Magnitude 1.4, Sat Feb 17 2018 11:56 PM


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Origin


PublicID 2018p128259
UTC Time 2018-02-17T10:56:31Z
Latitude -38.63 (± 3.1 km)
Longitude 176.24 (± 3.9 km)
Depth 5 km (± 4 km)
Depth Type free
Earth Model iasp91
Used Phase Count 13
Used Station Count 8
Standard Error 0.22 (s)
Azimuthal Gap 93.70 (degrees)
Minimum Distance 0.07 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 1.4  
MLv 1.4 (± 0.4) 8
ML 1.8 (± 0.4) 8
M 1.4 8

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)01Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.0MagnitudeDistance (degrees)Station Magnitudes (MLv)

Station Magnitudes (ML)


0.01.02.03.0MagnitudeDistance (degrees)Station Magnitudes (ML)

Magnitude Residuals (MLv)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (ML)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (ML)