Reviewed by USGS44y ago
M7.2 earthquake south of Tonga
Sunday, December 19, 1982, 17:43:54 UTC · 24.133°S, 175.864°W
A magnitude 7.2 earthquake struck south of Tonga on Sunday, December 19, 1982, 17:43:54 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M7.2 on October 10, 1977.
- Magnitude
- 7.2
- Major · mw
- Depth
- 33 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- IV
- Light (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
951 kilotons of TNT
That is about 63 times the Hiroshima bomb. It released about 1,995 times the energy of a magnitude 5.0.
Tectonic setting
28 km
from the nearest mapped plate boundary, between the Kermadec and Tonga 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 200 km
USGS lists 64 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.3 on December 20, 1982. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.7265 km SSW of ‘Ohonua, Tonga44y ago · 62 km N of this epicenter
- 5.4south of Tonga44y ago · 53 km SE of this epicenter
- 5.3south of Tonga44y ago · 48 km S of this epicenter
- 5.0235 km SSW of ‘Ohonua, Tonga44y ago · 91 km NE of this epicenter
- 5.3south of Tonga44y ago · 94 km E of this epicenter
- 5.0south of the Fiji Islands44y ago · 132 km W of this epicenter
- 5.6268 km SSW of ‘Ohonua, Tonga44y ago · 57 km NE of this epicenter
- 5.1260 km SSW of ‘Ohonua, Tonga44y ago · 68 km NE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 331 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8south of TongaOctober 11, 1975 · 113 km SE of this epicenter
- 7.6south of the Fiji IslandsDecember 18, 1963 · 121 km SW of this epicenter
- 7.4south of TongaMarch 18, 1905 · 251 km E of this epicenter
- 7.3south of the Fiji IslandsJanuary 20, 1970 · 240 km SW of this epicenter
- 7.2south of the Fiji IslandsNovember 24, 1960 · 72 km SW of this epicenter
- 7.2south of TongaOctober 10, 1977 · 197 km S of this epicenter
- 7.0south of TongaJanuary 10, 1956 · 263 km S of this epicenter
- 6.8Tonga regionJune 22, 1977 · 140 km N 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, which together caused about 1 recorded deaths. The most severe:
- 1977M7.2
Tonga Trench
22 Jun 1977 · 140 km away · intensity IV
1 death$1 million damagetsunami
- 1975M7.8
S Of Tonga
11 Oct 1975 · 113 km away
- 1982M7.7
Tonga Trench
19 Dec 1982 · 0 km away
tsunami
- 1963M7.5
Tonga Trench
18 Dec 1963 · 105 km away
tsunami
- 1977M7.2
Tonga Trench
10 Oct 1977 · 197 km away
tsunami
- 1956M7.0
Tonga Islands
10 Jan 1956 · 217 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.