aftershocks

Still chance of a big aftershock

by Isaac Davison (Chch Star 8 sept 2010 p3).

There is still the chance of a large aftershock in Christchurch and surrounding Canterbury towns as the releif effort entered its fifth day today.

Saturday's 7.1 magnitude earthquake struck some 30km west of the city, near the town of Darfield and broguht the city almost to its knees.

GNS is WARNING that shakes will continue for WEEKS and there was still the chance of a magnitude 6 shake.

Geophysics professor Euan Smith, from Victoria university, said there was reason to beleive the Canturbury quake could be part of a series of large tremors.

In 1929 there occured in west Canterbury a magnitude 7 earthquake which turned out to be the first of a series of seven major magnitude greater than 7. earthquakes over the next 13 years. The series included the second and third largest earthquakes in European times. It is improbable that this occurance of such large earthquakes in rapid sucession was cooincidental.

There is no reason to think that such a series could not happen again.

Rebuilding the estimated 100,000 damaged and destroyed homes in the region is predicted to take months if not years. Damage assessments have only just begun. and while some buildings have been demolished in the days following the 7.1 earthquake they have been knocked down for safety reasons.

The city council has stopped any new building going ahead for the next two weeks. Power cuts are to be expected while networks remain fragile. Will schools reopen on Monday?