Last night’s M5.1 quake off the east coast of the North Island

Published: Wed May 15 2019 12:30 PM

Last night’s M5.1 quake off the east coast of the North Island in the subducting Pacific Plate was similar to past earthquakes in this area.

The magnitude 5.1 quake was 29 kilometres deep and 371 people filled in a felt report.

M5.1 earthquake offshore of the east coast

M5.1 earthquake offshore of the east coast

Our scientists have been closely studying quakes in the Hikurangi Subduction Zone region to build more understanding of what processes are at play, and what this means for the New Zealand public.

We’ve been updating you on the progress of a slow-slip event since the start of April 2019. We typically see higher rates of earthquake activity during slow-slip events in New Zealand. This earthquake may be related to the ongoing slow-slip event off the east coast.

We’ve got instruments offshore gathering data on offshore quakes and land movements to help us understand more about these-slow slip events. These instruments will pick up on the increased local seismic activity that we are seeing as a result of the slow-slip event off the coast of Gisborne and Hawke’s Bay.

GeoNet has been registering slow-slip activity since our GPS network was deployed in 2002. Since then, we’ve seen slow-slip events in this area every 1-2 years, with larger events every 4-6 years. This event is currently about the size of the previous largest slow-slip event we recorded in early 2010.

Remember that if you feel earthquake shaking to DROP, COVER and HOLD. If you are close to the water, once shaking stops, immediately get to higher ground out of all tsunami evacuation zones or as far inland as you can. Remember, if you feel a LONG OR STRONG quake GET GONE in case a tsunami follows. Long is considered longer than a minute, and strong is classified as hard to stand up.

Here are some links to articles on the Hikurangi Subduction Zone and our previous slow-slip event updates:

Slow-slip event off the coast of Gisborne

East Coast slow-slip event update

Some facts about the Hikurangi subduction zone - New Zealand’s largest plate boundary fault

From East Coast LAB

Hikurangi Subduction Earthquakes & Slip Behaviour

Attributable to - Dr Jonathan Hanson – Duty Seismologist

Media enquiries - media@gns.cri.nz or 021 574 541