M8.0 earthquake in Tonga

Sunday, January 4, 1903, 05:07:00 UTC · 20.000°S, 175.000°W

A magnitude 8.0 earthquake struck in Tonga on Sunday, January 4, 1903, 05:07:00 UTC, at a depth of 400.0 km (deep). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 8.0; Great · mh
Depth: 400 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 earthquake

In context

How big was it, and why here?

Energy released

15 megatons of TNT

That is about 1,002 times the Hiroshima bomb. It released about 31,623 times the energy of a magnitude 5.0.

Tectonic setting

40 km

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

Depth: deep

400 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 400 km

USGS has not published any M2.5+ earthquake within 400 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists no earlier M5.0+ earthquakes within 300 km.

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:

1865M8.0
Tonga Islands
18 Nov 1865 · 167 km away
Limited damage (under $1M)tsunami
1903M8.0
Tonga Islands
4 Jan 1903 · 0 km away
1902M7.8
Tonga Islands
9 Feb 1902 · 104 km away
1853
Tonga Trench
24 Dec 1853 · 131 km away
tsunami

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

Nearby trackers