Magnitude5.5

Reviewed by USGSNew Zealand49y ago

M5.5 earthquake in Kermadec Islands, New Zealand

Sunday, March 12, 1978, 16:13:13 UTC · 30.677°S, 178.137°W

A magnitude 5.5 earthquake struck in Kermadec Islands, New Zealand on Sunday, March 12, 1978, 16:13:13 UTC, at a depth of 37.0 km (shallow). It is the strongest earthquake within 300 km since an M5.7 on February 11, 1978.

Magnitude
5.5
Moderate · mb
Depth
37 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

3 kilotons of TNT

That is about 1/6 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.

Tectonic setting

110 km

from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

37 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 has not published any M2.5+ earthquake within 75 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 481 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1976M7.9

    Kermadec Islands

    14 Jan 1976 · 178 km away

    Limited damage (under $1M)tsunami

  2. 1968M7.3

    S Of, Raoul

    25 Jul 1968 · 29 km away

    Limited damage (under $1M)tsunami

  3. 1917M8.0

    Kermadec Islands

    1 May 1917 · 197 km away

    tsunami

  4. 1976M7.8

    Kermadec Islands

    14 Jan 1976 · 121 km away · intensity VIII

  5. 1959M7.7

    Kermadec Islands

    14 Sep 1959 · 266 km away

  6. 1978M7.7

    S Of

    9 Feb 1978 · 74 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

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