Tectonic plate boundary in the South Pacific Ocean
Approximate surface projection on Pacific Ocean of Pacific-Antarctic Ridge (purple). Features associated with fracture zones (orange) are also shown (lighter orange). Click to expand map to obtain interactive fracture zone details.[1]
The divergence rate between the two plates along the ridge is believed to vary from about 5.4 centimetres per year (2.1 in/year) near
65°S to 7.4 centimetres per year (2.9 in/year) near the Udintsev Fracture Zone at 55°S.[4]: 1281
The ridge is related to the Late Cretaceous breakup of Gondwana. To the southeast the historic Bellingshausen Plate separated the Pacific and Antarctic plates between about 84 to 61 million years ago.[5]: Fig 9. Until about 33 million years ago, the Proto-Antipodes Fracture Zone well to the south separated two independent spreading centers, now merged, being the Antarctic–Pacific Ridge and that of the Antarctic–Campbell Plateau.[5]: 14
^General citations for named fracture zones are at page Wikipedia:Map data/Fracture zone and specific citations are in interactive detail.
^Geli, L; Bougault, H; Aslanian, D; Briais, A; Dosso, L; Etoubleau, J; Le Formal, JP; Maia, M; Ondreas, H; Olivet, JL; Richardson, C (1997). "Evolution of the Pacific-Antarctic Ridge South of the Udintsev Fracture Zone". Science. 278 (5341): 1281–1284. doi:10.1126/science.278.5341.1281.