Magnitude 2.2, Thu Jul 25 2019 2:27 AM


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Origin


PublicID 2019p552980
UTC Time 2019-07-24T14:27:40Z
Latitude -37.18 (± 33.1 km)
Longitude 176.70 (± 31.7 km)
Depth 185 km (± 39 km)
Depth Type free
Earth Model iasp91
Used Phase Count 12
Used Station Count 9
Standard Error 0.32 (s)
Azimuthal Gap 297.93 (degrees)
Minimum Distance 1.04 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 2.2  
ML 2.5 (± 0.2) 7
MLv 2.2 (± 0.2) 3
M 2.2 3

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


-1.00.01.0residual (s)01Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.04.0MagnitudeDistance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.0MagnitudeDistance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (ML)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (MLv)