Reviewed by USGSPapua New Guinea109y ago
M6.7 earthquake 112 km S of Panguna, Papua New Guinea
Sunday, July 21, 1918, 06:09:45 UTC · 7.337°S, 155.525°E
A magnitude 6.7 earthquake struck 112 km S of Panguna, Papua New Guinea on Sunday, July 21, 1918, 06:09:45 UTC, at a depth of 20.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 6.7
- Strong · mw
- Depth
- 20 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: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
163 kilotons of TNT
That is about 11 times the Hiroshima bomb. It released about 343 times the energy of a magnitude 5.0.
Tectonic setting
19 km
from the nearest mapped plate boundary, between the Pacific and Solomon Sea plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
20 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 100 km
USGS lists 1 M2.5+ earthquake within 100 km in the following 30 days; the largest was M6.0 on July 21, 1918. 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 5 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.5177 km SW of Panguna, Papua New GuineaSeptember 3, 1916 · 149 km W of this epicenter
- 6.339 km N of Gizo, Solomon IslandsJune 16, 1918 · 147 km E of this epicenter
- 6.3256 km SSE of Kokopo, Papua New GuineaMay 21, 1913 · 283 km W of this epicenter
- 6.1128 km S of Panguna, Papua New GuineaJuly 12, 1917 · 28 km SW of this epicenter
- 6.0208 km SSE of Kokopo, Papua New GuineaJanuary 4, 1918 · 295 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 1 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1907M7.7
New Britain
4 May 1907 · 202 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.