Magnitude4.1

Reviewed by USGS7y ago

M4.1 earthquake in Fiji region

Friday, October 11, 2019, 19:48:44 UTC · 20.696°S, 178.161°W

A magnitude 4.1 earthquake struck in Fiji region on Friday, October 11, 2019, 19:48:44 UTC, at a depth of 508.0 km (deep).

Magnitude
4.1
Light · mb
Depth
508 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

21 tons of TNT

That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.

Tectonic setting

197 km

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

Depth: deep

508 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.2 on November 6, 2019. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M41h6h1d3d7d14d30dMainshock M4.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.2Fiji region6y ago · 27 km W of this epicenter
  2. 4.1285 km WNW of Haveluloto, Tonga6y ago · 36 km NE of this epicenter
  3. 4.2268 km W of Haveluloto, Tonga7y ago · 45 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,604 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 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 2018M8.2

    Fiji Islands

    19 Aug 2018 · 287 km away · intensity V

    tsunami

  2. 1937M8.1

    Fiji Islands

    16 Apr 1937 · 150 km away

  3. 1919M7.8

    Fiji Islands

    1 Jan 1919 · 153 km away

    tsunami

  4. 1950M7.7

    Tonga Islands

    14 Dec 1950 · 262 km away · intensity VI

  5. 1997M7.7

    Tonga Islands

    14 Oct 1997 · 212 km away

    tsunami

  6. 2002M7.7

    Fiji Islands

    19 Aug 2002 · 179 km away

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

Nearby trackers

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