Magnitude 6.1, Fri Aug 17 2018 6:22 AM


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Origin


PublicID 2018p615599
UTC Time 2018-08-16T18:22:53Z
Latitude 23.44 (± 0.0 km)
Longitude 143.31 (± 0.0 km)
Depth 20 km (± 0 km)
Depth Type free
Earth Model
Used Phase Count 0
Used Station Count 0
Standard Error 0.90 (s)
Azimuthal Gap 0.00 (degrees)
Minimum Distance 0.00 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (mB) 6.1 (± 0.3)  
mB 6.1 (± 0.3) 6
Mw(mB) 5.8 (± 0.4) 6
M 5.8 6

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


-2.0-1.00.01.02.0residual (s)0246810121416182022242628303234363840424446485052545658606264666870Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.06.07.0Magnitude71Distance (degrees)Station Magnitudes (mB)

Magnitude Residuals (mB)


-1.00.01.0Residual71Distance (degrees)Magnitude Residuals (mB)