Reviewed by USGSTonga48y ago
M5.4 earthquake 184 km SE of Hihifo, Tonga
Tuesday, June 27, 1978, 14:44:45 UTC · 17.096°S, 172.534°W
A magnitude 5.4 earthquake struck 184 km SE of Hihifo, Tonga on Tuesday, June 27, 1978, 14:44:45 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on June 25, 1978.
- Magnitude
- 5.4
- Moderate · ms
- Depth
- 33 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 earthquakeDashed circle: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
2 kilotons of TNT
That is about 1/8 of the Hiroshima bomb. It released about 4 times the energy of a magnitude 5.0.
Tectonic setting
19 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
33 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 75 km
USGS lists 4 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.4 on July 8, 1978. 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 390 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11919 Tonga EarthquakeApril 30, 1919 · 137 km S of this epicenter
- 8.0The 1917 Samoa-Tonga EarthquakeJune 26, 1917 · 246 km N of this epicenter
- 7.8146 km ESE of Hihifo, TongaDecember 26, 1975 · 93 km N of this epicenter
- 7.6199 km ESE of Hihifo, TongaApril 2, 1977 · 64 km NE of this epicenter
- 7.4103 km ESE of Neiafu, TongaFebruary 27, 1921 · 208 km S of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 234 km S of this epicenter
- 7.2108 km SE of Neiafu, TongaDecember 19, 1906 · 246 km S of this epicenter
- 7.1112 km NNE of Hihifo, TongaApril 14, 1957 · 248 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 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 · 184 km away
2 deathsModerate damage ($1–5M)tsunami
- 1919M8.1
Tonga Islands
30 Apr 1919 · 140 km away
Limited damage (under $1M)tsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 286 km away
Limited damage (under $1M)tsunami
- 1977M7.6
Apia
2 Apr 1977 · 64 km away · intensity VI
Limited damage (under $1M)tsunami
- 1975M7.8
Samoa Islands
26 Dec 1975 · 93 km away · intensity V
tsunami
- 1957M7.5
Samoa Islands
14 Apr 1957 · 184 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.