Magnitude 4.2, Wed Sep 17 2014 12:27 AM


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Origin


PublicID 2014p698701
UTC Time 2014-09-16T12:27:36Z
Latitude -47.70 (± 10.4 km)
Longitude 165.47 (± 10.2 km)
Depth 12 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 12
Used Station Count 7
Standard Error 0.54 (s)
Azimuthal Gap 322.43 (degrees)
Minimum Distance 1.75 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 4.2  
MLv 4.2 (± 0.2) 7
ML 4.5 (± 0.1) 7
M 4.2 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


-3.0-2.0-1.00.01.02.03.0residual (s)01234567Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.04.05.0Magnitude23Distance (degrees)Station Magnitudes (MLv)

Station Magnitudes (ML)


0.01.02.03.04.05.0Magnitude23Distance (degrees)Station Magnitudes (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual23Distance (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (ML)


-1.00.01.0Residual23Distance (degrees)Magnitude Residuals (ML)