QuakeScout
Magnitude6.5

Reviewed by USGS121y ago

M6.5 earthquake in Tonga

Tuesday, December 18, 1906, 20:59:15 UTC · 21.719°S, 173.904°W

A magnitude 6.5 earthquake struck in Tonga on Tuesday, December 18, 1906, 20:59:15 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on March 18, 1905.

Magnitude
6.5
Strong · mw
Depth
15 km
Shallow
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

82 kilotons of TNT

That is about 5 times the Hiroshima bomb. It released about 172 times the energy of a magnitude 5.0.

Tectonic setting

2 km

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

Depth: shallow

15 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

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 100 km

USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 4 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.0TongaJanuary 4, 1903 · 222 km NW of this epicenter
  2. 7.4south of TongaMarch 18, 1905 · 299 km S of this epicenter
  3. 6.915 km WSW of Pangai, TongaFebruary 27, 1905 · 214 km N of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1865M8.0

    Tonga Islands

    18 Nov 1865 · 250 km away

    Limited damage (under $1M)tsunami

  2. 1903M8.0

    Tonga Islands

    4 Jan 1903 · 222 km away

  3. 1902M7.8

    Tonga Islands

    9 Feb 1902 · 191 km away

  4. 1853

    Tonga Trench

    24 Dec 1853 · 144 km away

    tsunami

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

Nearby trackers

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