Magnitude4.9

Reviewed by USGSIndonesia36y ago

M4.9 earthquake 98 km NNE of Gorontalo, Indonesia

Monday, August 13, 1990, 16:12:33 UTC · 1.371°N, 123.377°E

A magnitude 4.9 earthquake struck 98 km NNE of Gorontalo, Indonesia on Monday, August 13, 1990, 16:12:33 UTC, at a depth of 37.4 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on August 10, 1990.

Magnitude
4.9
Light · mb
Depth
37 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 earthquakeDashed circle: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

338 tons of TNT

That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.

Tectonic setting

16 km

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

Depth: shallow

37 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 50 km

USGS lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.7 on September 9, 1990. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M4.9
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.765 km N of Gorontalo, Indonesia36y ago · 49 km SW of this epicenter
  2. 5.094 km NNE of Gorontalo, Indonesia36y ago · 11 km SE of this epicenter
  3. 5.170 km NE of Gorontalo, Indonesia36y ago · 35 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 561 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 21 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 130 recorded deaths. The most severe:

  1. 1845M7.0

    N Sulawesi: Menado, Tikala, Tomohon

    8 Feb 1845 · 164 km away · intensity IX

    118 deathsModerate damage ($1–5M)tsunami

  2. 1932M7.7

    Sulawesi: Kakas,Langowan,Poso,Tondano

    14 May 1932 · 299 km away · intensity VII

    7 deathsSevere damage ($5–24M)tsunami

  3. 1990M7.6

    Minahassa Peninsula: Bolaang-Gorontalo

    18 Apr 1990 · 61 km away

    3 deathsSevere damage ($5–24M)

  4. 1983M6.1

    Central Sulawesi

    25 Oct 1983 · 281 km away · intensity VII

    2 deathsModerate damage ($1–5M)

  5. 1858M7.3

    N. Moluccas Islands

    13 Dec 1858 · 295 km away

    Severe damage ($5–24M)tsunami

  6. 1939M8.0

    Centrtal Sulawesi: Kalo,Luwuk,Sula I

    21 Dec 1939 · 158 km away

    Moderate damage ($1–5M)tsunami

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

Nearby trackers

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