Magnitude 1.8, Thu Jun 2 2011 11:02 PM


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Origin


PublicID 3523487
UTC Time 2011-06-02T11:02:08Z
Latitude -37.03 (± 0.0 km)
Longitude 175.19 (± 0.0 km)
Depth 5 km (± 0 km)
Depth Type operator assigned
Earth Model nz1dr
Used Phase Count 9
Used Station Count 5
Standard Error 0.12 (s)
Azimuthal Gap 209.00 (degrees)
Minimum Distance 0.08 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (ML) 1.8 (± 0.1)  
ML 1.8 (± 0.1) 2

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


-1.00.01.0residual (s)0Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.0Magnitude0Distance (degrees)Station Magnitudes (ML)

Magnitude Residuals (ML)


-1.00.01.0Residual0Distance (degrees)Magnitude Residuals (ML)