intrusion at the North Mid-Atlantic Ridge. Geophys. Res. Lett. 50, e2023GL102782 (2023).

    Article  ADS  Google Scholar 

  20. Jackson, J. & McKenzie, D. Reverse-faulting earthquakes and the tectonics of slowly-spreading mid-ocean ridge axes. Earth Planet. Sci. Lett. 618, 118279 (2023).

    Article  CAS  Google Scholar 

  21. Escartín, J. et al. Central role of detachment faults in accretion of slow-spreading oceanic lithosphere. Nature 455, 790–794 (2008).

    Article  ADS  PubMed  Google Scholar 

  22. Searle, R. C. & Laughton, A. S. Sonar studies of the Mid-Atlantic Ridge and Kurchatov Fracture Zone. J. Geophys. Res. 82, 5313–5328 (1977).

    Article  ADS  Google Scholar 

  23. Escartín, J. et al. Quantifying tectonic strain and magmatic accretion at a slow spreading ridge segment, Mid-Atlantic Ridge, 29°N. J. Geophys. Res. 104, 10421–10437 (1999).

    Article  ADS  Google Scholar 

  24. Howell, S. et al. Magmatic and tectonic extension at the Chile Ridge: evidence for mantle controls on ridge segmentation. Geochem. Geophys. Geosyst. 17, 2354–2373 (2016).

    Article  ADS  CAS  Google Scholar 

  25. Qin, R. & Buck, W. R. Why meter-wide dikes at spreading centers? Earth Planet. Sci. Lett. 265, 466–474 (2008).

    Article  ADS  CAS  Google Scholar 

  26. Olive, J.-A. & Dublanchet, P. Controls on the magmatic fraction of extension at mid-ocean ridges. Earth Planet. Sci. Lett. 549, 116541 (2020).

    Article  CAS  Google Scholar 

  27. Buck, W. R., Lavier, L. L. & Poliakov, A. N. B. Modes of faulting at mid-ocean ridges. Nature 434, 719–723 (2005).

    Article  ADS  CAS  PubMed  Google Scholar 

  28. Behn, M. D. & Ito, G. Magmatic and tectonic extension at mid-ocean ridges: 1. Controls on fault characteristics. Geochem. Geophys. Geosyst. 9, Q08O10 (2008).

    Article  Google Scholar 

  29. Tucholke, B. E. et al. Role of melt supply in oceanic detachment faulting and formation of megamullions. Geology 36, 455–458 (2008).

    Article  ADS  Google Scholar 

  30. Liu, Z. & Buck, W. R. Global trends of axial relief and faulting at plate spreading centers imply discrete magmatic events. J. Geophys. Res. 125, e2020JB019465 (2020).

    Article  ADS  Google Scholar 

  31. Liu, Z. & Buck, W. R. Magmatic controls on axial relief and faulting at mid-ocean ridges. Earth Planet. Sci. Lett. 491, 226–237 (2018).

    Article  ADS  CAS  Google Scholar 

  32. Qin, R. & Buck, W. R. Effect of lithospheric geometry on rift valley relief. J. Geophys. Res. 110, B03404 (2005).

    Article  ADS  Google Scholar 

  33. Turcotte, D. L. & Schubert, G. Geodynamics 2nd edn (Cambridge Univ. Press, 2002).

  34. Buck, W. R. Accretional curvature of lithosphere at magmatic spreading centers and the flexural support of axial highs. J. Geophys. Res. 106, 3953–3960 (2001).

    Article  ADS  Google Scholar 

  35. Ekström, G., Nettles, M. & Dziewonski, A. M. The global CMT project 2004–2010: centroid-moment tensors for 13,017 earthquakes. Phys. Earth Planet. Inter. 200–201, 1–9 (2012).

    Article  ADS  Google Scholar 

  36. Parnell-Turner, R. et al. Oceanic detachment faults generate compression in extension. Geology 45, 923–926 (2017).

    Article  ADS  Google Scholar 

  37. Mitchell, N. C., Allerton, S. & Escartín, J. Sedimentation on young ocean floor at the Mid-Atlantic Ridge, 29 °N. Mar. Geol. 148, 1–8 (1998).

    Article  ADS  Google Scholar 

  38. Ewing, J. & Ewing, M. Sediment distribution on the mid-ocean ridges with respect to spreading of the sea floor. Science 156, 1590–1592 (1967).

    Article  ADS  CAS  PubMed  Google Scholar 

  39. Divins, D. L. Total sediment thickness of the world’s oceans & marginal seas. NOAA National Geophysical Data Center (2003).

  40. Johnson, H. P. & Pruis, M. J. Fluid and heat from the oceanic crustal reservoir. Earth Planet. Sci. Lett. 216, 565–574 (2003).

    Article  ADS  CAS  Google Scholar 

  41. Tucholke, B. W., Stewart, K. W. & Kleinrock, M. C. Long-term denudation of ocean crust in the central North Atlantic Ocean. Geology 25, 171–174 (1997).

    Article  ADS  Google Scholar 

  42. Cannat, M., Mangeney, A., Ondréas, H., Fouquet, Y. & Normand, A. High-resolution bathymetry reveals contrasting landslide activity shaping the walls of the Mid-Atlantic Ridge axial valley. Geochem. Geophys. Geosyst. 14, 996–1011 (2013).

    Article  ADS  Google Scholar 

  43. Olive, J.-A. & Escartín, J. Dependence of seismic coupling on normal fault style along the Northern Mid-Atlantic Ridge. Geochem. Geophys. Geosyst. 17, 4128–4152 (2016).

    Article  ADS  Google Scholar 

  44. Liu, Y. & Ric, J. R. Spontaneous and triggered aseismic deformation transients in a subduction fault model. J. Geophys. Res. 112, B09404 (2007).

    Article  ADS  Google Scholar 

  45. Mark, H. F., Behn, M. D., Olive, J.-A. & Liu, Y. Controls on mid-ocean ridge normal fault seismicity across spreading rates from rate-and-state friction models. J. Geophys. Res 123, 6719–6733 (2018).

    Article  ADS  Google Scholar 

  46. Einarsson, P. & Brandsdóttir, B. Seismological evidence for lateral magma intrusion during the July 1978 deflation of the Krafla volcano in NE-Iceland. J. Geophys. Res. 47, 160–165 (1980).

    Google Scholar 

  47. Keir, D. et al. Evidence for focused magmatic accretion at segment centers from lateral dike injections captured beneath the Red Sea rift in Afar. Geology 37, 59–62 (2009).

    Article  ADS  Google Scholar 

  48. Bohnenstiehl, D. R., Dziak, R. P., Tolstoy, M., Fox, C. & Fowler, M. Temporal and spatial history of the 1999–2000 Endeavour Segment seismic series, Juan de Fuca Ridge. Geochem. Geophys. Geosyst. 5, Q09003 (2004).

    Article  ADS  Google Scholar 

  49. Tolstoy, M., Bohnenstiehl, D. R., Edwards, M. & Kurras, G. Seismic character of volcanic activity at the ultraslow-spreading Gakkel Ridge. Geology 29, 1139–1142 (2001).

    Article  ADS  Google Scholar 

  50. Skolotnev, S. G. et al. Crustal accretion along the northern Mid Atlantic Ridge (52°–57°N): preliminary results from expedition V53 of R/V Akademik Sergey Vavilov. Ofioliti 48, 13–30 (2023).

    Google Scholar 

  51. Ekström, G. Global detection and location of seismic sources by using surface waves. Bull. Seismol. Soc. Am. 96, 1201–1212 (2006).

    Article  Google Scholar 

  52. Smith, G. P. & Ekström, G. Interpretation of earthquake epicenter and CMT centroid locations, in terms of rupture length and direction. Phys. Earth Planet. Inter. 102, 123–132 (1997).

    Article  ADS  Google Scholar 

  53. Howe, M., Ekström, G. & Nettles, M. Improving relative earthquake locations using surface-wave source corrections. Geophys. J. Int. 219, 297–312 (2019).

    Article  ADS  Google Scholar 

  54. Dziewonski, A. M., Chou, T.-A. & Woodhouse, J. H. Determination of earthquake source parameters from waveform data for studies of global and regional seismicity. J. Geophys. Res. 86, 2825–2852 (1981).

    Article  ADS  Google Scholar 

  55. Ekström, G. & Dziewonski, A. M. Centroid-moment tensor solutions for 35 earthquakes in Western North America (1977-1983). Bull. Seismol. Soc. Am. 75, 23–39 (1985).

    Article  Google Scholar 

  56. Ekström, G. A very broad band inversion method for the recovery of earthquake source parameters. Tectonophysics 166, 73–100 (1989).

    Article  ADS  Google Scholar 

  57. Escartín, J. & Olive, J.-A. in Treatise on Geomorphology 2nd edn 847–881 (Elsevier, 2022).

  58. Hughes, A. et al. Quantification of gravitational mass wasting and controls on submarine scarp morphology along the Roseau fault, Lesser Antilles. J. Geophys. Res. Earth Surface 126, e2020JF005892 (2021).

    Article  ADS  Google Scholar 

  59. Olive, J.-A. & Behn, M. D. Rapid rotation of normal faults due to flexural stresses: an explanation for the global distribution of normal fault dips. J. Geophys. Res. 119, 3722–3739 (2014).

    Article  ADS  Google Scholar 

  60. Cundall, P. A. Numerical experiments on localization in frictional materials. Ing. Arch. 59, 148–159 (1989).

    Article  Google Scholar 

  61. Poliakov, A. N. B., Podladchikov, Y. & Talbot, C. Initiation of salt diapirs with frictional overburdens: numerical experiments. Tectonophysics 228, 199–210 (1993).

    Article  ADS  Google Scholar 

  62. Lavier, L. L., Buck, W. R. & Poliakov, A. N. B. Factors controlling normal fault offset in an ideal brittle layer. J. Geophys. Res. 105, 23431–23442 (2000).

    Article  ADS  Google Scholar 

  63. Mackwell, S. J., Zimmerman, M. E. & Kohlstedt, D. L. High‐temperature deformation of dry diabase with application to tectonics on Venus. J. Geophys. Res. 103, 975–984 (1998).

    Article  ADS  Google Scholar 

  64. Meade, B. J. Algorithms for the calculation of exact displacements, strains, and stresses for triangular dislocation elements in a uniform elastic half space. Comput. Geosci. 33, 1064–1075 (2007).

    Article  ADS  Google Scholar 

  65. Heap, M. J. et al. Towards more realistic values of elastic moduli for volcano modelling. J. Volcanol. Geotherm. Res. 390, 106684 (2020).

    Article  CAS  Google Scholar 

  66. King, G. C. P., Stein, R. S. & Lin, J. Static stress changes and the triggering of earthquakes. Bull. Seismol. Soc. Am. 84, 935–953 (1994).

    Google Scholar 

  67. Maia, M. COLMEIA cruise. RV L’Atalante. (2013).

  68. Maia, M. et al. Extreme mantle uplift and exhumation along a transpressive transform fault. Nat. Geosci. 9, 619–623 (2016).

    Article  ADS  CAS  Google Scholar 

Download references


G.E. received support from the Consortium for Monitoring, Technology, and Verification under the Department of Energy National Nuclear Security Administration award number DE-NA0003920. Z.L. was supported by the JLU Science and Technology Innovative Research Team programme (no. 2021TD-05). M.B. was supported by the ISblue project (Interdisciplinary Graduate School for the Blue Planet: ANR-17-EURE-0015) co-funded by a France 2030/Investissement d’Avenir grant from the French government. We thank our editor and the reviewers for their insightful feedback. We also thank I. Grevemeyer, S. Cesca, S. Solomon and A. Janin for helpful discussions. J. Chen and L. C. Malatesta provided valuable assistance with figure design. Finally, we thank S. Skolotnev and M. Ligi for providing the Mid-Atlantic Ridge 54° N bathymetric data.

Author information

Authors and Affiliations



J.-A.O. designed the study, conducted the bathymetric analyses with J.E. and M.B., carried out the elastic stress modelling and wrote the initial manuscript. G.E. compiled and analysed the earthquake data. W.R.B. and Z.L. designed the models of ridge flank flexure. All authors discussed and analysed the results and provided feedback on the manuscript.

Corresponding author

Correspondence to Jean-Arthur Olive.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature thanks Delwayne Bohnenstiehl, Ingo Grevemeyer and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Examples of near-axis compression at MORs.

a, Bathymetric map of the Southeast Indian Ridge (SEIR) near 115° E, with focal mechanisms from the CMT catalogue. b, Bathymetric map of the Mid-Atlantic Ridge (MAR) south of the Marathon transform fault (TF), with focal mechanisms from the CMT catalogue. c, Bathymetric profile across the SEIR (dashed line in panel a), with coloured segments indicating fault scarps. d, Cumulative fault heave versus distance from the axis for the southern (red) and northern (yellow) sides of the SEIR, with best-fitting piecewise linear functions shown as dashed lines (T = 0.13, T′ = 0.05 on the south side; T = 0.09, T′ = 0.07 on the north side). e, Bathymetric profile across the western flank of the MAR (dashed line in panel b), with coloured segments indicating fault scarps. f, Cumulative fault heave versus distance from the axis for the western side of the MAR, with best-fitting piecewise linear function shown as dashed lines (T = 0.21, T′ = 0.08).

Extended Data Fig. 2 The 2022 northern Mid-Atlantic Ridge and 2014 Carlsberg Ridge seismic sequences.

Latitude and moment magnitude of earthquakes, colour-coded by mechanism (blue, reverse faulting; red, normal faulting) and location, throughout the 2022 Mid-Atlantic Ridge sequence (ad) and 2014 Carlsberg Ridge sequence (eh).

Extended Data Fig. 3 Examples of near-axis reverse-faulting earthquakes at MORs.

Bathymetric maps, reverse focal mechanism and profile used for strain analyses at the Mid-Atlantic Ridge 0° 50′ N near the St. Paul transform fault (TF)67,68 (a); Mid-Atlantic Ridge 7° 50′ S (b); Mid-Atlantic Ridge 34° 50′ N (c); Carlsberg Ridge 9° 45′ N (d); Mid-Atlantic Ridge 1° 20′ S (e); Southwest Indian Ridge 18° 30′ E (f); Mid-Atlantic Ridge 17° S (g); Southwest Indian Ridge 43° E near the Discovery II transform fault (TF) (h); and Southwest Indian Ridge 57° E (i). FZ, fracture zone.

Extended Data Fig. 4 Bathymetric signatures of unfaulting in the Atlantic Ocean.

Left, bathymetric cross-sections with fault scarps highlighted in colour. Right, plots of cumulative fault heave versus distance at selected sections of the Mid-Atlantic Ridge. Corresponding values of T, T′ and xc are listed in Supplementary Table 3.

Extended Data Fig. 5 Bathymetric signatures of unfaulting in the Indian Ocean.

Left, bathymetric cross-sections with fault scarps highlighted in colour. Right, plots of cumulative fault heave versus distance at selected sections of the Southwest Indian Ridge and the Carlsberg Ridge. Corresponding values of T, T′ and xc are listed in Supplementary Table 3.

Extended Data Fig. 6 Unfaulting along the intermediate-spreading Chile Ridge.

a, Bathymetric map of the Chile Ridge axis outlining its main segments, adapted from ref. 24. Insets detail bathymetry of segments N1 and N9N–N9S. Position (b) and amplitude (c) of the change in apparent T at the Chile Ridge: histograms of xc and (T − T′) for all transects across the Chile Ridge, excluding poor fits highlighted in grey in Supplementary Table 3. d, Average slope of axis-facing scarps versus distance to the ridge axis. Data are from the fault scarp compilation of ref. 24.

Extended Data Fig. 7 Tectonically accommodated strain along the Chile Ridge.

Cumulative fault heave versus distance from the axis along individual transects from each segment of the Chile Ridge, based on the fault scarp compilation of ref. 24. Red and yellow dots correspond to the western and eastern sides of the axis, respectively, with best-fitting piecewise linear functions shown as black lines. This excludes poor fits highlighted in grey in Supplementary Table 3.

Extended Data Fig. 8 Amplitude and position of the change in apparent T along the Chile Ridge.

ai, Histograms of the amplitude of the change (T − T′) in apparent T in each bathymetric transect, grouped by segment. jr, Histograms of the distance xc for which the change in apparent T occurs in each bathymetric transect. These plots exclude poor fits highlighted in grey in Supplementary Table 3.

Extended Data Fig. 9 Lack of unfaulting near an axial high.

a, Bathymetric map of the fast-spreading East Pacific Rise at 9° 30′ N, which—unlike every other ridge section studied here—features an axial high instead of an axial valley. White line indicates the location of the bathymetric transect. b, Bathymetric cross-sections with fault scarps highlighted in colour. c, Cumulative fault heave versus distance, with best-fitting piecewise linear function shown as black lines. In this case, T′ > T.

Extended Data Fig. 10 Mechanics of ridge shoulder unbending.

The yield stress of the lithosphere σy is defined as the difference between the vertical and horizontal stresses needed to produce fault slip. a, An idealized plate that was accreted with curvature and no bending stresses. σ0 is an assumed background stress difference. The simple case shown has no cohesion and parameters A and B depend strongly on the friction coefficient f and assumed pore pressure PP on the faults, as defined in the Supplementary Information. b, A case with reverse faults that are three times stronger than normal faults. c, Deepening of the neutral depth, D, when the reverse faults are assumed to be weaker than the normal faults. d, Analytical estimate of the neutral depth D, which marks the base of the compressive zone in an unbending ridge shoulder. The ratio of D to the layer thickness, H, is plotted versus the ratio of pore pressures on reverse versus normal faults assuming f = 0.75 and that the pore pressure on normal faults is one-third the lithostatic pressure (blue curve). Assuming a rock density of 3,000 kg m−3 and water density of 1,000 kg m−3, the left limit is for hydrostatic pore pressure on the reverse faults, whereas the right limit is for lithostatic pore pressure on the reverse faults. Red curve shows the effect on the neutral depth of a regional horizontal extensional stress difference equal to 20% of the extensional yield stress at the base of the layer. See Supplementary Information for details.

Supplementary information

Supplementary Information

Supplementary Methods describing the fault scarp dataset from the Chile Ridge and detailing a simple analytical model for the depth of the compressive zone taking into account the effect of pore fluid pressure.

Supplementary Table 1

Relocated earthquakes at the Mid-Atlantic Ridge and the Carlsberg Ridge. Event code follows the convention of Global CMT catalogue. Table also includes depth estimates for four events from the 2022 Mid-Atlantic Ridge 53º N earthquake swarm.

Supplementary Table 2

Unfaulting earthquakes. List of reverse earthquakes from the Global CMT catalogue that occurred in areas mapped with high-resolution shipboard echosounders. Events labelled JM_X are part of the compilation from ref. 20.

Supplementary Table 3

Compilation of unfaulting signatures in high-resolution seafloor bathymetry. Best-fitting slope T of cumulative fault offset versus distance to the ridge axis near the axis (T best, with maximum and minimum estimates) and away from the axis (T′), past critical distance xc. Each row is a bathymetric transect on a specified side of the ridge axis. Shaded rows are transects that did not yield a satisfactory fit with a piecewise linear function.

Supplementary Table 4

Normal faults along the Chile Ridge. Original dataset from ref. 24. Each fault is identified along a ridge-normal transect by the position of the bottom and top of its seafloor scarp (locations 1 and 2). Positive and negative distances to the ridge axis correspond to fault located west and east of the axis, respectively. Segments are numbered as follows (#1–#9): N1, N10, N5, N8, N9N, N9S, S5N, S5S and V4.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Olive, JA., Ekström, G., Buck, W.R. et al. Mid-ocean ridge unfaulting revealed by magmatic intrusions. Nature 628, 782–787 (2024).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


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