A magnitude-6.6 earthquake struck New Zealand's South Island on Friday, shattering windows, cracking chimneys and walls and damaging two bridges near Seddon, the city closest to the quake's epicenter. Shaking was also felt strongly on the country's North Island, in the capital city of Wellington which lies just across the Cook Strait from Seddon. Workers escaping the city after the earthquake created massive gridlock in Wellington, according to news reports. No serious injuries have been reported.
The quake hit 6.7 miles (10.8 kilometers) southeast of Seddon just after 2:30 p.m. local time Friday (9:30 p.m. EST on Thursday, Aug. 15). It was centered at a relatively shallow depth of 5 miles (8 km), according to GeoNet, New Zealand's geological hazards monitoring network. Several aftershocks followed, the strongest a magnitude-6.0.
The temblor, named the Lake Grassmere earthquake by GeoNet, appears to be a strike-slip quake, during which two blocks of Earth's crust slide past one another with little vertical movement. Friday's quake is the second big strike-slip earthquake to rattle the Cook Strait in less than a month. On July 21, a magnitude-6.5 earthquake struck offshore of Seddon. Several strike-slip faults cross the Cook Strait onshore and offshore between the South Island and North Island, according to GeoNet.