QQuakeFacts
USGS iscgemsup16958157

21 Aug 1911, 16:28

241 km WNW of Houma, Tonga

A magnitude 7.2 mB earthquake at 230 km depth.

Depth230 kmPublished hypocentral depth
Tsunami flagNot flaggedUSGS catalog flag, not a current warning
Updated22 August 2025Latest timestamp stored in this record

Published location

Where is 241 km WNW of Houma, Tonga?

This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.

-20.004000, -177.265000

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What the numbers mean

Magnitude measures event size; depth locates the source below the surface. Neither value alone establishes local damage or personal risk.

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Catalog fields and provenance
Event ID
iscgemsup16958157
Coordinates
-20.004, -177.265
Network
iscgemsup
Significance
798