chapter to my colleague and good friend, Jean Francheteau, who died after a long
illness on July 21, 2010. Jean was the chief scientist who conducted the diving
expedition on the Easter microplate, including the work done on the Terevaka
transform fault.
The Terevaka transform fault, located at 24°13
0 S and 115°41
0 W, is a left-lateral
transform disrupting two segments of the western spreading ridges within the Easter
Microplate (Fig. 8.12a–c). A microplate is a small, rigid plate about 300–600 km in
diameter that is trapped between larger (thousands of square kilometers-sized)
plates. A microplate is formed during the motion of major plate reorganization. It is
characterized by two spreading ridge systems that propagate in opposite directions
within the microplate, and the microplate itself is bordered by transform faults and/
or fracture zones. For example, the Easter microplate is about 400 9 400 km and is
located between 22°40
0 S and 27°S in a region where the ridge system is spreading
at a high rate (total rate of 16 cm/yr) (Naar and Hey 1989; Francheteau et al. 1988;
Fig. 8.12 Terevaka transform fault and geological setting, south Pacific. a General map of the
East Pacific Rise (EPR). b The Easter Microplate (EM) and spreading ridge segments are shown.
c Bathymetry of the Terevaka transform and the location of the submersible dives (dark lines) are
shown
Terevaka Transform Fault
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