Paul Gorman writes in The Press about a west Coast tree stump which suggests that the Alpine Fault is moving faster than previously thought.
Calculations based on when the tree died show that, rather than the Alpine Fault’s slip rate being 10 mm a year, it may in fact be moving some 13.6 mm a year (on average).
An excerpt: (read in full here)
“The latest calculations, based on when the stump died as a result of an earthquake, show it is moving at an average 13.6mm a year, plus or minus 1.8mm. That equates to about an extra metre of movement each time the fault ruptures – about every 300 years.
“The Alpine Fault is the boundary between the Australian and Pacific plates, which are moving past and pushing against each other, forcing the Southern Alps higher.
“The last time the fault moved was about 1717, generating an earthquake of at least magnitude 8.0.”