Magnitude 2.1, Mon Aug 26 2019 6:04 AM



Download Event Information


Origin


PublicID 2019p639872
UTC Time 2019-08-25T18:04:14Z
Latitude -38.15 (± 7.0 km)
Longitude 178.30 (± 5.8 km)
Depth 12 km (± 10 km)
Depth Type free
Earth Model iasp91
Used Phase Count 13
Used Station Count 9
Standard Error 0.88 (s)
Azimuthal Gap 214.18 (degrees)
Minimum Distance 0.08 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 2.1  
ML 2.5 (± 0.1) 7
MLv 2.1 (± 0.2) 5
M 2.1 5

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)0Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.0Magnitude0Distance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.0Magnitude0Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (ML)


-1.00.01.0Residual0Distance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual0Distance (degrees)Magnitude Residuals (MLv)