Magnitude 1.5, Sun Nov 22 2020 10:35 PM

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PublicID 2020p882161
UTC Time 2020-11-22T09:35:35Z
Latitude -38.50 (± 3.4 km)
Longitude 176.28 (± 2.8 km)
Depth 4 km (± 3 km)
Depth Type free
Earth Model iasp91
Used Phase Count 13
Used Station Count 9
Standard Error 0.32 (s)
Azimuthal Gap 89.32 (degrees)
Minimum Distance 0.08 (degrees)


Type Magnitude Station Count
Preferred (M) 1.5  
ML 1.7 (± 0.2) 6
MLv 1.5 (± 0.3) 7
M 1.5 7

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)0Distance (degrees)Pick Residuals

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

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

Magnitude Residuals (ML)

- (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)

- (degrees)Magnitude Residuals (MLv)