Magnitude 1.6, Fri Dec 11 2020 12:43 AM

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PublicID 2020p931049
UTC Time 2020-12-10T11:43:22Z
Latitude -39.27 (± 3.2 km)
Longitude 174.06 (± 2.3 km)
Depth 7 km (± 6 km)
Depth Type free
Earth Model iasp91
Used Phase Count 16
Used Station Count 9
Standard Error 0.52 (s)
Azimuthal Gap 91.69 (degrees)
Minimum Distance 0.03 (degrees)


Type Magnitude Station Count
Preferred (M) 1.6  
ML 1.6 (± 0.1) 6
MLv 1.6 (± 0.2) 6
M 1.6 6

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

- (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)