Magnitude5.5

Reviewed by USGSIndonesia25y ago

M5.5 earthquake 157 km ENE of Katabu, Indonesia

Saturday, October 20, 2001, 19:17:52 UTC · 4.561°S, 123.885°E

A magnitude 5.5 earthquake struck 157 km ENE of Katabu, Indonesia on Saturday, October 20, 2001, 19:17:52 UTC, at a depth of 28.7 km (shallow). It is the strongest earthquake within 300 km since an M7.5 on October 19, 2001.

Magnitude
5.5
Moderate · mwc
Depth
29 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: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

3 kilotons of TNT

That is about 1/6 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.

Tectonic setting

11 km

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

Depth: shallow

29 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 75 km

USGS lists 4 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.7 on October 21, 2001. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 124 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 2 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 41 recorded deaths. The most severe:

  1. 1998M7.7

    Mangole, Manado, Taliabu

    29 Nov 1998 · 299 km away · intensity VII

    41 deaths$200 million damagetsunami

  2. 2001M7.5

    Banda Sea

    19 Oct 2001 · 51 km away

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

Nearby trackers

Closest city pages