M5.1 Earthquake near Kermadec Islands, New Zealand — September 20, 2023
2023-09-20 02:38:32 UTC (2023-09-20) · approx. 2:38 PM UTC-12 local
On September 20, 2023 at 02:38 UTC, a magnitude 5.1 shallow crustal earthquake struck near Kermadec Islands, New Zealand, at a depth of 49.9 km and coordinates -29.7599°, -177.6606°. This earthquake was detected by 29 seismic stations with good location accuracy and was assigned a USGS significance rating of 400, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.1 releases seismic energy equivalent to roughly 674 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.0 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
Earthquake Details
-177.6606°E
Technical Information
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Common Questions
How strong was the magnitude 5.1 earthquake near Kermadec Islands, New Zealand?
The magnitude 5.1 earthquake that struck near Kermadec Islands, New Zealand on September 20, 2023 at 02:38 UTC had a depth of 49.9 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -29.7599°, -177.6606°, 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 5.1 earthquakes can continue for days to weeks 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 5.1 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000ky5h). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 20, 2023). M5.1 Earthquake near Kermadec Islands, New Zealand — September 20, 2023. Retrieved December 2, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000ky5h/