Magnitude 5.3, Fri Jul 20 2018 6:30 AM


Download Event Information


Origin


PublicID 2018p539935
UTC Time 2018-07-19T18:30:33Z
Latitude -6.15 (± 0.0 km)
Longitude 148.70 (± 0.0 km)
Depth 31 km (± 0 km)
Depth Type free
Earth Model
Used Phase Count 0
Used Station Count 0
Standard Error 1.15 (s)
Azimuthal Gap 0.00 (degrees)
Minimum Distance 0.00 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (M) 5.3  
mB 5.8 (± 0.2) 12
Mw(mB) 5.3 (± 0.4) 12
M 5.3 12

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)024681012141618202224262830323436384042Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.06.07.0Magnitude41Distance (degrees)Station Magnitudes (mB)

Magnitude Residuals (mB)


-1.00.01.0Residual41Distance (degrees)Magnitude Residuals (mB)