A new map reveals that six faults ruptured during the Nov. 14 Kaikoura earthquake in New Zealand.
The magnitude -7.8 quake ruptured at least four faults along the coast, as well as two inland. Arrows show the level of displacement along each of these faults.
The magnitude -7.5 quake that rattled New Zealand, killing at least two people and stranding thousands of people, completely transformed the underlying faults in the region. In overall, six major faults ruptured as a result of the New Zealand quake.
The Kaikoura earthquake struck the South Island of New Zealand early in the morning on Nov. 14 local time, triggering landslides, tsunamis and hundreds of aftershocks. During the quake, bystanders captured images of mysterious earthquake lights painting the sky in eerie blue and green.
To see how the massive temblor reshaped the landscape, scientists flew over the South Island in a helicopter to take video footage of the region. The team compared before-and-after images of the faults in the area. It turned out the temblor had dramatically changed the earth beneath.
Four faults along the coastline ruptured and extended out into the sea, while another two faults ruptured inland, closer to the epicenter of the quake. Ground-based GPS stations also reveal major motion at these faults.
The whole coast appears to have been uplifted from Cape Campbell all the way south to Kaikoura. The ones right on the coast appear to have very large movements, almost 1 meter [3.3 feet] up and almost 3 m [10 feet].
It’s a really complicated area and there are a lot of faults here, so the earthquake will have relieved the stress in some places, but unfortunately will have increased the stress in others. That’s what we are desperately trying to figure out now — what might have been loaded up.
The next step is to take ships out to send sound waves beneath the water to map the seafloor. By comparing before-and-after seafloor maps, geologists can determine how far offshore the ruptures extend. That, in turn, will help reveal where faults are newly locked and loaded.