Magnitude 3.3, Mon Sep 4 2023 12:13 PM


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Origin


PublicID 2023p664889
UTC Time 2023-09-04T00:13:10Z
Latitude -37.71 (± 34.2 km)
Longitude 175.21 (± 62.9 km)
Depth 33 km (± 103 km)
Depth Type free
Earth Model nz3drx
Used Phase Count 9
Used Station Count 9
Standard Error 1.64 (s)
Azimuthal Gap 207.92 (degrees)
Minimum Distance 0.94 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 3.3  
ML 3.0 (± 0.4) 7
MLv 3.3 (± 0.4) 4
M 3.3 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


-4.0-3.0-2.0-1.00.01.02.03.04.0residual (s)012Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.04.0Magnitude12Distance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.04.0Magnitude1Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (ML)


-1.00.01.0Residual12Distance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual1Distance (degrees)Magnitude Residuals (MLv)