Magnitude 2.3, Tue Feb 23 2021 4:59 PM

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PublicID 2021p143692
UTC Time 2021-02-23T03:59:17Z
Latitude -37.61 (± 0.0 km)
Longitude 175.06 (± 0.0 km)
Depth 0 km (± 0 km)
Depth Type free
Earth Model
Used Phase Count 0
Used Station Count 0
Standard Error 0.82 (s)
Azimuthal Gap 0.00 (degrees)
Minimum Distance 0.00 (degrees)


Type Magnitude Station Count
Preferred (M) 2.3  
MLv 2.3 (± 0.4) 2
ML 1.9 (± 0.3) 6
M 2.3 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

-2.0- (s)01Distance (degrees)Pick Residuals

Station Magnitudes (MLv) (degrees)Station Magnitudes (MLv)

Station Magnitudes (ML) (degrees)Station Magnitudes (ML)

Magnitude Residuals (MLv)

- (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (ML)

- (degrees)Magnitude Residuals (ML)