2009 Dusky Sound earthquake
 | |
| UTC time | ?? |
|---|---|
| Magnitude | 7.8 Mw |
| Depth | 12 kilometres (7 mi) |
| Epicenter | 45°43′16″S 166°38′35″E / 45.721°S 166.643°E |
| Areas affected |  New Zealand Australia |
| Tsunami | 1 m (39 in) |
| Casualties | 0 |
The 2009 Fiordland earthquake was a magnitude 7.8 earthquake[1] that struck the South Island of New Zealand at 9:22 pm (NZST) on 15 July 2009. The earthquake was centred in the remote region of Fiordland, with the epicentre located 150 km (93 mi) west-north-west of Invercargill near Dusky Sound in Fiordland National Park, at a depth of 12 km (7.5 mi).[2] [3] It is the largest New Zealand earthquake since the 1931 Hawke's Bay earthquake, which also had a magnitude of 7.8.[4]
The main shock was a reverse fault (thrust), with the Indo-Australian Plate subducting beneath the Pacific Plate.[4] The earthquake lifted a large area of land around the epicenter approximately 1 metre.[5]
New Zealand's Institute of Geological and Nuclear Sciences (GNS Science) initially measured the earthquake at magnitude 6.6,[6] but later revised the magnitude to 7.8.[7] The earthquake was felt throughout the South Island, and in the lower North Island as far as New Plymouth. No injuries or fatalities were reported, and it caused only minor damage.[7] Power outages were experienced in several parts of the South Island.[8][9]
A large aftershock was reported at 9:41 pm,[7] measuring between 5.8 (US Geological Survey) and 6.1 (GNS Science) on the Richter scale, at a depth of 5 km (3.1 mi).[10] GNS Science reported that the aftershock was also felt in the lower North Island.[7]
Tsunami warnings were issued soon after the earthquake by authorities in New Zealand and Australia, as well as the Pacific Tsunami Warning Center in Hawaii.[11] Waves were recorded along New Zealand's western coastline, with a meter at Jackson Bay, Haast, measuring the wave at one metre, peak to trough.[4] The tsunami warnings were subsequently cancelled or reduced.[7] Civil defence officials in Southland also issued a 'potential tsunami' warning, stating their concerns about widely varying measurements of the earthquake.[8]
The quake could also be very faintly felt in places as far as Australia. In Sydney, few occurrences of chairs slightly vibrating at the time of the earthquake in tall buildings were recorded.
See also
References
- ^ "Tsunami May Reach New Zealand Cities After 7.8 Quake". Bloomberg. 2009-07-15. Retrieved 2009-07-15.
- ^ "Magnitude 7.8 - OFF WEST COAST OF THE SOUTH ISLAND, N.Z." USGS. 2009-07-15, 09:22:32 UTC. Retrieved 2009-07-15.
{{cite web}}: Check date values in:|date=(help) - ^ "New Zealand Earthquake Report - Jul 15 2009 at 9:22 pm (NZST)". GeoNet. 2009-07-15, 09:22 UTC. Retrieved 2009-07-16.
{{cite web}}: Check date values in:|date=(help) - ^ a b c ""Fiordland quake biggest for 80 years"". GeoNet. Institute of Geological and Nuclear Sciences. 16 July 2009.
- ^ "Ground raised one metre by quake". Radio New Zealand. 2009-07-18.
- ^ "Tsunami alert after NZ earthquake". BBC News. 15 July 2009. Retrieved 2009-07-15.
- ^ a b c d e NZPA, Fairfax (2009-07-15). "Fiordland quake measures 7.8". stuff.co.nz. Retrieved 2009-07-15.
- ^ a b Dye, Stuart; NZPA (2009-07-15). "South Island quake prompts 'potential tsunami' warning". The New Zealand Herald. Retrieved 2009-07-15.
- ^ "Quake strikes off New Zealand's Southland". Xinhua. 2009-07-15. Retrieved 2009-07-15.
- ^ AAP (2009-07-15). "Tsunami warning for east coast of Australia". news.com.au. Retrieved 2009-07-15.
- ^ "New Zealand quake sparks tsunami warnings". Reuters. 2009-07-15. Retrieved 2009-07-15.