Marc's Patented Tilt-A-Whirl Theory About the Christchurch Earthquakes

I was trying to illustrate better my boneheaded understanding of the geologic reports I was reading last week. It seemed to me that the Tilt-A-Whirl carnival ride is a useful analogy.

Picture the northern Canterbury Plains (which is carrying the City Of Christchurch) as one of the cars rotating counterclockwise in the YouTube video below – preferably one of the cars moving to the left, on the far side of the Tilt-A-Whirl (mimicking the movement of the Pacific Plate as it moves westwards to collide with the Australian Plate). The Greendale Fault, and the new fault made evident by the February quake are the visible portions of the circular base upon which the car sits.

As the car rotates, the circular base of the car slips to the right of the observer.

Similarly, as viewed from Diamond Harbour, the City of Christchurch slips to the right (and vice-versa: as seen from Christchurch, Diamond Harbour seems to slip to the right).



Here is a much better animation showing how New Zealand will be affected over the next four million years by the collisions between plates.