NZ quake changed landscape
INCREDIBLE images showing the fractures in the landscape wrought by the November 14 7.8 Kaikoura earthquake have been captured by scientists working in New Zealand's North Canterbury region.
Dr Kate Pedley, of University of Canterbury's Department of Geological Sciences, shared on Facebook some of the dramatic sights she and her colleagues have encountered as they've surveyed evidence of faulting in the countryside.
Dr Pedley said the survey area covered a "complicated 3km wide zone” of numerous ruptures and associated structures.
"Thankfully, those south and west of Waiau generally got off lightly, but it very quickly got messy for infrastructure to the north-east,” she wrote.
"The number of associated rockfall, landslides and slumps were incredible.”
Meanwhile, geologists Tim Little of Victoria University of Wellington and Russ Van Dissen of GNS Science have been investigating the area's Kekerengu Fault, which they'd previously found was likely to be the fastest slipping fault within 100km of Wellington city, apart from the Hikurangi subduction zone.
They knew this meant it posed a significant seismic hazard to the north-eastern South Island and also to Wellington if linking faults in Cook Strait ruptured at the same time as the Kekerengu Fault.
In February this year, the pair excavated trenches across the fault to look for evidence of past large earthquakes
In these trenches, they found evidence of at least three past large earthquakes in the past 1250 years. These initial results confirmed that the fault was capable of producing large earthquakes frequently - on average, every 300 to 400 years - and was likely to do so again.
The recent earthquake's impacts on the landscape were dramatic, GNS Science earthquake geologist Dr Ursula Cochran said.
"One side of the fault had moved as much as 11m with respect to the other side.”
- NZ HERALD