M7.2 Earthquake 274 km SW of Houma, Tonga — June 15, 2023
2023-06-15 18:06:28 UTC (2023-06-15) · approx. 6:06 AM UTC-12 local
Felt by 10 people across nearby locations. Maximum shaking intensity MMI 6.1 (very strong).
On June 15, 2023 at 18:06 UTC, a magnitude 7.2 intermediate depth earthquake struck 274 km SW of Houma, Tonga, at a depth of 179.0 km and coordinates -22.9936°, -177.1067°. The earthquake was reported felt by 10 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 6.1 (very strong). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 146 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 805, making it one of the more significant events of the week.
Physical scale: An earthquake of magnitude 7.2 releases seismic energy equivalent to roughly 951 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 56 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
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.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 10 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
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) | Description | Population exposed |
|---|---|---|
| MMI 4 | light | 92,799 |
Earthquake Details
-177.1067°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 7.2 earthquake near Houma, Tonga?
The magnitude 7.2 earthquake that struck 274 km SW of Houma, Tonga on June 15, 2023 at 18:06 UTC had a depth of 179.0 km. It was felt by 10 people with maximum shaking intensity of MMI 6.1 (very strong). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at -22.9936°, -177.1067°, which is 274 km SW of Houma, Tonga. View all earthquakes in Tonga.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 7.2 earthquakes can continue for months to years 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 7.2 event is within one magnitude unit of that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000k8qh). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, June 15, 2023). M7.2 Earthquake 274 km SW of Houma, Tonga — June 15, 2023. Retrieved August 21, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000k8qh/