Magnitude4.3

Reviewed by USGSTonga40y ago

M4.3 earthquake 149 km WSW of Haveluloto, Tonga

Sunday, November 9, 1986, 02:03:34 UTC · 21.615°S, 176.565°W

A magnitude 4.3 earthquake struck 149 km WSW of Haveluloto, Tonga on Sunday, November 9, 1986, 02:03:34 UTC, at a depth of 152.4 km (intermediate).

Magnitude
4.3
Light · mb
Depth
152 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 earthquake

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

11 km

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

Depth: intermediate

152 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 879 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, which together caused about 1 recorded deaths. The most severe:

  1. 1977M7.2

    Tonga Trench

    22 Jun 1977 · 156 km away · intensity IV

    1 death$1 million damagetsunami

  2. 1937M8.1

    Fiji Islands

    16 Apr 1937 · 47 km away

  3. 1903M8.0

    Tonga Islands

    4 Jan 1903 · 242 km away

  4. 1948M7.9

    Tonga Islands

    8 Sep 1948 · 274 km away

    tsunami

  5. 1919M7.8

    Fiji Islands

    1 Jan 1919 · 300 km away

    tsunami

  6. 1950M7.7

    Tonga Islands

    14 Dec 1950 · 242 km away · intensity VI

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

Nearby trackers

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