The quake happened at 9:21 a.m. GMT, with an epicentre 91 kilometres (56.5 miles) east of L'Esperance Rock at a depth of about 10 kilometres (6 miles), USGS reported. In the meantime, the Geophysical Service of the Russian Academy of Sciences has estimated the quake in the area to have a 5.9 magnitude.
There are no reports about any damage, or victims caused by the earthquake. No tsunami warning has been declared.
Parts of New Zealand lie on the so-called Ring of Fire, a horseshoe-shaped string of volcanoes around the Pacific Rim, where about 90 percent of the world's quakes occur.