4.9

M4.9 Earthquake 45 km NNE of Pangai, Tonga — October 2, 2020

2020-10-02 17:12:58 UTC (2020-10-02) · approx. 5:12 AM UTC-12 local

Felt by 1 person across nearby locations.

MagnitudeM4.9(mb)
Time17:12 UTC≈ 5:12 AM UTC-12
Depth35.0 kmshallow crustal
Coordinates-19.431°, -174.189°
Felt by1DYFI response
Status✓ Reviewed by USGS

On October 2, 2020 at 17:12 UTC, a magnitude 4.9 shallow crustal earthquake struck 45 km NNE of Pangai, Tonga, at a depth of 35.0 km and coordinates -19.4313°, -174.1890°.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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 -19.43°, -174.19°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.9 earthquake near 45 km NNE of Pangai, Tonga

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.9 mb
Depth
35.0 km
shallow crustal
Location
-19.4313°N
-174.1890°E
Felt Reports
1
DYFI responses
Community Intensity
2.2
CDI from reports

Technical Information

Event ID
us6000c4xg
Event Type
earthquake
Status
✓ Reviewed
Significance
370
Azimuthal Gap
47.0°
Min Station Distance
4.041°
RMS Residual
0.90 sec
Last Updated
2020-12-12 22:28:35 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Pangai, Tonga?

The magnitude 4.9 earthquake that struck 45 km NNE of Pangai, Tonga on October 2, 2020 at 17:12 UTC had a depth of 35.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -19.4313°, -174.1890°, which is 45 km NNE of Pangai, Tonga. View all earthquakes in Tonga.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000c4xg). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, October 2, 2020). M4.9 Earthquake 45 km NNE of Pangai, Tonga — October 2, 2020. Retrieved December 12, 2020 from https://www.earthquaketracker.org/earthquakes/event/us6000c4xg/