QuakeScout
Magnitude6.4

Reviewed by USGSTimor Leste43y ago

M6.4 earthquake 108 km NNE of Lospalos, Timor Leste

Monday, December 12, 1983, 09:26:07 UTC · 7.583°S, 127.288°E

A magnitude 6.4 earthquake struck 108 km NNE of Lospalos, Timor Leste on Monday, December 12, 1983, 09:26:07 UTC, at a depth of 136.9 km (intermediate). It is the strongest earthquake within 300 km since an M7.3 on November 24, 1983.

Magnitude
6.4
Strong · mw
Depth
137 km
Intermediate
Felt reports
0
Did You Feel It?
Est. shaking
V
Moderate (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

60 kilotons of TNT

That is about 4 times the Hiroshima bomb. It released about 126 times the energy of a magnitude 5.0.

Tectonic setting

44 km

from the nearest mapped plate boundary, between the Banda Sea and Timor plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: intermediate

137 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

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 100 km

USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 314 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.11963 Banda Sea EarthquakeNovember 4, 1963 · 265 km E of this epicenter
  2. 7.7Banda SeaNovember 2, 1950 · 225 km E of this epicenter
  3. 7.3145 km NNE of Lospalos, Timor LesteAugust 30, 1917 · 45 km NE of this epicenter
  4. 7.3172 km NE of Lospalos, Timor LesteNovember 24, 1983 · 98 km E of this epicenter
  5. 7.2187 km N of Baukau, Timor LesteFebruary 11, 1969 · 118 km NW of this epicenter
  6. 7.258 km ENE of Lospalos, Timor LesteSeptember 29, 1905 · 80 km S of this epicenter
  7. 7.1186 km NE of Lospalos, Timor LesteMay 15, 1962 · 106 km E of this epicenter
  8. 7.077 km N of Baukau, Timor LesteFebruary 14, 1952 · 90 km W of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 250 recorded deaths. The most severe:

  1. 1896

    Timor: Alor Island

    18 Apr 1896 · 289 km away · intensity VIII

    250 deathsModerate damage ($1–5M)

  2. 1963M8.3

    Banda Sea

    4 Nov 1963 · 265 km away

    Limited damage (under $1M)

  3. 1918M8.1

    Banda Sea

    18 Nov 1918 · 200 km away

  4. 1950M8.1

    Banda Sea

    2 Nov 1950 · 272 km away

  5. 1917M7.8

    Banda Sea

    30 Aug 1917 · 79 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

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