Magnitude 4.3, Fri Dec 8 2017 12:10 PM



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Origin


PublicID 2017p921536
UTC Time 2017-12-07T23:10:00Z
Latitude -15.26 (± 0.0 km)
Longitude -173.47 (± 0.0 km)
Depth 10 km (± 0 km)
Depth Type free
Earth Model
Used Phase Count 0
Used Station Count 0
Standard Error 3.27 (s)
Azimuthal Gap 0.00 (degrees)
Minimum Distance 0.00 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 4.3  
mB 5.0 (± 0.2) 5
Mw(mB) 4.3 (± 0.4) 5
M 4.3 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


-6.0-4.0-2.00.02.04.06.0residual (s)02468101214161820222426Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.06.0Magnitude012Distance (degrees)Station Magnitudes (mB)

Magnitude Residuals (mB)


-1.00.01.0Residual012Distance (degrees)Magnitude Residuals (mB)