Platform subsidence behind an active subduction zone

A study of the link between subduction initiation and platform subsidence in New Zealand revealed that flexural foredeep was not responsible for the observed 1500 meter subsidence due to a broad wavelength, which was greater than 200 kilometers. Viscous mantle flow models predict that platform subsidence, which occurs above subduction zones, may cause depression that are two kilometers deep and 500 to 1000 kilometers wide.