Magnitude4.3

Reviewed by USGSNew Zealand25y ago

M4.3 earthquake in Kermadec Islands, New Zealand

Monday, August 6, 2001, 15:07:48 UTC · 30.313°S, 177.978°W

A magnitude 4.3 earthquake struck in Kermadec Islands, New Zealand on Monday, August 6, 2001, 15:07:48 UTC, at a depth of 250.0 km (intermediate).

Magnitude
4.3
Light · mb
Depth
250 km
Intermediate
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

43 tons of TNT

That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.

Tectonic setting

116 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: intermediate

250 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.6 on August 9, 2001. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M4.3
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.6Kermadec Islands, New Zealand25y ago · 13 km SW of this epicenter
  2. 5.6Kermadec Islands, New Zealand25y ago · 39 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,339 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 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1986M8.1

    Raoul

    20 Oct 1986 · 290 km away

    Limited damage (under $1M)tsunami

  2. 1976M7.9

    Kermadec Islands

    14 Jan 1976 · 135 km away

    Limited damage (under $1M)tsunami

  3. 1968M7.3

    S Of, Raoul

    25 Jul 1968 · 68 km away

    Limited damage (under $1M)tsunami

  4. 1917M8.0

    Kermadec Islands

    1 May 1917 · 156 km away

    tsunami

  5. 1976M7.8

    Kermadec Islands

    14 Jan 1976 · 85 km away · intensity VIII

  6. 1959M7.7

    Kermadec Islands

    14 Sep 1959 · 223 km away

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

Nearby trackers

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