FIGURE 4. Correlation of spreading rate and incidence of hydrothermal plumes.
From the following article:
Magmatic and amagmatic seafloor generation at the ultraslow-spreading Gakkel ridge, Arctic Ocean
P. J. Michael, C. H. Langmuir, H. J. B. Dick, J. E. Snow, S. L. Goldstein, D. W. Graham, K. Lehnert, G. Kurras, W. Jokat, R. Mühe and H. N. Edmonds
Nature 423, 956-961(26 June 2003)
doi:10.1038/nature01704
Adapted from ref. 13 and including the Gakkel ridge estimate, which was calculated as the percentage of deployments of the MAPR for which an anomaly was recorded45. The plume incidence for Gakkel ridge is much higher than predicted by extrapolation from faster ridges, as a result of both vent frequency and hydrographic conditions (see text). SEIR., southeast Indian ridge
