Magnitude 3.8, Tue Oct 13 2020 2:25 AM


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Origin


PublicID 2020p771784
UTC Time 2020-10-12T13:25:45Z
Latitude -33.77 (± 45.8 km)
Longitude -179.07 (± 59.4 km)
Depth 344 km (± 38 km)
Depth Type free
Earth Model iasp91
Used Phase Count 12
Used Station Count 8
Standard Error 0.68 (s)
Azimuthal Gap 352.49 (degrees)
Minimum Distance 4.53 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (MLv) 3.8 (± 0.5)  
ML 3.7 (± 0.4) 7
MLv 3.8 (± 0.5) 4
M 3.8 4

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


-5.0-3.0-1.01.03.05.0residual (s)01234567Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.04.05.0Magnitude567Distance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.04.05.0Magnitude567Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (ML)


-1.00.01.0Residual567Distance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual567Distance (degrees)Magnitude Residuals (MLv)