5.8

M5.8 Earthquake 150 km WNW of Haveluloto, Tonga — October 22, 2020

2020-10-22 08:24:07 UTC (2020-10-22) · approx. 8:24 PM UTC-12 local

MagnitudeM5.8(mww)
Time08:24 UTC≈ 8:24 PM UTC-12
Depth244.0 kmintermediate depth
Coordinates-20.826°, -176.621°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On October 22, 2020 at 08:24 UTC, a magnitude 5.8 intermediate depth earthquake struck 150 km WNW of Haveluloto, Tonga, at a depth of 244.0 km and coordinates -20.8260°, -176.6209°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is `Ohonua (population 1,241).

Physical scale: An earthquake of magnitude 5.8 releases seismic energy equivalent to roughly 8 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 6.1 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

Nearest Populated Places

`Ohonuapop. 1,241
MMI 3.0 (light)
Vainipop. 2,976
MMI 3.2 (light)
Havelulotopop. 3,417
MMI 3.1 (light)
Nuku'alofapop. 22,400
MMI 3.2 (light)
Map showing earthquake epicenter at -20.83°, -176.62°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M5.8 earthquake near 150 km WNW of Haveluloto, Tonga

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak86,628

Earthquake Details

Magnitude
5.8 mww
Depth
244.0 km
intermediate depth
Location
-20.8260°N
-176.6209°E
Intensity (MMI)
3.2
light

Technical Information

Event ID
us6000cb8b
Event Type
earthquake
Status
✓ Reviewed
Significance
518
Azimuthal Gap
29.0°
Min Station Distance
5.890°
RMS Residual
0.80 sec
Last Updated
2025-12-22 18:45:22 UTC

Common Questions

How strong was the magnitude 5.8 earthquake near Haveluloto, Tonga?

The magnitude 5.8 earthquake that struck 150 km WNW of Haveluloto, Tonga on October 22, 2020 at 08:24 UTC had a depth of 244.0 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at -20.8260°, -176.6209°, which is 150 km WNW of Haveluloto, Tonga. The nearest populated place is `Ohonua (population 1,241). View all earthquakes in Tonga.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.8 earthquakes can continue for days to weeks 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 5.8 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000cb8b). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, October 22, 2020). M5.8 Earthquake 150 km WNW of Haveluloto, Tonga — October 22, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000cb8b/