标题: major earthquake [打印本页] 作者: angelangelangel 时间: 18-4-2010 15:16 标题: major earthquake SA could have major earthquake LAUREN ZWAANS From: Sunday Mail (SA) April 19, 2009 12:30AM 3 commentsIncrease Text SizeDecrease Text SizePrintEmail Share
Add to DiggAdd to del.icio.usAdd to FacebookAdd to KwoffAdd to MyspaceAdd to NewsvineWhat are these?AN earthquake similar in scale to the one that destroyed L'Aquilla, Italy, could be in store for Adelaide next year, a leading seismologist says.
Australian Seismological Centre director Kevin McCue says according to statistical theory, 2010 poses the highest risk for an earthquake of magnitude six or larger in SA.
"The reality is that the most probable year for a damaging earthquake is next year, according to the theory of extreme values," he said.
"Looking ahead from today, you'd say next year has a higher risk than any other subsequent year. We know it's going to happen some time."
Extreme value theory is a specialist branch of mathematics used to predict rare events such as earthquakes, hurricanes and stock market crashes by assessing probability. The last big earthquake to hit South Australia shook half the state from an epicentre near Darlington on March 1, 1954.
The magnitude 5.5 quake - considered moderate - damaged hundreds of houses across the southern suburbs, turning several into rubble.
Heavy tremors even reached the CBD, with several city buildings, including the GPO, sustaining damage. By today's standards, the total cost of the 1954 quake would be more than $70 million.
Mr McCue said it would not be unusual for a "strong" quake similar to L'Aquilla's - of magnitude six or greater - to hit SA. "In any 100-year period, Australia would expect 10 earthquakes on the scale of L'Aquilla," he said.
"You would expect about three to four of those would occur across SA and the Northern Territory."
Mr McCue signalled four earthquake hot zones in SA. He said the South-East, the Mid North, the Eyre Peninsula through to the southern part of Yorke Peninsula and the Flinders and Mount Lofty ranges were the most likely spots for tremors.
He said any shocks that occurred in the Flinders were likely to also affect Adelaide.
Mr McCue said SA was "not well prepared" for a larger earthquake.
"We don't want to see people in schools and hospitals killed in an earthquake," he said.
"Governments have a very strong responsibility to make sure those buildings are adequate. Unreinforced masonry buildings and also reinforced concrete buildings are particularly vulnerable.
"The RAH is an old hospital - these are the buildings to be looked at."
Industrial designer Michael Angerson, who specialises in earthquake-resistant building design, labelled Adelaide buildings "very unsafe". He said concrete slabs used in homes would crack and crumble.
"If you're talking of an earthquake the same size as Italy, at least 50 per cent of our modern houses would go," he said. "We'd be in worse trouble than we were in the '50s because we've insisted on these concrete slabs.
It doesn't matter how far you sink the foundation, an earthquake will just rip it up.
"It's pretty dangerous stuff and yet councils insist on that sort of (design), which is dangerously arrogant and not very scientific."
But Primary Industries and Resources SA seismologist David Love said based on recent large earthquakes in places like Newcastle, NSW, most Adelaide buildings would "survive fairly well".
"We need to pay some attention, but we don't need to go overboard," he said.
Mr Love said while Adelaide had a higher risk of earthquakes than other capital cities, the probability of a disastrous quake in the CBD was "very low". "Having said that, we can't rule it out," he said.
Mr Love said people could prepare for earthquakes and other emergencies by keeping a torch, batteries and a battery radio near their bed.
He said home-owners should check insurance policies to ensure they were properly covered for quake damage.