Report: quake fears receding

FEARS Geelong is overdue for a serious earthquake appear to have eased with the release of a new quake hazard hotspot map.
Geoscience Australia’s Dr Mark Leonard told the Independent the risk of serious earthquake could be up to one-third less than previously thought in the fault-riddled region.
Geelong is peppered with quake-prone sites from faults north, west, east and south of the city, from Lovely Banks to Leopold, Indented Head, Ocean Grove and Torquay.
“In the previous map of 1991 the level of activity in Geelong and the strip through to Portland was a bit higher,’’ Dr Leonard said.
“In this map Geelong has probably dropped 25 per cent, a slight reduction, maybe by a third.
“When they did the ’91 map they were quite aware of magnitude five-plus quakes off the coast in ’65 and other activities around 4.5, mostly off the coast, but it’s quietened down a bit.’’
Dr Leonard said scientists had only about 10 per cent of the information they needed to gauge quake risks accurately.
“With the last map they had only 30 years data, now we have 60 years. If we knew every quake over the last 500 years it would be good but we have only a tenth of the data we need.”
The National Earthquake Hazard Map of Australia, released this week, will allow planners and engineers to improve buildings and infrastructure designs to withstand tectonic tremors.
About 90 quakes since white settlement have shaken Geelong, the last above magnitude five on the Richter scale almost 50 years ago in 1965.
A PJ Yttrup & Associates report in 2000 found that sites such as Moolap’s CSIRO’s Animal Health Laboratories and Corio’s Shell refinery were on land that could be susceptible to liquefaction in the event of an earthquake.