The 2013 Lake Grassmere earthquake[2] was a magnitude 6.6 earthquake that occurred at 2:31:05 pm (NZST) on Friday 16 August 2013.[3] The epicentre was located about 10 km south-east of Seddon, under Lake Grassmere, with a focal depth of 8 km. The earthquake caused significant land damage in the local area, with landslips blocking roads, including the main highway between Blenheim and Christchurch. Buildings in Seddon were damaged, with some being declared uninhabitable. The earthquake was widely felt in both the North and South Islands of New Zealand.
  | |
| UTC time | 2013-08-16 02:31:09 |
|---|---|
| ISC event | 604020963 |
| USGS-ANSS | ComCat |
| Local date | 16 August 2013 |
| Local time | 14:31:05 NZST |
| Magnitude | 6.6 Mww |
| Depth | 8 kilometres (5 mi) |
| Epicentre | 41°44′S 174°09′E / 41.73°S 174.15°E |
| Areas affected | New Zealand |
| Max. intensity | MMI VIII (Severe) |
| Tsunami | None |
| Casualties | 4 people injured[1] |
Earthquake
edit
This earthquake is considered to be a doublet[4] of a magnitude 6.5 earthquake that occurred in Cook Strait on 21 July 2013 and is thought to have occurred on part of the same complex of faults.[5] It started its own aftershock sequence, with several magnitude 5 and one magnitude 6 earthquakes occurring in the first few hours after the main shock.[4]
Aftershocks
editThe earthquake generated a significant series of aftershocks, the largest of which had a magnitude of 6.0.
Below is a list of all aftershocks magnitudes 5.0 and above that occurred in the region between 16 August 2013 and 5 September 2013.
| Date (NZST) | Time (NZST) | Magnitude (MW) | Magnitude (Mb) | Magnitude (ML) | Epicentre | Depth |
|---|---|---|---|---|---|---|
| 16 August 2013 | 2:31:05 pm | 6.5[6] | 6.0[6] | 6.6[7] | 10 km southeast of Seddon | 8 km |
| 16 August 2013 | 2:37:27 pm | 5.4[8] | 5.4[9] | 5 km southeast of Seddon | 9 km | |
| 16 August 2013 | 2:45:27 pm | 5.5[10] | 5.1[10] | 5.4[11] | 10 km southeast of Seddon | 6 km |
| 16 August 2013 | 2:56:27 pm | 4.9[12] | 5.0[13] | 20 km east of Seddon | 9 km | |
| 16 August 2013 | 3:09:08 pm | 5.9[14] | 5.4[14] | 5.5[15] | 10 km south of Seddon | 8 km |
| 16 August 2013 | 3:21:31 pm | 5.1[16] | 5.0[17] | 10 km south of Seddon | 17 km | |
| 16 August 2013 | 3:51:35 pm | 5.1[18] | 5.2[18] | 5.6[19] | 10 km east of Seddon | 19 km |
| 16 August 2013 | 5:31:16 pm | 5.9[20] | 5.8[20] | 6.0[21] | 15 km east of Seddon | 14 km |
| 16 August 2013 | 5:56:10 pm | 5.0[22] | 5 km northwest of Seddon | 10 km | ||
| 16 August 2013 | 5:57:52 pm | 4.8[23] | 5.1[24] | 20 km east of Seddon | 5 km | |
| 16 August 2013 | 6:42:40 pm | 5.2[25] | 20 km east of Seddon | 20 km | ||
| 16 August 2013 | 6:55:58 pm | 5.0[26] | 5.5[27] | 20 km east of Seddon | 20 km | |
| 16 August 2013 | 8:38:54 pm | 4.7[28] | 4.6[28] | 5.2[29] | 10 km southeast of Seddon | 22 km |
| 17 August 2013 | 4:13:20 pm | 4.8[30] | 5.0[31] | 15 km southwest of Seddon | 20 km | |
| 17 August 2013 | 8:58:39 pm | 5.2[32] | 5.1[32] | 5.5[33] | 10 km south of Seddon | 20 km |
| 18 August 2013 | 4:07:52 am | 4.6[34] | 4.4[34] | 5.0[35] | 5 km southeast of Seddon | 20 km |
| 5 September 2013 | 12:04:10 am | 4.8[36] | 5.1[37] | 35 km northeast of Seddon | 16 km |
Damage
editIn Wellington, the earthquake caused minor damage to buildings, breaking some display windows and cracking plaster. Many central city office workers left work early, and with all suburban train services cancelled for urgent track inspections, bus services overloaded and traffic gridlock occurred on major roads out of the city for a couple of hours. The City Council ordered the deconstruction of a 30-year-old lift shaft that had been damaged in a previous earthquake in July, after recently installed emergency seismic restraints failed. Several surrounding buildings in the fall zone were ordered to be evacuated.[citation needed] In the Wellington Region, 2,500 homes were left without power immediately after the earthquake. Most homes had power restored within an hour.[38] Power was restored to 7,500 properties in Wellington City, Kāpiti Coast and Wainuiomata by 5 pm. Phone lines were also overwhelmed. State Highway 1 between Blenheim and Kaikōura was closed for the night after the earthquake.[39] Wellington Airport temporarily closed to check for runway damage.[40] By July 2014, the Earthquake Commission had paid out a total $23.4 million for 8,221 claims in response to the July and August earthquakes.[41]
Seddon
editThe quake caused substantial damage to a number of residential homes in the Seddon area. Eight houses were evacuated by The Marlborough District Council[42] and another 11 allowed only restricted access.
Rest of New Zealand
editThe quake was felt as far north as Auckland and far south as Dunedin.[citation needed] Damage was reported in the Kāpiti Coast, Hutt Valley, Wellington, Blenheim, Ward and the rest of West Upper South Island.[43]
See also
editReferences
edit- ^ "M 6.6, Lake Grassmere, 16 August 2013 – Earthquake – GeoNet". info.geonet.org.nz. Retrieved 11 December 2015.
- ^ Fenaughty, Kevin (17 August 2013). "Damaging quake hits the north-east of the South Island". GeoNet. Retrieved 17 August 2013.
- ^ "New Zealand Earthquake Report – Magnitude 6.6, Friday, August 16, 2013 at 2:31:05 pm (NZST)". GNS Science. Retrieved 17 August 2013.
- ^ a b "M 6.6 Lake Grassmere Fri, Aug 16 2013". GeoNet. Retrieved 23 November 2018.
- ^ "Little fault blamed for big jolt". Stuff. Retrieved 23 November 2018.
- ^ a b "M6.5 – 29 km SE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M5.4 – 25 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M5.5 – 30 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M4.9 – 27 km ESE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M5.9 – 26 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M5.1 – 30 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M5.1 – 27 km SE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M5.9 – 30 km ESE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M4.8 – 35 km ESE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M5.0 – 33 km ESE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M4.7 – 28 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M4.8 – 29 km S of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M5.2 – 29 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ a b "M4.6 – 31 km SSE of Blenheim, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ "M4.8 – 34 km SW of Brooklyn, New Zealand". United States Geological Survey. Retrieved 11 December 2015.
- ^ "GeoNet – Quakes". GeoNet. Retrieved 11 December 2015.
- ^ Davidson, Helen (16 August 2013). "New Zealand earthquake hits near Wellington". The Guardian. ISSN 0261-3077. Retrieved 13 March 2024.
- ^ "Quake-rattled residents flee after tremors". New Zealand: Stuff. 17 August 2013. Retrieved 22 October 2024.
- ^ "Quake strikes south of New Zealand capital Wellington". Australia: ABC News. 16 August 2013. Retrieved 13 March 2024.
- ^ Duggan, Kat (21 July 2014). "EQC pays out $18m so far". Retrieved 13 May 2024.
- ^ "Inspections find every Seddon property damaged". RNZ. 22 October 2024. Retrieved 22 October 2024.
- ^ "Thousands of claims for Cook Strait quake damage". The New Zealand Herald. 22 October 2013. Retrieved 22 October 2024.
External links
edit- The International Seismological Centre has a bibliography and/or authoritative data for this event.