Reviewed by USGS100y ago
M6.3 earthquake south of the Kermadec Islands
Monday, July 18, 1927, 11:19:46 UTC · 34.169°S, 178.893°W
A magnitude 6.3 earthquake struck south of the Kermadec Islands on Monday, July 18, 1927, 11:19:46 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 6.3
- Strong · mw
- Depth
- 15 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 earthquake
In context
How big was it, and why here?
Energy released
51 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 106 times the energy of a magnitude 5.0.
Tectonic setting
54 km
from the nearest mapped plate boundary, between the Kermadec and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
15 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 4 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.3south of the Kermadec IslandsMay 24, 1917 · 156 km N of this epicenter
- 6.3south of the Kermadec IslandsOctober 1, 1923 · 230 km NE of this epicenter
- 6.0south of the Kermadec IslandsApril 30, 1924 · 271 km NE of this epicenter
- 6.0south of the Kermadec IslandsMay 10, 1924 · 134 km NE of this epicenter