Magnitude 2.9, Wed Aug 16 2017 1:31 PM


Download Event Information


Origin


PublicID 2017p613685
UTC Time 2017-08-16T01:31:52Z
Latitude -46.60 (± 5.0 km)
Longitude 167.23 (± 4.7 km)
Depth 12 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 14
Used Station Count 8
Standard Error 0.50 (s)
Azimuthal Gap 204.45 (degrees)
Minimum Distance 0.48 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 2.9  
MLv 2.9 (± 0.2) 4
ML 3.0 (± 0.1) 7
M 2.9 4

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


-3.0-2.0-1.00.01.02.03.0residual (s)012Distance (degrees)Pick Residuals

Station Magnitudes (MLv)


0.01.02.03.04.0Magnitude1Distance (degrees)Station Magnitudes (MLv)

Station Magnitudes (ML)


0.01.02.03.04.0Magnitude1Distance (degrees)Station Magnitudes (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual1Distance (degrees)Magnitude Residuals (MLv)

Magnitude Residuals (ML)


-1.00.01.0Residual1Distance (degrees)Magnitude Residuals (ML)