New Zealand: 3D mapping has revealed remarkable features of a sprawling submerged ridge east of Auckland. There wasn’t much information about the Colville Ridge, stretching more than 200km towards Fiji, until a recent research voyage enabled marine geologists to map it in detail for the first time. The insights, part of a project to create state-of-the-art maps of New Zealand's entire exclusive economic zone, could prompt a rethink about the origin of the vast ridge. Three-dimensional imaging shows a mountainous ridge covered with jagged cones and with valleys that lie about 2km below the top of its peaks.
"Essentially, what we have done is strip the ocean away and so people can see this part of the Earth's surface for the first time. It's amazing to think this area is only 200km east of Auckland and ships have been sailing over it for more than a century pretty much oblivious to what lay beneath. We set out to map what we thought was an ancient volcanic arc. We were surprised to find it wasn't dominated by volcanic rocks, but more a mixture of them with large tracts of sedimentary rocks,” said Chief scientist, Dr Cornel de Ronde, of GNS Science.
Source: NZ herald