Very strong mag. 6.4 earthquake - 57 km north of Sibolga, North Sumatra, Indonesia, on Saturday, 25 April 1987 at 19:22 (GMT)

Very strong mag. 6.4 earthquake - 57 km north of Sibolga, North Sumatra, Indonesia, on Saturday, 25 April 1987 at 19:22 (GMT)

Very strong magnitude 6.4 earthquake at 11 km depth

1 Jan 00:00 UTC: First to report: USGS after 30 seconds.
Date & time: 25 Apr 1987 19:22:07 UTC
Magnitude: 6.4
Depth: 11.1 km
Epicenter latitude / longitude: 2.244°N / 98.866°E (North Sumatra, Indonesia)
Nearest volcano: Toba (11 km / 7 mi)
Nearby towns and cities:
45 km (28 mi) S of Tomok Bolon (Kabupaten Samosir, North Sumatra) (pop: 10,000) --> See nearby quakes!
47 km (29 mi) S of Parapat (Kabupaten Simalungun, North Sumatra) (pop: 10,000) --> See nearby quakes!
57 km (35 mi) N of Sibolga (North Sumatra) (pop: 79,700) --> See nearby quakes!
82 km (51 mi) SSE of Tongging (Kabupaten Karo, North Sumatra) (pop: 16,000) --> See nearby quakes!
83 km (51 mi) SSW of Pematangsiantar (North Sumatra) (pop: 209,600) --> See nearby quakes!
106 km (66 mi) NNW of Padangsidempuan (North Sumatra) (pop: 100,600) --> See nearby quakes!
109 km (68 mi) W of Rantauprapat (North Sumatra) (pop: 103,000) --> See nearby quakes!
151 km (94 mi) S of Medan (North Sumatra) (pop: 1,751,000) --> See nearby quakes!
329 km (204 mi) WSW of Kuala Lumpur (Malaysia) (pop: 1,454,000) --> See nearby quakes!
392 km (243 mi) NNW of Padang (West Sumatra) (pop: 840,400) --> See nearby quakes!
Primary data source: USGS (United States Geological Survey)
Estimated released energy: 2.5 x 1014 joules (69.8 gigawatt hours, equivalent to 60036 tons of TNT or 3.8 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.
Mag.DepthLocationSource
6.411 kmnorthern Sumatra, IndonesiaUSGS
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 (10 quakes):
  • 22 Oct 1987 15:49 UTC
    | M 4.4 |
    162.2 km (100.8 mi) depth
    |
    26 km (16 mi) distance
    | USGS | Details
  • 21 Sep 1987 18:21 UTC
    | M 4.5 |
    182.7 km (113.5 mi) depth
    |
    83 km (52 mi) distance
    | USGS | Details
  • 15 Jun 1987 16:24 UTC
    | M 4.0 |
    130 km (80.8 mi) depth
    |
    71 km (44 mi) distance
    | USGS | Details
  • 28 May 1987 08:01 UTC
    | M 3.9 |
    94.9 km (59 mi) depth
    |
    66 km (41 mi) distance
    | USGS | Details
  • 30 Apr 1987 21:20 UTC
    | M 4.7 |
    43.1 km (26.8 mi) depth
    |
    24 km (15 mi) distance
    | USGS | Details
  • 29 Apr 1987 21:41 UTC
    | M 4.5 |
    177.4 km (110.2 mi) depth
    |
    77 km (48 mi) distance
    | USGS | Details
  • 29 Apr 1987 17:18 UTC
    | M 3.8 |
    73.4 km (45.6 mi) depth
    |
    18 km (11 mi) distance
    | USGS | Details
  • 29 Apr 1987 07:29 UTC
    | M 4.1 |
    65.4 km (40.6 mi) depth
    |
    35 km (22 mi) distance
    | USGS | Details
  • 28 Apr 1987 22:44 UTC
    | M 4.9 |
    33 km (20.5 mi) depth
    |
    34 km (21 mi) distance
    | USGS | Details
  • 28 Apr 1987 15:32 UTC
    | M 5.8 |
    19.3 km (12 mi) depth
    |
    32 km (20 mi) distance
    | USGS | Details

Earlier earthquakes in the same area

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