Magnitude 4.8, Wed Apr 30 2025 1:15 PM


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Origin


PublicID 2025p321767
UTC Time 2025-04-30T01:15:23Z
Latitude -25.70 (± 7.2 km)
Longitude -179.71 (± 65.1 km)
Depth 500 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 10
Used Station Count 8
Standard Error 1.34 (s)
Azimuthal Gap 202.22 (degrees)
Minimum Distance 8.19 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (mB) 4.8 (± 0.4)  
mB 4.8 (± 0.4) 2
Mw(mB) 4.1 (± 0.4) 2

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


-3.0-2.0-1.00.01.02.03.0residual (s)02468101214Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.06.0Magnitude13Distance (degrees)Station Magnitudes (mB)

Magnitude Residuals (mB)


-1.00.01.0Residual13Distance (degrees)Magnitude Residuals (mB)