Reviewed by USGSTonga3d ago
M5.7 earthquake 180 km NW of Hihifo, Tonga
Wednesday, September 23, 2026, 14:41:02 UTC · 14.937°S, 175.111°W
A magnitude 5.7 earthquake struck 180 km NW of Hihifo, Tonga on Wednesday, September 23, 2026, 14:41:02 UTC, at a depth of 10.0 km (shallow). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M6.1 on April 19, 2026.
- Magnitude
- 5.7
- Moderate · mww
- Depth
- 10 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- IV
- Light (ShakeMap)
- PAGER alert
- Green
- Impact estimate
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
5 kilotons of TNT
That is about 1/3 of the Hiroshima bomb. It released about 11 times the energy of a magnitude 5.0.
Tectonic setting
61 km
from the nearest mapped plate boundary, between the Pacific and Niuafo'ou plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No populated area was estimated to feel noticeable shaking.
After the main event
Aftershocks within 75 km
USGS lists 1 M2.5+ earthquake within 75 km since this event; the largest was M4.9 on September 23, 2026. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,704 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0The 1917 Samoa-Tonga EarthquakeJune 26, 1917 · 198 km E of this epicenter
- 7.7133 km NE of Hihifo, TongaSeptember 1, 1981 · 218 km E of this epicenter
- 7.682 km WNW of Hihifo, TongaMay 10, 2023 · 102 km SE of this epicenter
- 7.488 km NNE of Hihifo, TongaApril 7, 1995 · 172 km E of this epicenter
- 7.2117 km SSW of Hihifo, TongaJanuary 8, 2000 · 240 km SE of this epicenter
- 7.219 km ENE of Hihifo, TongaOctober 15, 1984 · 188 km SE of this epicenter
- 7.1112 km NNE of Hihifo, TongaApril 14, 1957 · 186 km E of this epicenter
- 6.9127 km S of Hihifo, TongaMay 8, 1913 · 268 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2 recorded deaths. The most severe:
- 1917M8.3
Samoa Islands
26 Jun 1917 · 235 km away
2 deathsModerate damage ($1–5M)tsunami
- 1981M7.7
Apia; American Samoa: Pago Pago
1 Sep 1981 · 218 km away · intensity VI
Limited damage (under $1M)tsunami
- 2023M7.6
Hihifo
10 May 2023 · 91 km away
- 1957M7.5
Samoa Islands
14 Apr 1957 · 235 km away
- 1995M7.4
Apia; American Samoa: Pago Pago; Niue
7 Apr 1995 · 172 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.