Major Quake, Kermadecs

A major undersea earthquake struck south of the Kermadec Islands this afternoon.

Monday, 10th September 2018

A magnitude 6.9 earthquake struck 61 km southwest of L’Esperance Rock in the Kermadec islands at 4:19 this afternoon, New Zealand Standard Time. The US Geological Survey reports that the earthquake was centred 729 km north-east of Whangarei, 757 km north-north-east of Whakatane at a depth of 111 km.
The Pacific Tsunami Warning Centre reported the earthquake as magnitude 7.0 at a depth of 134 km, noting that there was no tsunami threat from the quake.

GeoNet Tsunami Gauge Network 10 Sept 2018

GeoNet Tsunami Gauge Network 10 Sept 2018


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GeoNet’s tsunami gauge network showed no disturbance from the event.

GeoNet Seismograph Network 10 September 2018

GeoNet Seismograph Network 10 September 2018


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The earthquake left a significant trace on GeoNet’s national seismograph network which also captured the larger aftershocks.
GeoNet’s automatic reporting tool initially reported “ghost” quakes from Matawai to Twizel as a result of the earthquake. GeoNet has analysed the quake as magnitude 6.7 centred 785 km north-east of Whakatane at a depth of 132 km. Shaking from the earthquake was felt from Auckland to Christchurch with the public filing two thousand felt reports with GeoNet.

A number of aftershocks have followed the quake. The aftershock events reported by GeoNet are:
4:33 p.m., Mag 5.1, 126 km deep, 775 km NE of Whakatane
4:56 p.m., Mag 4.9, 153 km deep, 760 km NE of Whakatane
5:06 p.m., Mag 5.4, 94 km deep, 755 km NE of Whakatane
5:54 p.m., Mag 4.5, 100 km deep , 745 km NE of Whakatane
6:31 p.m., Mag 4.8, 100 km deep, 765 km NE of Whakatane

Other significant earthquakes in the region in recent weeks have included a very deep magnitude 8.2 earthquake near Fiji on August 19th and a magnitude 7.8 earthquake centred 101 km east-south-east of Suva, Fiji at 3:49 a.m. NZST on Saturday the 7th of September. This quake was also very deep, at 608 km. The Pacific Tsunami warning Centre reported Saturday’s earthquake as magnitude 8.1 at a depth of 670 km.

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