Reviewed by USGSSolomon Islands35y ago
M4.7 earthquake 87 km NW of Buala, Solomon Islands
Tuesday, October 29, 1991, 18:18:45 UTC · 7.700°S, 158.941°E
A magnitude 4.7 earthquake struck 87 km NW of Buala, Solomon Islands on Tuesday, October 29, 1991, 18:18:45 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.3 on October 15, 1991.
- Magnitude
- 4.7
- Light · mb
- Depth
- 33 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 earthquake
In context
How big was it, and why here?
Energy released
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
197 km
from the nearest mapped plate boundary, between the Pacific and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
33 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 219 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.823 km SSE of Malango, Solomon IslandsApril 30, 1939 · 261 km S of this epicenter
- 7.566 km SE of Honiara, Solomon IslandsApril 20, 1977 · 288 km SE of this epicenter
- 7.562 km SW of Malango, Solomon IslandsJanuary 25, 1926 · 265 km S of this epicenter
- 7.341 km ESE of Malango, Solomon IslandsFebruary 19, 1906 · 273 km SE of this epicenter
- 7.361 km NW of Gizo, Solomon IslandsApril 19, 1936 · 268 km W of this epicenter
- 7.358 km SSE of Malango, Solomon IslandsAugust 18, 1968 · 297 km S of this epicenter
- 7.2155 km WNW of Malango, Solomon IslandsOctober 14, 1991 · 164 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 46 recorded deaths. The most severe:
- 1977M6.8
Solomon Islands
20 Apr 1977 · 281 km away · intensity VI
34 deathsSevere damage ($5–24M)tsunami
- 1939M7.9
Solomon Islands
30 Apr 1939 · 180 km away
12 deathsModerate damage ($1–5M)tsunami
- 1926M6.9
Solomon Islands
16 Sep 1926 · 229 km away
Moderate damage ($1–5M)tsunami
- 1977M7.6
Solomon Islands
20 Apr 1977 · 288 km away · intensity VII
Limited damage (under $1M)tsunami
- 1926M7.5
Guadalcanal
25 Jan 1926 · 264 km away
Limited damage (under $1M)tsunami
- 1969M7.5
Santa Isabel Island
5 Jan 1969 · 23 km away
Limited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.