Reviewed by USGS40y ago
M4.8 earthquake south of the Kermadec Islands
Wednesday, February 18, 1987, 01:09:41 UTC · 33.394°S, 178.606°W
A magnitude 4.8 earthquake struck south of the Kermadec Islands on Wednesday, February 18, 1987, 01:09:41 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M5.2 on February 17, 1987.
- Magnitude
- 4.8
- 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 earthquake
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
59 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
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 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 453 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 292 km N of this epicenter
- 7.0Kermadec Islands, New ZealandMay 20, 1968 · 291 km N of this epicenter
- 6.9Kermadec Islands, New ZealandMay 20, 1968 · 297 km N of this epicenter
- 6.9south of the Kermadec IslandsSeptember 26, 1985 · 145 km S of this epicenter
- 6.9south of the Kermadec IslandsJuly 11, 1943 · 100 km NE of this epicenter
- 6.8south of the Kermadec IslandsFebruary 17, 1987 · 93 km NW of this epicenter
- 6.8south of the Kermadec IslandsJanuary 8, 1970 · 290 km SW of this epicenter
- 6.7south of the Kermadec IslandsFebruary 13, 1949 · 82 km E 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:
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 289 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.