Reviewed by USGSSolomon Islands96y ago
M7.8 earthquake 116 km NW of Kirakira, Solomon Islands
Saturday, October 10, 1931, 00:19:57 UTC · 9.734°S, 161.151°E
A magnitude 7.8 earthquake struck 116 km NW of Kirakira, Solomon Islands on Saturday, October 10, 1931, 00:19:57 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.8
- Major · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
8.7 megatons of TNT
That is about 576 times the Hiroshima bomb. It released about 18,197 times the energy of a magnitude 5.0.
Tectonic setting
123 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
15 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 200 km
USGS lists 5 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.2 on October 23, 1931. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 6.256 km S of Auki, Solomon Islands96y ago · 65 km NW of this epicenter
- 6.258 km SE of Kirakira, Solomon Islands96y ago · 175 km SE of this epicenter
- 6.0146 km N of Kirakira, Solomon Islands96y ago · 125 km NE of this epicenter
- 6.0118 km NW of Kirakira, Solomon Islands96y ago · 14 km SW of this epicenter
- 6.1112 km NW of Kirakira, Solomon Islands96y ago · 22 km NE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 29 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8108 km SW of Kirakira, Solomon IslandsOctober 3, 1931 · 154 km S of this epicenter
- 7.562 km SW of Malango, Solomon IslandsJanuary 25, 1926 · 208 km W of this epicenter
- 7.547 km ESE of Kirakira, Solomon IslandsDecember 10, 1910 · 163 km SE of this epicenter
- 7.334 km WNW of Kirakira, Solomon IslandsApril 12, 1926 · 87 km SE of this epicenter
- 7.341 km ESE of Malango, Solomon IslandsFebruary 19, 1906 · 123 km W of this epicenter
- 7.3128 km SE of Kirakira, Solomon IslandsApril 11, 1914 · 245 km SE of this epicenter
- 7.133 km WNW of Malango, Solomon IslandsSeptember 16, 1926 · 186 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 50 recorded deaths. The most severe:
- 1931M7.8
San Cristobal Island
3 Oct 1931 · 134 km away
50 deathsSevere damage ($5–24M)tsunami
- 1926M6.9
Solomon Islands
16 Sep 1926 · 179 km away
Moderate damage ($1–5M)tsunami
- 1926M7.5
Guadalcanal
25 Jan 1926 · 215 km away
Limited damage (under $1M)tsunami
- 1931M7.7
Solomon Islands
10 Oct 1931 · 26 km away
- 1926M7.5
Solomon Islands
12 Apr 1926 · 34 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.