Magnitude 4.0, Fri Oct 13 2023 7:23 AM


Download Event Information


Origin


PublicID 2023p769642
UTC Time 2023-10-12T18:23:59Z
Latitude -32.55 (± 28.9 km)
Longitude 179.89 (± 56.8 km)
Depth 100 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 10
Used Station Count 8
Standard Error 0.81 (s)
Azimuthal Gap 350.13 (degrees)
Minimum Distance 5.17 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (Mw(mB)) 4.0 (± 0.4)  
mB 4.7 (± 0.2) 6
Mw(mB) 4.0 (± 0.4) 4
ML 3.9 (± 0.4) 2
MLv 4.1 (± 0.1) 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


-8.0-6.0-4.0-2.00.02.04.06.08.0residual (s)012345678Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.06.0Magnitude67Distance (degrees)Station Magnitudes (mB)

Station Magnitudes (ML)


0.01.02.03.04.05.0Magnitude6Distance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.04.05.0Magnitude6Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (mB)


-1.00.01.0Residual67Distance (degrees)Magnitude Residuals (mB)

Magnitude Residuals (ML)


-1.00.01.0Residual6Distance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual6Distance (degrees)Magnitude Residuals (MLv)