M6.4 Earthquake near Kermadec Islands, New Zealand — August 31, 2021
2021-08-31 02:52:50 UTC (2021-08-31) · approx. 2:52 PM UTC-12 local
Felt by 5 people across nearby locations.
On August 31, 2021 at 02:52 UTC, a magnitude 6.4 shallow crustal earthquake struck near Kermadec Islands, New Zealand, at a depth of 16.0 km and coordinates -29.9211°, -177.3798°. The earthquake was reported felt by 5 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.7 (light). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected.
Physical scale: An earthquake of magnitude 6.4 releases seismic energy equivalent to roughly 60 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 16 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in New Zealand, a region characterized by the Hikurangi subduction zone in the North Island and the Alpine Fault in the South Island. The nearest mapped fault system is the Alpine Fault. View all earthquakes in New Zealand.
Learn more: Magnitude scale · Aftershock sequences
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 5 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-177.3798°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 6.4 earthquake near Kermadec Islands, New Zealand?
The magnitude 6.4 earthquake that struck near Kermadec Islands, New Zealand on August 31, 2021 at 02:52 UTC had a depth of 16.0 km. It was felt by 5 people with maximum shaking intensity of MMI 3.7 (light). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at -29.9211°, -177.3798°, which is near Kermadec Islands, New Zealand. View all earthquakes in New Zealand.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.4 earthquakes can continue for weeks to months and gradually diminish over time.
Has New Zealand had earthquakes this big before?
The largest recorded earthquake in New Zealand was the M8.2 Wairarapa earthquake of January 23, 1855. Today's magnitude 6.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000f60j). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, August 31, 2021). M6.4 Earthquake near Kermadec Islands, New Zealand — August 31, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000f60j/