4.6

M4.6 Earthquake in the Fiji regionAugust 20, 2021

2021-08-20 21:20:52 UTC (2021-08-20) · approx. 9:20 AM UTC-12 local

MagnitudeM4.6(mb)
Time21:20 UTC9:20 AM UTC-12
Depth417.4 kmdeep-focus
Coordinates-19.169°, -177.426°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 20, 2021 at 21:20 UTC, a magnitude 4.6 deep-focus earthquake struck in the Fiji region, at a depth of 417.4 km and coordinates -19.1693°, -177.4263°.

Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Fiji, a region characterized by the Fiji Fracture Zone at the junction of the Pacific and Australian plates, with deep-focus seismicity from the subducted slab. View all earthquakes in Fiji.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at -19.17°, -177.43°

Earthquake Details

Magnitude
4.6 mb
Depth
417.4 km
deep-focus
Location
-19.1693°N
-177.4263°E

Technical Information

Event ID
us7000f6b8
Event Type
earthquake
Status
✓ Reviewed
Significance
326
Azimuthal Gap
80.0°
Min Station Distance
4.518°
RMS Residual
0.38 sec
Last Updated
2021-11-02 14:55:39 UTC

Common Questions

How strong was the magnitude 4.6 earthquake in the Fiji region?

The magnitude 4.6 earthquake that struck in the Fiji region on August 20, 2021 at 21:20 UTC had a depth of 417.4 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -19.1693°, -177.4263°, which is in the Fiji region. View all earthquakes in Fiji.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.

Authoritative source: USGS event page (event ID: us7000f6b8). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 20, 2021). M4.6 Earthquake in the Fiji regionAugust 20, 2021. Retrieved November 2, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000f6b8/