Reviewed by USGS29y ago
M5.0 earthquake south of the Kermadec Islands
Saturday, June 21, 1997, 19:34:48 UTC · 32.875°S, 179.200°W
A magnitude 5.0 earthquake struck south of the Kermadec Islands on Saturday, June 21, 1997, 19:34:48 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.1 on June 19, 1997.
- Magnitude
- 5.0
- Moderate · mb
- Depth
- 33 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
477 tons of TNT
That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.
Tectonic setting
93 km
from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
33 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 75 km
USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M4.4 on July 10, 1997. 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 811 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 · 251 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandFebruary 9, 1978 · 300 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandApril 17, 1919 · 280 km NE of this epicenter
- 7.1Kermadec Islands, New ZealandJune 29, 1910 · 295 km NE of this epicenter
- 7.1Kermadec Islands, New ZealandSeptember 26, 1968 · 274 km NE of this epicenter
- 7.1south of the Kermadec IslandsMay 25, 1997 · 127 km NW of this epicenter
- 7.0Kermadec Islands, New ZealandMay 20, 1968 · 250 km NE of this epicenter
- 7.0Kermadec Islands, New ZealandMay 14, 1989 · 272 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 2 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 · 243 km away
Limited damage (under $1M)tsunami
- 1978M7.7
S Of
9 Feb 1978 · 300 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.