QuakeScout
Magnitude4.3

Reviewed by USGS8y ago

M4.3 earthquake in Kermadec Islands region

Tuesday, September 11, 2018, 23:19:50 UTC · 31.733°S, 179.281°W

A magnitude 4.3 earthquake struck in Kermadec Islands region on Tuesday, September 11, 2018, 23:19:50 UTC, at a depth of 120.3 km (intermediate).

Magnitude
4.3
Light · mb
Depth
120 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

39 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: intermediate

120 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 M4.5 on September 24, 2018. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M41h6h1d3d7d14d30dMainshock M4.3
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.4Kermadec Islands region8y ago · 22 km SE of this epicenter
  2. 4.5south of the Kermadec Islands8y ago · 34 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,842 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.21917 Kermadec Islands, New Zealand EarthquakeMay 1, 1917 · 256 km E of this epicenter
  2. 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 251 km NE of this epicenter
  3. 7.4Kermadec Islands regionMay 16, 2006 · 9 km S of this epicenter
  4. 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 247 km NE of this epicenter
  5. 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 150 km NE of this epicenter
  6. 7.2Kermadec Islands, New ZealandFebruary 9, 1978 · 217 km NE of this epicenter
  7. 7.2Kermadec Islands, New ZealandJune 3, 2001 · 238 km N of this epicenter
  8. 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 270 km NE of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1968M7.3

    S Of, Raoul

    25 Jul 1968 · 133 km away

    Limited damage (under $1M)tsunami

  2. 1976M7.8

    Kermadec Islands

    14 Jan 1976 · 281 km away · intensity VIII

  3. 1978M7.7

    S Of

    9 Feb 1978 · 217 km away

  4. 1943M7.6

    S Of

    14 Sep 1943 · 291 km away

  5. 2014M6.9

    Sse Of Raoul Island

    23 Jun 2014 · 245 km away

    tsunami

  6. 2013M6.5

    S Of, Raoul

    30 Sep 2013 · 128 km away

    tsunami

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

Nearby trackers

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