Reviewed by USGS57y ago
M7.3 earthquake south of the Fiji Islands
Tuesday, January 20, 1970, 07:19:48 UTC · 25.908°S, 177.227°W
A magnitude 7.3 earthquake struck south of the Fiji Islands on Tuesday, January 20, 1970, 07:19:48 UTC, at a depth of 50.3 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on December 18, 1963.
- Magnitude
- 7.3
- Major · mw
- Depth
- 50 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
1.3 megatons of TNT
That is about 83 times the Hiroshima bomb. It released about 2,630 times the energy of a magnitude 5.0.
Tectonic setting
55 km
from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
50 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 106 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6south of the Fiji IslandsDecember 18, 1963 · 135 km N of this epicenter
- 7.2south of the Fiji IslandsNovember 24, 1960 · 169 km NE of this epicenter
- 7.0south of TongaJanuary 10, 1956 · 207 km E of this epicenter
- 6.8Kermadec Islands regionSeptember 15, 1959 · 300 km S of this epicenter
- 6.8south of the Fiji IslandsJuly 4, 1963 · 89 km SW of this epicenter
- 6.7south of the Fiji IslandsSeptember 8, 1920 · 187 km NE of this epicenter
- 6.7Kermadec Islands regionNovember 24, 1941 · 275 km S of this epicenter
- 6.7Kermadec Islands regionDecember 12, 1928 · 270 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 289 km away
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 289 km away
- 1963M7.5
Tonga Trench
18 Dec 1963 · 138 km away
tsunami
- 1956M7.0
Tonga Islands
10 Jan 1956 · 199 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.