To feel the earth move under your feet, visit New Zealand. Every year the sides of the island nation's Alpine Fault shift past one another about 30 millimeters—a blistering speed for strike-slip faults, which typically slip at rates closer to one or two millimeters a year. “What is particularly interesting about the Alpine Fault is that it has maintained this high slip rate for almost its entire history,” says Simon Lamb, a geologist at the Victoria University of Wellington. “As far as I can tell, no other one land fault comes close in this respect.” In fact, the Alpine Fault has shifted approximately 700 kilometers over the past 25 million years—250 kilometers more than previously estimated, according to Lamb's new study in Geochemistry, Geophysics, Geosystems. That movement has seismic consequences: New Zealand has a 30 percent chance for an earthquake of magnitude eight or higher in the next 50 years.

 

Top 5 Fastest-Moving Strike-Slip Faults
FAULT NAME LOCATION LENGTH
(km)
SLIP RATE
(mm/yr)
Alpine South Island,
New Zealand
700 30
San Andreas California 1,100 25
North Anatolian Turkey 1,100 20
Denali British Columbis
to Central Alaska
2,000 10
Altyn Tagh Tibet 1,500 9