Magnitude 4.4, Thu Jun 25 2020 7:25 AM


Download Event Information


Origin


PublicID 2020p475166
UTC Time 2020-06-24T19:25:03Z
Latitude -33.83 (± 19.7 km)
Longitude -178.51 (± 24.0 km)
Depth 206 km (± 47 km)
Depth Type free
Earth Model iasp91
Used Phase Count 13
Used Station Count 9
Standard Error 0.53 (s)
Azimuthal Gap 314.56 (degrees)
Minimum Distance 4.54 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 4.4  
MLv 4.4 (± 0.1) 6
M 4.4 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


-20.0-18.0-16.0-14.0-12.0-10.0-8.0-6.0-4.0-2.00.02.04.06.08.010.012.014.016.018.020.0residual (s)0123456789Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.04.05.0Magnitude56Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (MLv)


-1.00.01.0Residual56Distance (degrees)Magnitude Residuals (MLv)