Magnitude4.2

Reviewed by USGS21y ago

M4.2 earthquake in Fiji region

Tuesday, March 15, 2005, 08:38:58 UTC · 19.424°S, 177.438°W

A magnitude 4.2 earthquake struck in Fiji region on Tuesday, March 15, 2005, 08:38:58 UTC, at a depth of 548.6 km (deep).

Magnitude
4.2
Light · mb
Depth
549 km
Deep
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

30 tons of TNT

That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.

Tectonic setting

96 km

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

Depth: deep

549 km

Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.

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 M4.7 on April 11, 2005. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M4.2
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.7Fiji region21y ago · 25 km NW of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,408 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. 1937M8.1

    Fiji Islands

    16 Apr 1937 · 235 km away

  2. 1903M8.0

    Tonga Islands

    4 Jan 1903 · 263 km away

  3. 1909M7.8

    Fiji Islands

    22 Feb 1909 · 228 km away

  4. 1919M7.8

    Fiji Islands

    1 Jan 1919 · 68 km away

    tsunami

  5. 1950M7.7

    Tonga Islands

    14 Dec 1950 · 151 km away · intensity VI

  6. 1994M7.6

    Fiji Islands

    9 Mar 1994 · 185 km away

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

Nearby trackers

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