Coastal Uplift

Turakirae Head near Wellington is a world famous example of coastal tectonic uplift, where five storm ridges can be identified running parallel to the sea shore. Each one was pushed out of reach of the sea by sudden uplift during successive earthquakes over the last seven thousand years. Image: GNS Science, Lloyd Homer.

Turakirae Head near Wellington is a world famous example of coastal tectonic uplift, where five storm ridges can be identified running parallel to the sea shore. Each one was pushed out of reach of the sea by sudden uplift during successive earthquakes over the last seven thousand years. Image: GNS Science, Lloyd Homer.

Turakirae Head near Wellington is a world famous example of coastal tectonic uplift, where five storm ridges can be identified running parallel to the sea shore. These were created by powerful waves pushing boulders and pebbles up the beach into a pile along the high water line. Each ridge was then was pushed out of reach of the sea by sudden uplift during an earthquake. A new ridge then developed in front of the old one, until the area was again pushed up by another earthquake. These ridges hold a record of large earthquakes uplifting the area over the last seven thousand years.

Tectonic uplift around New Zealand has created many raised beaches and flat marine terraces that originated at sea level. They can be recognised as horizontal or gently tilted steps or platforms on many of our coastal hills

Successive earthquakes raise these higher and higher through time, so that the highest ones in a sequence are always the oldest. Fossils and carbon material found on these features allow them to be dated so that the local average rates of uplift can be calculated.