M5.3 earthquake 158 km WNW of Malango, Solomon Islands

Tuesday, October 15, 1991, 09:07:17 UTC · 9.131°S, 158.395°E

A magnitude 5.3 earthquake struck 158 km WNW of Malango, Solomon Islands on Tuesday, October 15, 1991, 09:07:17 UTC, at a depth of 25.7 km (shallow). It is the strongest earthquake within 300 km since an M6.1 on October 14, 1991.

Magnitude: 5.3; Moderate · mw
Depth: 26 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

1 kilotons of TNT

That is about 1/11 of the Hiroshima bomb. It released about 3 times the energy of a magnitude 5.0.

Tectonic setting

31 km

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

Depth: shallow

26 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 5 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.6 on November 13, 1991. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 293 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 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 64 recorded deaths. The most severe:

1977M6.8
Solomon Islands
20 Apr 1977 · 225 km away · intensity VI
34 deathsSevere damage ($5–24M)tsunami
1977M8.1
Solomon Islands
21 Apr 1977 · 272 km away · intensity VII
18 deathsSevere damage ($5–24M)tsunami
1939M7.9
Solomon Islands
30 Apr 1939 · 94 km away
12 deathsModerate damage ($1–5M)tsunami
1984M7.5
Guadalcanal
7 Feb 1984 · 248 km away · intensity VI
Moderate damage ($1–5M)
1926M6.9
Solomon Islands
16 Sep 1926 · 137 km away
Moderate damage ($1–5M)tsunami
1977M7.6
Solomon Islands
20 Apr 1977 · 230 km away · intensity VII
Limited damage (under $1M)tsunami

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

Nearby trackers