Reviewed by USGSNew Zealand33y ago
M4.5 earthquake 85 km W of Te Anau, New Zealand
Tuesday, August 17, 1993, 06:53:06 UTC · 45.473°S, 166.630°E
A magnitude 4.5 earthquake struck 85 km W of Te Anau, New Zealand on Tuesday, August 17, 1993, 06:53:06 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.5 on August 14, 1993.
- Magnitude
- 4.5
- Light · 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
85 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
13 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 lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.4 on August 17, 1993. 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 39 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.5173 km WSW of Riverton, New ZealandSeptember 1, 1945 · 176 km S of this epicenter
- 7.4180 km W of Riverton, New ZealandOctober 12, 1979 · 151 km SW of this epicenter
- 7.015 km WNW of Te Anau, New ZealandDecember 16, 1938 · 71 km E of this epicenter
- 7.063 km WNW of Te Anau, New ZealandAugust 10, 1993 · 32 km NE of this epicenter
- 6.762 km WNW of Te Anau, New ZealandAugust 2, 1943 · 36 km NE of this epicenter
- 6.746 km NNW of Te Anau, New ZealandJune 3, 1988 · 92 km NE of this epicenter
- 6.686 km N of Te Anau, New ZealandMay 4, 1976 · 118 km NE of this epicenter
- 6.6115 km WNW of Te Anau, New ZealandDecember 16, 1938 · 70 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:
- 1826M8.0
Fjordland
1826 · 38 km away
- 1979M7.5
W Of North Island
12 Oct 1979 · 151 km away · intensity V
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.