Magnitude5.8

Reviewed by USGSNew Zealand59y ago

M5.8 earthquake 38 km ESE of Westport, New Zealand

Friday, May 24, 1968, 20:57:26 UTC · 41.939°S, 171.999°E

A magnitude 5.8 earthquake struck 38 km ESE of Westport, New Zealand on Friday, May 24, 1968, 20:57:26 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on May 23, 1968.

Magnitude
5.8
Moderate · mw
Depth
15 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
VI
Strong (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

6 kilotons of TNT

That is about 1/2 of the Hiroshima bomb. It released about 13 times the energy of a magnitude 5.0.

Tectonic setting

70 km

from the nearest mapped plate boundary, between the Australian and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

15 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 17 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, which together caused about 23 recorded deaths. The most severe:

  1. 1929M7.5

    South Island

    16 Jun 1929 · 30 km away

    17 deathsModerate damage ($1–5M)tsunami

  2. 1968M7.1

    South Island: Nw Coast

    23 May 1968 · 27 km away

    3 deaths$3 million damage

  3. 1848M6.0

    Awatere River, Marlborough

    18 Oct 1848 · 169 km away

    3 deathstsunami

  4. 1855M8.0

    Wellington,Waiouru,Wanganui,Otaki

    23 Jan 1855 · 261 km away

    Severe damage ($5–24M)tsunami

  5. 1848M7.9

    N.

    15 Oct 1848 · 220 km away

    Limited damage (under $1M)tsunami

  6. 1913M6.8

    Tasman Sea

    22 Feb 1913 · 44 km away · intensity VIII

    Limited damage (under $1M)tsunami

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

Nearby trackers

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