Because the oceanic lithosphere is formed at spreading centers, mid-ocean ridge seismicity directly reflects the evolution of the oceanic lithosphere. The mechanisms of these earthquakes show the basic kinematics of ridges and transforms. Moreover, this seismicity provides key evidence for the thermal-mechanical process that controls the evolution of the oceanic lithosphere.
Figure 1contrasts the distribution of earthquakes on a portion of the Mid-Atlantic Ridge and the East Pacific Rise. On the Mid-Atlantic Ridge both the north-south trending ridge crest segments and the east-west trending transforms are seismically active. New lithosphere is formed at the ridges by seafloor spreading and then moves away. At the ridge crest, an axial valley forms parallel to the ridge trend. Normal faulting earthquakes are found to occur in this region with nodal planes parallel to the ridge trend. The transform faults are the sites of relative motion between lithosphere moving in opposite...
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References
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© 1989 Van Nostrand Reinhold
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Stein, S., Woods, D.F. (1989). Seismicity: Mid-ocean ridge . In: Geophysics. Encyclopedia of Earth Science. Springer, Boston, MA. https://doi.org/10.1007/0-387-30752-4_128
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DOI: https://doi.org/10.1007/0-387-30752-4_128
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