Severe Quake shakes up Wellington Anniversary

On Monday afternoon at 15:52, an earthquake with a magnitude M6.2 struck at a depth of about 33km approximately 15 km east of Eketahuna in the Wairarapa

Summary

The Eketahuna quake struck at 3:52 pm on Monday afternoon, and was centered 15 km east of Eketahuna, under the south-east of the North Island. The quake was felt strongly in both islands,  and we have received over 9000 felt reports from the public, with multiple reports of damage. The focal mechanism shows it to be a normal fault earthquake.

An aftershock sequence is ongoing following this earthquake and includes numerous magnitude 4 events. As with any aftershock sequence, we cannot rule out the possibility of occurrence of future larger earthquakes.

What are the probabilities of future significant earthquakes?

 Up-to-date aftershock forecasts are now located on the 'Future Scenarios and Aftershocks' page in the News Section of our website.

 

Current Research

Current depth and location estimates of this event place it below the interface between the subducting Pacific plate and overriding Australian plate. Maximum peak ground acceleration recorded by GeoNet instruments is about one quarter of the acceleration due to gravity (0.26 g). This measurement was recorded in Woodville. Relatively strong shaking was also recorded on the Kapiti Coast (e.g. up to 0.2 g in Paraparaumu) whereas accelerations recorded in Wellington city were less than 0.05 g. In comparison, ground motions recorded in Wellington during the recent Cook Strait earthquakes ranged up to 0.26g.

The seismology team at GNS Science is also attempting to understand the earthquakes in the context of recent and ongoing seismicity. Specifically, efforts are aimed at comparing the current earthquakes with a sequence of events that occurred to the north of Eketahuna in the early 1990s. We are also considering possible links to the ongoing Kapiti slow-slip event.

The likelihood of a larger triggered event in the coming weeks is minor. However, it is possible and we should all take this opportunity to review our earthquake emergency plans.

 

What are the numbers so far?

Numbers of Eketahuna region earthquakes

Magnitude range15:52 pm, 20 January 2014 to
08:40 am, 27 January 2014*
6.0 - 6.91
5.0 - 5.90
4.0 - 4.98
3.0 - 3.975
below 3.01205
TOTAL1289
*This table will no longer be updated. Up-to-date aftershock tables are in 'Our News' section

GeoNet Response

 

 

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