4.7

M4.7 Earthquake southeast of the Loyalty Islands — August 8, 2021

2021-08-08 16:50:07 UTC (2021-08-08) · approx. 3:50 AM UTC+11 local

MagnitudeM4.7(mb)
Time16:50 UTC≈ 3:50 AM UTC+11
Depth10.0 kmshallow crustal
Coordinates-22.947°, 171.505°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 8, 2021 at 16:50 UTC, a magnitude 4.7 shallow crustal earthquake struck southeast of the Loyalty Islands, at a depth of 10.0 km and coordinates -22.9465°, 171.5046°.

Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -22.95°, 171.50°

Earthquake Details

Magnitude
4.7 mb
Depth
10.0 km
shallow crustal
Location
-22.9465°N
171.5046°E

Technical Information

Event ID
us6000f7j2
Event Type
earthquake
Status
✓ Reviewed
Significance
340
Azimuthal Gap
119.0°
Min Station Distance
3.759°
RMS Residual
0.70 sec
Last Updated
2021-10-23 15:46:46 UTC

Common Questions

How strong was the magnitude 4.7 earthquake southeast of the Loyalty Islands?

The magnitude 4.7 earthquake that struck southeast of the Loyalty Islands on August 8, 2021 at 16:50 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -22.9465°, 171.5046°, which is southeast of the Loyalty Islands.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 earthquakes can continue for several days and gradually diminish over time.

Authoritative source: USGS event page (event ID: us6000f7j2). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 8, 2021). M4.7 Earthquake southeast of the Loyalty Islands — August 8, 2021. Retrieved October 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f7j2/