Magnitude 0.9, Wed Feb 14 2018 11:12 AM


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Origin


PublicID 2018p118717
UTC Time 2018-02-13T22:12:40Z
Latitude -38.95 (± 1.9 km)
Longitude 175.77 (± 2.3 km)
Depth 7 km (± 3 km)
Depth Type free
Earth Model nz3drx
Used Phase Count 12
Used Station Count 7
Standard Error 0.26 (s)
Azimuthal Gap 115.84 (degrees)
Minimum Distance 0.06 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 0.9  
MLv 0.9 (± 0.2) 3
ML 1.2 (± 0.3) 6
M 0.9 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


-14.0-12.0-10.0-8.0-6.0-4.0-2.00.02.04.06.08.010.012.014.0residual (s)0123Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.0MagnitudeDistance (degrees)Station Magnitudes (MLv)

Station Magnitudes (ML)


0.01.02.0MagnitudeDistance (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)