4.3

M4.3 Earthquake 31 km ESE of Hihifo, TongaOctober 15, 2021

2021-10-15 23:14:29 UTC (2021-10-15) · approx. 11:14 AM UTC-12 local

MagnitudeM4.3(mb)
Time23:14 UTC11:14 AM UTC-12
Depth107.1 kmintermediate depth
Coordinates-16.081°, -173.530°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 15, 2021 at 23:14 UTC, a magnitude 4.3 intermediate depth earthquake struck 31 km ESE of Hihifo, Tonga, at a depth of 107.1 km and coordinates -16.0812°, -173.5297°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -16.08°, -173.53°

Earthquake Details

Magnitude
4.3 mb
Depth
107.1 km
intermediate depth
Location
-16.0812°N
-173.5297°E

Technical Information

Event ID
us6000fw61
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Azimuthal Gap
124.0°
Min Station Distance
2.741°
RMS Residual
0.65 sec
Last Updated
2021-12-25 22:58:53 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Hihifo, Tonga?

The magnitude 4.3 earthquake that struck 31 km ESE of Hihifo, Tonga on October 15, 2021 at 23:14 UTC had a depth of 107.1 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 4.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000fw61). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 15, 2021). M4.3 Earthquake 31 km ESE of Hihifo, TongaOctober 15, 2021. Retrieved December 25, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fw61/