M4.9 Earthquake 132 km W of Riverton, New Zealand — February 21, 2026
2026-02-21 23:55:04 UTC (2026-02-21) · approx. 10:55 AM UTC+11 local
Felt by 1 person across nearby locations.
On February 21, 2026 at 23:55 UTC, a magnitude 4.9 shallow crustal earthquake struck 132 km W of Riverton, New Zealand, at a depth of 35.0 km and coordinates -46.2145°, 166.3093°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.8 (light). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 25 seismic stations with good location accuracy and was assigned a USGS significance rating of 370, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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 1 citizen response 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
166.3093°E
Technical Information
Common Questions
How strong was the magnitude 4.9 earthquake near Riverton, New Zealand?
The magnitude 4.9 earthquake that struck 132 km W of Riverton, New Zealand on February 21, 2026 at 23:55 UTC had a depth of 35.0 km. It was felt by 1 person with maximum shaking intensity of MMI 3.8 (light). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -46.2145°, 166.3093°, which is 132 km W 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 4.9 earthquakes can continue for several days 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 4.9 event is significantly smaller than that historical record.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Authoritative source: USGS event page (event ID: us6000sapq). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, February 21, 2026). M4.9 Earthquake 132 km W of Riverton, New Zealand — February 21, 2026. Retrieved May 12, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000sapq/