Climate-controlled mountain building: Tectonic consequences of the rain shadow in the Southern Alps of New Zealand

Funding source

Swedish Research Council - Vetenskapsrådet (VR)

Project Details

Start date: 01/01/2017
End date: 31/12/2020
Funding: 2800000 SEK


The Southern Alps of New Zealand are an archetypal example of a mountain range whose growth has been guided by the development of a rain shadow. By controlling growth and architecture of the evolving Southern Alps, the rain shadow effect caused a marked orogenic asymmetry with a narrow, strongly eroding, steep western (windward) side exposing deep-seated rocks, and a broad, slowly eroding, low-relief topography on its eastern (leeward) side exposing near-surface rocks. It is unknown when the rain shadow formed. We will answer this important question through a field study constraining the cooling history of rocks and detrial zircon fission track dating on the windward side, and systematic fault gouge dating and stable isotope work on the leeside. We will also run numerical thermo-kinematic simulations for finding a best-fit kinematic model for the Southern Alps. The outcomes will shed new light on the long-standing debate on how rain shadows influence mountain growth and how to date their inception. The series of four major earthquakes near Christchurch in 2010/11 is a manifestation of climate-driven eastward propagation of the Southern Alps and we will establish rates for eastward growth, thereby showing new and innovative links between climate, mountain building and natural hazards. International significance of the project is highlighted by awarding the 2014 Crafoord Prize to Peter Molnar, who focused much of his career on climate/tectonics interactions in the Himalaya.

Last updated on 2017-05-10 at 07:24

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