Magnitude 1.3, Thu Aug 21 2025 6:28 AM


Download Event Information


Origin


PublicID 2025p626404
UTC Time 2025-08-20T18:28:04Z
Latitude -38.54 (± 6.7 km)
Longitude 175.94 (± 8.1 km)
Depth 105 km (± 15 km)
Depth Type free
Earth Model iasp91
Used Phase Count 13
Used Station Count 9
Standard Error 0.57 (s)
Azimuthal Gap 119.39 (degrees)
Minimum Distance 0.38 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (MLv) 1.3 (± 0.5)  
MLv 1.3 (± 0.5) 3
M 1.3 3

GeoNet combines magnitudes into a summary magnitude, M, which consists of a weighted average of the individual magnitudes and attempts to be a best possible compromise between all magnitudes for a range of earthquake sizes. Summary magnitude for GeoNet is then defined as:

M = (2 * MLv + (0.4 * number_of stations(Mw(mB)) - 1) * Mw(mB)) / (2 + (0.4 * number_of_stations(Mw(mB)) - 1))

Where MLv is local magnitude calculated on the vertical component and Mw(mB) is a Mw estimation based of mB by Bormann and Saul (2008).

Origin Map


Map of New Zealand.

Map showing stations with picks used to locate the earthquake. Stations with picks that have a zero weight in the solution are shown as small grey circles. Those with a higher weight are shown as larger circles. The quake is shown by the largest circle.

Pick Residuals


-6.0-4.0-2.00.02.04.06.0residual (s)0123Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.0Magnitude12Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (MLv)


-1.00.01.0Residual12Distance (degrees)Magnitude Residuals (MLv)