Reviewed by USGSSolomon Islands19y ago
M4.5 earthquake 83 km NW of Gizo, Solomon Islands
Saturday, August 4, 2007, 17:44:58 UTC · 7.589°S, 156.292°E
A magnitude 4.5 earthquake struck 83 km NW of Gizo, Solomon Islands on Saturday, August 4, 2007, 17:44:58 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on August 3, 2007.
- Magnitude
- 4.5
- Light · mb
- Depth
- 10 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
85 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
42 km
from the nearest mapped plate boundary, between the Pacific and Woodlark plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 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 M4.1 on August 26, 2007. 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 1,076 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.12007 Solomon Islands EarthquakeApril 1, 2007 · 128 km SE of this epicenter
- 7.956 km WSW of Panguna, Papua New GuineaJuly 20, 1975 · 176 km NW of this epicenter
- 7.885 km S of Panguna, Papua New GuineaJanuary 30, 1939 · 114 km NW of this epicenter
- 7.794 km SSW of Panguna, Papua New GuineaJuly 20, 1975 · 137 km NW of this epicenter
- 7.361 km NW of Gizo, Solomon IslandsApril 19, 1936 · 25 km E of this epicenter
- 7.2282 km SW of Panguna, Papua New GuineaOctober 23, 1974 · 265 km W of this epicenter
- 7.2143 km W of Gizo, Solomon IslandsJuly 29, 1977 · 97 km SW of this epicenter
- 7.2139 km WNW of Panguna, Papua New GuineaAugust 16, 1995 · 295 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 58 recorded deaths. The most severe:
- 2007M8.1
Solomon Islands
1 Apr 2007 · 128 km away
52 deathsSevere damage ($5–24M)tsunami
- 1939M7.7
Bougainville Island
30 Jan 1939 · 115 km away
5 deathsModerate damage ($1–5M)tsunami
- 1996M7.2
Bougainville Island
29 Apr 1996 · 186 km away
1 deathModerate damage ($1–5M)
- 1975M7.9
Bismarck Sea: Bougainville
20 Jul 1975 · 176 km away · intensity VIII
Severe damage ($5–24M)tsunami
- 1959M7.3
Solomon Islands
17 Aug 1959 · 34 km away
Severe damage ($5–24M)tsunami
- 1974M7.1
Solomon Islands
1 Feb 1974 · 79 km away · intensity VI
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.