Reviewed by USGSSolomon Islands58y ago
M7.3 earthquake 58 km SSE of Malango, Solomon Islands
Sunday, August 18, 1968, 18:38:32 UTC · 10.188°S, 159.914°E
A magnitude 7.3 earthquake struck 58 km SSE of Malango, Solomon Islands on Sunday, August 18, 1968, 18:38:32 UTC, at a depth of 543.1 km (deep). It is the strongest earthquake within 300 km since an M7.8 on April 30, 1939.
- Magnitude
- 7.3
- Major · mw
- Depth
- 543 km
- Deep
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- III
- Weak (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
1.2 megatons of TNT
That is about 80 times the Hiroshima bomb. It released about 2,541 times the energy of a magnitude 5.0.
Tectonic setting
10 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: deep
543 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 102 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8116 km NW of Kirakira, Solomon IslandsOctober 10, 1931 · 145 km E of this epicenter
- 7.823 km SSE of Malango, Solomon IslandsApril 30, 1939 · 35 km N of this epicenter
- 7.8108 km SW of Kirakira, Solomon IslandsOctober 3, 1931 · 174 km SE of this epicenter
- 7.656 km W of Kirakira, Solomon IslandsDecember 15, 1935 · 165 km E of this epicenter
- 7.562 km SW of Malango, Solomon IslandsJanuary 25, 1926 · 71 km W of this epicenter
- 7.547 km ESE of Kirakira, Solomon IslandsDecember 10, 1910 · 266 km E of this epicenter
- 7.334 km WNW of Kirakira, Solomon IslandsApril 12, 1926 · 188 km E of this epicenter
- 7.341 km ESE of Malango, Solomon IslandsFebruary 19, 1906 · 35 km NE 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 62 recorded deaths. The most severe:
- 1931M7.8
San Cristobal Island
3 Oct 1931 · 146 km away
50 deathsSevere damage ($5–24M)tsunami
- 1939M7.9
Solomon Islands
30 Apr 1939 · 124 km away
12 deathsModerate damage ($1–5M)tsunami
- 1926M6.9
Solomon Islands
16 Sep 1926 · 72 km away
Moderate damage ($1–5M)tsunami
- 1926M7.5
Guadalcanal
25 Jan 1926 · 78 km away
Limited damage (under $1M)tsunami
- 1931M7.7
Solomon Islands
10 Oct 1931 · 142 km away
- 1935M7.6
Solomon Islands
15 Dec 1935 · 127 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.