Reviewed by USGSSolomon Islands50y ago
M4.8 earthquake 30 km NW of Kirakira, Solomon Islands
Wednesday, May 18, 1977, 03:05:41 UTC · 10.240°S, 161.749°E
A magnitude 4.8 earthquake struck 30 km NW of Kirakira, Solomon Islands on Wednesday, May 18, 1977, 03:05:41 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.0 on May 16, 1977.
- Magnitude
- 4.8
- 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
115 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 lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.5 on May 26, 1977. 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 237 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 · 86 km NW of this epicenter
- 7.823 km SSE of Malango, Solomon IslandsApril 30, 1939 · 214 km W of this epicenter
- 7.8108 km SW of Kirakira, Solomon IslandsOctober 3, 1931 · 115 km SW of this epicenter
- 7.656 km W of Kirakira, Solomon IslandsDecember 15, 1935 · 40 km W of this epicenter
- 7.5105 km ESE of Honiara, Solomon IslandsApril 20, 1977 · 111 km NW of this epicenter
- 7.566 km SE of Honiara, Solomon IslandsApril 20, 1977 · 158 km W of this epicenter
- 7.5103 km SE of Honiara, Solomon IslandsApril 21, 1977 · 116 km W of this epicenter
- 7.562 km SW of Malango, Solomon IslandsJanuary 25, 1926 · 271 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 114 recorded deaths. The most severe:
- 1931M7.8
San Cristobal Island
3 Oct 1931 · 111 km away
50 deathsSevere damage ($5–24M)tsunami
- 1977M6.8
Solomon Islands
20 Apr 1977 · 163 km away · intensity VI
34 deathsSevere damage ($5–24M)tsunami
- 1977M8.1
Solomon Islands
21 Apr 1977 · 116 km away · intensity VII
18 deathsSevere damage ($5–24M)tsunami
- 1939M7.9
Solomon Islands
30 Apr 1939 · 295 km away
12 deathsModerate damage ($1–5M)tsunami
- 1926M6.9
Solomon Islands
16 Sep 1926 · 252 km away
Moderate damage ($1–5M)tsunami
- 1977M7.6
Solomon Islands
20 Apr 1977 · 158 km away · intensity VII
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.