Magnitude5.0

Reviewed by USGSTonga20y ago

M5.0 earthquake 100 km SSE of Pangai, Tonga

Wednesday, June 28, 2006, 13:00:25 UTC · 20.661°S, 174.002°W

A magnitude 5.0 earthquake struck 100 km SSE of Pangai, Tonga on Wednesday, June 28, 2006, 13:00:25 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M5.4 on June 23, 2006.

Magnitude
5.0
Moderate · mwc
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 earthquakeDashed circle: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

477 tons of TNT

That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.

Tectonic setting

53 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 75 km

USGS lists 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.6 on July 5, 2006. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M5.0
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.2113 km SSE of Pangai, Tonga20y ago · 14 km S of this epicenter
  2. 5.6Tonga20y ago · 17 km NW of this epicenter
  3. 4.696 km SSE of Pangai, Tonga20y ago · 5 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,119 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 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1919M8.1

    Tonga Islands

    30 Apr 1919 · 300 km away

    Limited damage (under $1M)tsunami

  2. 1865M8.0

    Tonga Islands

    18 Nov 1865 · 139 km away

    Limited damage (under $1M)tsunami

  3. 2006M7.9

    Tonga Islands

    3 May 2006 · 54 km away · intensity VII

    Limited damage (under $1M)tsunami

  4. 1903M8.0

    Tonga Islands

    4 Jan 1903 · 127 km away

  5. 1948M7.9

    Tonga Islands

    8 Sep 1948 · 38 km away

    tsunami

  6. 1902M7.8

    Tonga Islands

    9 Feb 1902 · 74 km away

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

Nearby trackers

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