6.1

M6.1 Earthquake in the Kermadec Islands region — July 24, 2021

2021-07-24 12:51:28 UTC (2021-07-24) · approx. 12:51 AM UTC-12 local

Felt by 11 people across nearby locations.

MagnitudeM6.1(mww)
Time12:51 UTC≈ 12:51 AM UTC-12
Depth10.0 kmshallow crustal
Coordinates-29.927°, -176.864°
Felt by11DYFI responses· max MMI 2.6
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On July 24, 2021 at 12:51 UTC, a magnitude 6.1 shallow crustal earthquake struck in the Kermadec Islands region, at a depth of 10.0 km and coordinates -29.9271°, -176.8643°. The earthquake was reported felt by 11 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.6 (weak). 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 6.1 releases seismic energy equivalent to roughly 21 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 9.7 km — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -29.93°, -176.86°

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.

USGS ShakeMap intensity contours for the M6.1 earthquake near Kermadec Islands region

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 11 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M6.1 earthquake near Kermadec Islands region

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
6.1 mww
Depth
10.0 km
shallow crustal
Location
-29.9271°N
-176.8643°E
Felt Reports
11
DYFI responses
Intensity (MMI)
2.6
weak
Community Intensity
2.0
CDI from reports

Technical Information

Event ID
us6000eynb
Event Type
earthquake
Status
✓ Reviewed
Significance
575
Azimuthal Gap
57.0°
Min Station Distance
10.040°
RMS Residual
0.41 sec
Last Updated
2025-12-22 22:12:02 UTC

Common Questions

How strong was the magnitude 6.1 earthquake in the Kermadec Islands region?

The magnitude 6.1 earthquake that struck in the Kermadec Islands region on July 24, 2021 at 12:51 UTC had a depth of 10.0 km. It was felt by 11 people with maximum shaking intensity of MMI 2.6 (weak). For context, this was a strong earthquake capable of causing significant damage.

Where did the earthquake occur?

The earthquake epicenter was located at -29.9271°, -176.8643°, which is in the Kermadec Islands region.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.1 earthquakes can continue for weeks to months and gradually diminish over time.

Authoritative source: USGS event page (event ID: us6000eynb). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, July 24, 2021). M6.1 Earthquake in the Kermadec Islands region — July 24, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000eynb/