Reviewed by USGSSolomon Islands38y ago
M4.7 earthquake 114 km W of Kirakira, Solomon Islands
Tuesday, September 20, 1988, 12:56:13 UTC · 10.257°S, 160.894°E
A magnitude 4.7 earthquake struck 114 km W of Kirakira, Solomon Islands on Tuesday, September 20, 1988, 12:56:13 UTC, at a depth of 74.4 km (intermediate). It is the strongest earthquake within 300 km since an M4.7 on September 11, 1988.
- Magnitude
- 4.7
- Light · mb
- Depth
- 74 km
- Intermediate
- 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
59 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: intermediate
74 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 416 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 · 65 km NE of this epicenter
- 7.823 km SSE of Malango, Solomon IslandsApril 30, 1939 · 124 km W of this epicenter
- 7.8108 km SW of Kirakira, Solomon IslandsOctober 3, 1931 · 101 km S of this epicenter
- 7.656 km W of Kirakira, Solomon IslandsDecember 15, 1935 · 58 km E of this epicenter
- 7.6121 km W of Kirakira, Solomon IslandsAugust 10, 1988 · 15 km SW of this epicenter
- 7.685 km SE of Honiara, Solomon IslandsFebruary 7, 1984 · 54 km NW of this epicenter
- 7.5105 km ESE of Honiara, Solomon IslandsApril 20, 1977 · 47 km N of this epicenter
- 7.566 km SE of Honiara, Solomon IslandsApril 20, 1977 · 72 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 115 recorded deaths. The most severe:
- 1931M7.8
San Cristobal Island
3 Oct 1931 · 76 km away
50 deathsSevere damage ($5–24M)tsunami
- 1977M6.8
Solomon Islands
20 Apr 1977 · 79 km away · intensity VI
34 deathsSevere damage ($5–24M)tsunami
- 1977M8.1
Solomon Islands
21 Apr 1977 · 37 km away · intensity VII
18 deathsSevere damage ($5–24M)tsunami
- 1939M7.9
Solomon Islands
30 Apr 1939 · 211 km away
12 deathsModerate damage ($1–5M)tsunami
- 1988M7.6
San Cristobal, Guadalcanal
10 Aug 1988 · 0 km away
1 deathLimited damage (under $1M)tsunami
- 1984M7.5
Guadalcanal
7 Feb 1984 · 54 km away · intensity VI
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.