Magnitude 4.7, Tue Jan 21 2025 1:32 AM


Download Event Information


Origin


PublicID 2025p052769
UTC Time 2025-01-20T12:32:48Z
Latitude -24.61 (± 10.6 km)
Longitude -177.37 (± 21.8 km)
Depth 100 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 10
Used Station Count 9
Standard Error 1.03 (s)
Azimuthal Gap 184.50 (degrees)
Minimum Distance 4.65 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (mB) 4.7  
MLv 5.2 1
mB 4.7 1
Mw(mB) 3.9 (± 0.4) 1
M 5.2 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


-6.0-4.0-2.00.02.04.06.0residual (s)02468101214161820Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.04.05.06.0MagnitudeDistance (degrees)Station Magnitudes (MLv)

Station Magnitudes (mB)


0.01.02.03.04.05.0MagnitudeDistance (degrees)Station Magnitudes (mB)

Magnitude Residuals (MLv)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (mB)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (mB)