Shallow M6.1 earthquake hits Auckland Islands, M5.1 Cook Strait, New Zealand

A strong and shallow earthquake registered by the USGS as M6.1 hit Auckland Islands, New Zealand at 01:43 UTC (13:43 local time) on September 20, 2017. The quake hit at a depth of 10 km (6.2 miles). GFZ Potsdam (GEOFON) is reporting the same magnitude and depth. Just one hour later, a moderately strong M5.1 earthquake hit New Zealand's Cook Strait.

The M6.1 Auckland Islands quake hit just several hours after devastating M7.1 earthquake hit Mexico. 

According to the USGS, the epicenter was located 598.5 km (371.9 miles) SW of Bluff (population 1 938) and 615.7 km (382.6 miles) SW of Invercargill (population 47 287), New Zealand.

There are no people living within 100 km (62 miles).

This earthquake did not produce a tsunami.

M6.1 earthquake hits Auckland Islands at 01:43 UTC on September 20, 2017. Credit: USGS

USGS issued a green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.

Overall, the population in this region resides in structures that are highly resistant to earthquake shaking, though some vulnerable structures exist. The predominant vulnerable building types are reinforced masonry and unreinforced brick with timber floor construction.

At 02:42 UTC (14:42 local time) a moderately strong earthquake registered by GeoNet as M5.1 hit Cook Strait, between New Zealand's North and South Island. The quake occurred at a depth of 17 km (10.5 miles). 

The epicenter was located 30 km (18.6 miles) NE of Seddon. 

M5.1 earthquake (GeoNet) hits Cook Strait, New Zealand at 02:42 UTC on September 20, 2017. Credit: USGS

USGS registered this quake as M6.0 at a depth of 24.4 km (15 miles) and received 10 'I felt it' reports.

Featured image credit: USGS