Magnitude 2.2, Tue Sep 27 2016 10:07 PM


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Origin


PublicID 2016p730756
UTC Time 2016-09-27T09:07:05Z
Latitude -42.29 (± 2.5 km)
Longitude 173.03 (± 4.4 km)
Depth 7 km (± 6 km)
Depth Type free
Earth Model tab
Used Phase Count 15
Used Station Count 8
Standard Error 1.05 (s)
Azimuthal Gap 118.88 (degrees)
Minimum Distance 0.40 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (ML) 2.2 (± 0.3)  
ML 2.2 (± 0.3) 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


-3.0-2.0-1.00.01.02.03.0residual (s)012Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.0Magnitude1Distance (degrees)Station Magnitudes (ML)

Magnitude Residuals (ML)


-1.00.01.0Residual1Distance (degrees)Magnitude Residuals (ML)