Strong mag. 6.7 earthquake - South Pacific Ocean, 45 km southwest of Nuku\'alofa, Tongatapu, on Monday, 21 March 1983 at 07:44 (GMT)

Strong mag. 6.7 earthquake - South Pacific Ocean, 45 km southwest of Nuku\'alofa, Tongatapu, on Monday, 21 March 1983 at 07:44 (GMT)

Strong magnitude 6.7 earthquake at 68 km depth

Date & time: 21 Mar 1983 07:44:17 UTC
Magnitude: 6.7
Depth: 68.0 km
Epicenter latitude / longitude: 21.466°S / 175.451°W (South Pacific Ocean, Tonga)
Nearest volcano: Unnamed 21.38°S/175.65°W (23 km / 14 mi)
Nearby towns and cities:
43 km (27 mi) SW of Haveluloto (pop: 3,420) --> See nearby quakes!
45 km (28 mi) SW of Nuku'alofa (pop: 22,400) --> See nearby quakes!
45 km (28 mi) SW of Nuku‘alofa (pop: 22,400) --> See nearby quakes!
54 km (34 mi) SW of Kolonga (pop: 1,100) --> See nearby quakes!
216 km (134 mi) SSW of Pangai (pop: 1,740) --> See nearby quakes!
349 km (217 mi) SSW of Neiafu (pop: 4,320) --> See nearby quakes!
Primary data source: USGS (United States Geological Survey)
Estimated released energy: 7.1 x 1014 joules (197 gigawatt hours, equivalent to 1.7 x 105 tons of TNT or 10.6 atomic bombs!) More info
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Data for the same earthquake reported by different agencies

Info: The more agencies report about the same quake and post similar data, the more confidence you can have in the data. It takes normally up to a few hours until earthquake parameters are calculated with near-optimum precision.
MagnitudeDepthLocationSource
M 6.768 kmTongaUSGS
Note: for quakes of 2012 and earlier, our database often contains only records from USGS.

User reports for this quake

User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.
There are no user reports for this quake yet. If you felt it be the first to report it!
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Aftershocks

More info
Recorded aftershocks, latest first (11 quakes):
  • 16 Sep 1983 07:43 UTC
    | M 5.4 |
    46.7 km (29 mi) depth
    |
    12 km (8 mi) distance
    | USGS | Details
  • 28 Jun 1983 21:55 UTC
    | M 5.1 |
    33 km (20.5 mi) depth
    |
    127 km (79 mi) distance
    | USGS | Details
  • 06 May 1983 11:59 UTC
    | M 5.3 |
    33 km (20.5 mi) depth
    |
    132 km (82 mi) distance
    | USGS | Details
  • 30 Apr 1983 02:51 UTC
    | M 5.8 |
    23 km (14.3 mi) depth
    |
    125 km (78 mi) distance
    | USGS | Details
  • 29 Apr 1983 08:23 UTC
    | M 5.0 |
    223.4 km (138.8 mi) depth
    |
    121 km (75 mi) distance
    | USGS | Details
  • 27 Apr 1983 17:20 UTC
    | M 5.6 |
    21 km (13 mi) depth
    |
    128 km (79 mi) distance
    | USGS | Details
  • 25 Apr 1983 10:29 UTC
    | M 4.4 |
    33 km (20.5 mi) depth
    |
    79 km (49 mi) distance
    | USGS | Details
  • 23 Apr 1983 21:05 UTC
    | M 4.7 |
    51 km (31.7 mi) depth
    |
    33 km (21 mi) distance
    | USGS | Details
  • 14 Apr 1983 10:24 UTC
    | M 5.2 |
    33 km (20.5 mi) depth
    |
    7 km (5 mi) distance
    | USGS | Details
  • 07 Apr 1983 15:38 UTC
    | M 5.5 |
    33 km (20.5 mi) depth
    |
    124 km (77 mi) distance
    | USGS | Details
  • 21 Mar 1983 15:49 UTC
    | M 5.5 |
    63 km (39.1 mi) depth
    |
    21 km (13 mi) distance
    | USGS | Details

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Earlier earthquakes in the same area

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