New Hawaii-MR1 sonar data show that the southernmost Mid-Atlantic
Ridge joins the South American-Antarctic Ridge by an obliquely
opening rift and overlaps Spiess Ridge, the westernmost
segment of the Southwest Indian Ridge, with no evidence for
a transform fault. The junction is therefore neither ridge-ridge-ridge
nor fault-fault-fault. We speculate that growth of Spiess Ridge
adjacent to the triple junction has caused this complexity
and discuss more generally the origins of distributed deformation
at oceanic triple junctions.
Mitchell, N. C., and R. A. Livermore, The present configuration of the Bouvet triple junction,
Geology, 26, 267-270, 1998.