National Advisory: Tsunami activity. Please see NEMA (The National Emergency Management Agency) for official advice.
This earthquake followed the magnitude 6.5 Cook Strait earthquake on 21st July. It caused damage to buildings on both sides of Cook Strait.
| PublicID | 2013p613797 |
| UTC Time | 2013-08-16T02:31:05Z |
| Latitude | -41.70 (± 2.1 km) |
| Longitude | 174.16 (± 2.2 km) |
| Depth | 7 km (± 3 km) |
| Depth Type | free |
| Earth Model | nz3drx |
| Used Phase Count | 40 |
| Used Station Count | 37 |
| Standard Error | 0.52 (s) |
| Azimuthal Gap | 64.71 (degrees) |
| Minimum Distance | 0.06 (degrees) |
| Type | Magnitude | Station Count |
| Preferred (M) | 6.5 | |
| MLv | 6.5 (± 0.3) | 30 |
| ML | 6.5 (± 0.3) | 11 |
| M | 6.5 | 30 |
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).
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.