Magnitude 5.3, Fri Apr 16 2021 12:32 AM


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Origin


PublicID 2021p282498
UTC Time 2021-04-15T12:32:22Z
Latitude -29.37 (± 9.8 km)
Longitude -176.93 (± 10.5 km)
Depth 10 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 11
Used Station Count 8
Standard Error 1.13 (s)
Azimuthal Gap 285.83 (degrees)
Minimum Distance 0.87 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (mB) 5.3 (± 0.8)  
ML 5.0 1
MLv 4.9 1
mB 5.3 (± 0.8) 2
Mw(mB) 4.8 (± 0.8) 2
M 4.9 1

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)0246810121416Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.04.05.06.0MagnitudeDistance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.04.05.0MagnitudeDistance (degrees)Station Magnitudes (MLv)

Station Magnitudes (mB)


0.01.02.03.04.05.06.0MagnitudeDistance (degrees)Station Magnitudes (mB)

Magnitude Residuals (ML)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (mB)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (mB)