Only minor aftershocks overnight in Canterbury

4:58 pm on 9 September 2010

The tired and twitchy people of mid-Canterbury may have got their first decent sleep since last Thursday, with several minor aftershocks but no major ones overnight.

Since 6pm GNS Science has recorded 16 aftershocks, the most recent at 10.47am. The strongest, at 2.50am, had a magnitude of 4.5. Many have been within a 20km radius of Darfield.

Over previous nights, since Saturday's massive original quake, residents have been jolted awake by much stronger and more frequent aftershocks.

There was a sense of relief on Thursday morning around the port of Lyttelton, which was near the centre of Wednesday morning's big aftershock.

GNS Science says Canterbury is probably about halfway through its aftershock sequence. Hazard and risk modeller Warwick Smith says quakes are starting to tail off, but a possible magnitude-6 shock could still be coming in the next few weeks.

City water supply good to gargle

Meanwhile, Christchurch city's water supply has been given the all-clear. Intense testing has failed to find any bacterial contamination, so drinking water in the city and on Banks Peninsula no longer has to be boiled.

Canterbury Chief Medical Officer of Health Alistair Humphrey says the water all-clear has important implications for the food industry. Some producers could not meet export orders, he says, because they were unable to wash vegetables.

Water is now flowing to almost all homes and businesses.

Water still needs to be boiled, however, in Kaiapoi, Pines Beach, Kairaki, Woodend and Waikuku Beach in the Waimakariri district.

Civil Defence says the lower Waimakariri River has become contaminated after Saturday's earthquake, and advises the public to avoid any contact with the water downstream of McLeans Island.

That includes drinking the water and collecting fish or shellfish from the river or river mouth.

Bottled water company SpringFresh has been providing its product free of charge to Christchurch residents on Thursday.

Christchurch and Banks Peninsula residents are now able to drink tap water without boiling it, but SpringFresh still dropped off bottled water at several collection points around the city.

As for power, Orion estimates that only about 200 customers are still disconnected. If anyone without power has not heard from Orion in the past 24 hours, it says, they should call again.