Reviewed by USGSNew Zealand42y ago
M4.8 earthquake 174 km NNE of Opotiki, New Zealand
Sunday, January 13, 1985, 18:05:06 UTC · 36.498°S, 177.810°E
A magnitude 4.8 earthquake struck 174 km NNE of Opotiki, New Zealand on Sunday, January 13, 1985, 18:05:06 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on January 13, 1985.
- Magnitude
- 4.8
- 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
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
25 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 50 km
USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.8 on January 14, 1985. 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 125 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.746 km E of Gisborne, New ZealandMarch 25, 1947 · 250 km S of this epicenter
- 7.682 km ENE of Gisborne, New ZealandMay 17, 1947 · 237 km SE of this epicenter
- 7.044 km N of Whakatane, New ZealandNovember 22, 1914 · 143 km SW of this epicenter
- 6.8150 km N of Opotiki, New ZealandDecember 30, 1984 · 32 km SW of this epicenter
- 6.8south of the Kermadec IslandsJanuary 8, 1970 · 203 km NE of this epicenter
- 6.748 km ENE of Opotiki, New ZealandOctober 6, 1914 · 158 km S of this epicenter
- 6.6off the east coast of the North Island of New ZealandFebruary 13, 1938 · 162 km E of this epicenter
- 6.4east of the North Island of New ZealandSeptember 22, 1930 · 236 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1 recorded deaths. The most severe:
- 1914
North Island
6 Oct 1914 · 149 km away · intensity VIII
1 deathModerate damage ($1–5M)tsunami
- 1932M6.8
Gisborne, Wairoa
15 Sep 1932 · 280 km away
Moderate damage ($1–5M)tsunami
- 1947M7.1
Off Coast North Island
25 Mar 1947 · 278 km away · intensity IV
Limited damage (under $1M)tsunami
- 1880M7.0
Gisborne
8 Sep 1880 · 277 km away
tsunami
- 1947M6.9
Off Coast North Island
17 May 1947 · 234 km away
tsunami
- 1950M5.8
N. New Zealand
14 Mar 1950 · 155 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.