Magnitude 5.1, Mon May 25 2015 5:27 PM


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Origin


PublicID 2015p389806
UTC Time 2015-05-25T05:27:35Z
Latitude -30.50 (± 30.0 km)
Longitude 179.55 (± 72.3 km)
Depth 326 km (± 78 km)
Depth Type free
Earth Model iasp91
Used Phase Count 15
Used Station Count 9
Standard Error 0.97 (s)
Azimuthal Gap 349.81 (degrees)
Minimum Distance 7.36 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 5.1  
MLv 5.1 (± 0.3) 7
mB 4.7 (± 0.1) 2
Mw(mB) 4.0 (± 0.4) 2
M 5.1 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


-2.0-1.00.01.02.0residual (s)0123456789Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.04.05.06.0Magnitude8Distance (degrees)Station Magnitudes (MLv)

Station Magnitudes (mB)


0.01.02.03.04.05.0Magnitude8Distance (degrees)Station Magnitudes (mB)

Magnitude Residuals (MLv)


-1.00.01.0Residual8Distance (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (mB)


-1.00.01.0Residual8Distance (degrees)Magnitude Residuals (mB)