M5.1 Earthquake 206 km WSW of Riverton, New Zealand — February 23, 2021
2021-02-23 04:07:28 UTC (2021-02-23) · approx. 3:07 PM UTC+11 local
Felt by 16 people across nearby locations.
On February 23, 2021 at 04:07 UTC, a magnitude 5.1 shallow crustal earthquake struck 206 km WSW of Riverton, New Zealand, at a depth of 32.0 km and coordinates -47.3594°, 165.7473°.
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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 16 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
165.7473°E
Technical Information
Common Questions
How strong was the magnitude 5.1 earthquake near Riverton, New Zealand?
The magnitude 5.1 earthquake that struck 206 km WSW of Riverton, New Zealand on February 23, 2021 at 04:07 UTC had a depth of 32.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -47.3594°, 165.7473°, which is 206 km WSW of Riverton, 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: us6000dkb5). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, February 23, 2021). M5.1 Earthquake 206 km WSW of Riverton, New Zealand — February 23, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000dkb5/