4.2

M4.2 Earthquake 50 km SW of Leava, Wallis and FutunaSeptember 23, 2021

2021-09-23 18:32:05 UTC (2021-09-23) · approx. 6:32 AM UTC-12 local

MagnitudeM4.2(mb)
Time18:32 UTC6:32 AM UTC-12
Depth435.7 kmdeep-focus
Coordinates-14.554°, -178.543°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 23, 2021 at 18:32 UTC, a magnitude 4.2 deep-focus earthquake struck 50 km SW of Leava, Wallis and Futuna, at a depth of 435.7 km and coordinates -14.5542°, -178.5429°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -14.55°, -178.54°

Earthquake Details

Magnitude
4.2 mb
Depth
435.7 km
deep-focus
Location
-14.5542°N
-178.5429°E

Technical Information

Event ID
us7000ff7j
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Azimuthal Gap
133.0°
Min Station Distance
0.476°
RMS Residual
0.39 sec
Last Updated
2021-12-03 15:02:11 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Leava, Wallis and Futuna?

The magnitude 4.2 earthquake that struck 50 km SW of Leava, Wallis and Futuna on September 23, 2021 at 18:32 UTC had a depth of 435.7 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000ff7j). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, September 23, 2021). M4.2 Earthquake 50 km SW of Leava, Wallis and FutunaSeptember 23, 2021. Retrieved December 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000ff7j/