Wishbone scarp

Wishbone scarp
West Wishbone scarp, Western Wishbone Ridge, East Wishbone scarp, Eastern Wishbone Ridge, Wishbone–East Manihiki scarp
Map
Map of Wishbone scarp (black) to show position relative to nearby land
Coordinates31°22′S 164°49′W / 31.36°S 164.81°W / -31.36; -164.81 (extends at least from 29°28'S to 41°32'S)[1]
Characteristics
Top depth2,930 metres (9,613 ft)[2]
Part ofOceanic Pacific Plate
LengthOver 1,400 km (870 mi)[1]
Tectonics
PlatePacific Plate
EarthquakesInactive
Age116–71 Ma
Wishbone
scarp
West
Wishbone 
scarp  
East
Wish-
bone
scarp
West
Wishbone 
scarp    
The scarps associated with the Wishbone Scarp are labelled on this ocean floor map that shows features relevant to the eastern margins (black outline) of the subcontinent of Zealandia. The diagonal chain of the Louisville seamounts crosses the western scarp at almost right angles. The violet line is the very deep trenches of the Kermadec-Tonga subduction zone with its arc volcanoes to the top left. Blue represents ocean depths of a kilometer or so and brown shades are shallower.

The Wishbone scarp is a Pacific Ocean floor feature in the oceanic crust, that if it were on land would be similar to a mountain range fault system over 1,000 km (620 mi) long. It commences in the north near the Osbourn Trough although it is likely to be related tectonically to the Manihiki scarp somewhat to its north. To the south it splits into west and east scarps that have been intercepted by the Louisville hotspot with the West Wishbone scarp continuing until it intercepts the Chatham Rise. There is now evidence that the entire scarp has a fracture zone origin resolving previous uncertainty on this issue.

To the east of the eastern scarp are the very deep Pacific mid ocean basins, while to the west of the western scarp we have the shallower but currently very tectonically active Hikurangi Margin.

  1. ^ a b Cite error: The named reference Fig1 was invoked but never defined (see the help page).
  2. ^ Mortimer et al. 2006, p185