Magnitude 2.8, Wed May 28 2025 9:06 PM


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Origin


PublicID 2025p398320
UTC Time 2025-05-28T09:06:01Z
Latitude -43.60 (± 76.7 km)
Longitude 171.00 (± 88.0 km)
Depth 217 km (± 105 km)
Depth Type free
Earth Model nz3drx
Used Phase Count 9
Used Station Count 9
Standard Error 2.15 (s)
Azimuthal Gap 85.30 (degrees)
Minimum Distance 0.12 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 2.8  
MLv 2.8 (± 0.0) 2
M 2.8 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


-6.0-4.0-2.00.02.04.06.0residual (s)01Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.0Magnitude1Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (MLv)


-1.00.01.0Residual1Distance (degrees)Magnitude Residuals (MLv)