M3.3 Earthquake 4 km E of Waimairi Beach, New Zealand — April 20, 2023
2023-04-20 19:31:09 UTC (2023-04-20) · approx. 7:31 AM UTC+12 local
On April 20, 2023 at 19:31 UTC, a magnitude 3.3 shallow crustal earthquake struck 4 km E of Waimairi Beach, New Zealand, at a depth of 17.4 km and coordinates -43.4802°, 172.7814°.
Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 114 m — a useful intuition for the size of the slip patch on the fault.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 3 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
172.7814°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.3 earthquake near Waimairi Beach, New Zealand?
The magnitude 3.3 earthquake that struck 4 km E of Waimairi Beach, New Zealand on April 20, 2023 at 19:31 UTC had a depth of 17.4 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.3 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.3 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000k5uv). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, April 20, 2023). M3.3 Earthquake 4 km E of Waimairi Beach, New Zealand — April 20, 2023. Retrieved July 3, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000k5uv/