Reviewed by USGSNew Zealand22y ago
M3.8 earthquake 220 km W of Riverton, New Zealand
Monday, November 22, 2004, 22:21:46 UTC · 46.570°S, 165.170°E
A magnitude 3.8 earthquake struck 220 km W of Riverton, New Zealand on Monday, November 22, 2004, 22:21:46 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 3.8
- Minor · ml
- 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 earthquake
In context
How big was it, and why here?
Energy released
8 tons of TNT
That is about 1/1,992 of the Hiroshima bomb. A magnitude 5.0 releases about 63 times more energy.
Tectonic setting
8 km
from the nearest mapped plate boundary, between the Pacific 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 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 79 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6off the west coast of the South Island of New ZealandMay 25, 1981 · 254 km S of this epicenter
- 7.5173 km WSW of Riverton, New ZealandSeptember 1, 1945 · 76 km SE of this epicenter
- 7.4180 km W of Riverton, New ZealandOctober 12, 1979 · 43 km E of this epicenter
- 7.256 km NW of Te Anau, New ZealandAugust 21, 2003 · 224 km NE of this epicenter
- 7.1255 km W of Riverton, New ZealandNovember 22, 2004 · 36 km W of this epicenter
- 7.0Auckland Islands, New Zealand regionSeptember 12, 1964 · 279 km S of this epicenter
- 7.063 km WNW of Te Anau, New ZealandAugust 10, 1993 · 198 km NE of this epicenter
- 7.015 km WNW of Te Anau, New ZealandDecember 16, 1938 · 226 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 2003M7.2
Dunedin,Invercargill,Te Anau,Fiordland
21 Aug 2003 · 224 km away
Limited damage (under $1M)tsunami
- 2004M7.1
Invercargill, Southland, Otago
22 Nov 2004 · 36 km away
Limited damage (under $1M)tsunami
- 1826M8.0
Fjordland
1826 · 133 km away
- 1981M7.6
W Of North Island
25 May 1981 · 254 km away
tsunami
- 1979M7.5
W Of North Island
12 Oct 1979 · 43 km away · intensity V
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.