Tectonics and formation of the Southern Alps

New Zealand sits on the famous “Ring of Fire”, which is one of the reasons for its astounding natural diversity and why this country has some of the most beautiful mountain ranges in the world – The Southern Alps, dominating the South Island along its West Coast and only a few km at places from the Tasman Sea. But it is also the reason why this magnificent country is very prone to the earthquakes.

The Earth’s crust is made of a number of separate sections called tectonic plates. New Zealand lies along the meeting of the Pacific plate on the east and Indo-Australian plate on the west. In the South Island, the plates form a straight and very active fault line that is about 500km long, stretching from Nelson Lakes National Park down to Mt. Aspiring National Park. The plates are moving both laterally and towards one another. As the Indo – Australian plate moves towards the North, the Pacific plate is being thrust up over it, forming the Southern Alps. This movement uplifts the Alps at about 10-20mm a year, making it one of the fastest rising mountains in the world. The rates of uplift are nearly matched by the rate of erosion. Without erosion the Southern Alps would today, after millions of years of uplift, dwarf Mount Everest significantly by extending 20km into the stratosphere.

Leave a Reply

Your email address will not be published. Required fields are marked *


9 − = three

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>