4.7

M4.7 Earthquake near TongaMay 18, 2023

2023-05-18 19:43:25 UTC (2023-05-18) · approx. 7:43 AM UTC-12 local

MagnitudeM4.7(mb)
Time19:43 UTC7:43 AM UTC-12
Depth149.0 kmintermediate depth
Coordinates-20.051°, -175.438°
Felt byNo felt reports
Status✓ Reviewed by USGS

On May 18, 2023 at 19:43 UTC, a magnitude 4.7 intermediate depth earthquake struck near Tonga, at a depth of 149.0 km and coordinates -20.0506°, -175.4378°. This earthquake was detected by 58 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.

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.

The epicenter is located in Tonga, a region characterized by the Tonga-Kermadec subduction zone, where the Pacific Plate descends at up to 240 mm per year — the fastest plate convergence on Earth. The nearest mapped fault system is the Tonga Trench. View all earthquakes in Tonga.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at -20.05°, -175.44°

Earthquake Details

Magnitude
4.7 mb
Depth
149.0 km
intermediate depth
Location
-20.0506°N
-175.4378°E

Technical Information

Event ID
us6000kcxq
Event Type
earthquake
Status
✓ Reviewed
Significance
340
Stations Used
58
Azimuthal Gap
36.0°
Min Station Distance
1.048°
RMS Residual
0.89 sec
Last Updated
2023-07-24 01:16:11 UTC

Common Questions

How strong was the magnitude 4.7 earthquake near Tonga?

The magnitude 4.7 earthquake that struck near Tonga on May 18, 2023 at 19:43 UTC had a depth of 149.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -20.0506°, -175.4378°, which is near Tonga. View all earthquakes in Tonga.

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.

Has Tonga had earthquakes this big before?

The largest recorded earthquake in Tonga was the M8.1 Tonga Trench earthquake of June 26, 1917. Today's magnitude 4.7 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000kcxq). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, May 18, 2023). M4.7 Earthquake near TongaMay 18, 2023. Retrieved July 24, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000kcxq/