Reviewed by USGSTonga114y ago
M7.8 earthquake 111 km SSE of Pangai, Tonga
Thursday, June 26, 1913, 04:57:18 UTC · 20.680°S, 173.808°W
A magnitude 7.8 earthquake struck 111 km SSE of Pangai, Tonga on Thursday, June 26, 1913, 04:57:18 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M8.0 on January 4, 1903.
- Magnitude
- 7.8
- Major · mw
- Depth
- 25 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
7.3 megatons of TNT
That is about 485 times the Hiroshima bomb. It released about 15,311 times the energy of a magnitude 5.0.
Tectonic setting
34 km
from the nearest mapped plate boundary, between the Tonga and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
25 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 PAGER estimate is available for this event.
After the main event
Aftershocks within 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 6 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 145 km NW of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 186 km N of this epicenter
- 7.2108 km SE of Neiafu, TongaDecember 19, 1906 · 175 km NE of this epicenter
- 6.915 km WSW of Pangai, TongaFebruary 27, 1905 · 115 km NW of this epicenter
- 6.5TongaDecember 18, 1906 · 116 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1865M8.0
Tonga Islands
18 Nov 1865 · 135 km away
Limited damage (under $1M)tsunami
- 1903M8.0
Tonga Islands
4 Jan 1903 · 145 km away
- 1902M7.8
Tonga Islands
9 Feb 1902 · 78 km away
- 1913M7.6
Tonga Islands
26 Jun 1913 · 78 km away
- 1853
Tonga Trench
24 Dec 1853 · 151 km away
tsunami
- 1907
S Of Tonga
1907 · 207 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.