M6.3 Earthquake in the Kermadec Islands region — March 5, 2021
2021-03-05 02:30:36 UTC (2021-03-05) · approx. 2:30 PM UTC-12 local
On March 5, 2021 at 02:30 UTC, a magnitude 6.3 shallow crustal earthquake struck in the Kermadec Islands region, at a depth of 17.0 km and coordinates -28.7490°, -176.5578°. 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 6.3 releases seismic energy equivalent to roughly 43 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 13 km — a useful intuition for the size of the slip patch on the fault.
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
Earthquake Details
-176.5578°E
Technical Information
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Common Questions
How strong was the magnitude 6.3 earthquake in the Kermadec Islands region?
The magnitude 6.3 earthquake that struck in the Kermadec Islands region on March 5, 2021 at 02:30 UTC had a depth of 17.0 km. For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at -28.7490°, -176.5578°, which is in the Kermadec Islands region.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.3 earthquakes can continue for weeks to months and gradually diminish over time.
Actions
Authoritative source: USGS event page (event ID: us7000dft1). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, March 5, 2021). M6.3 Earthquake in the Kermadec Islands region — March 5, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000dft1/