Kalgoorlie earthquake reveals vulnerability

26 November 2010

Researchers investigating an earthquake earlier this year below the Kalgoorlie suburb of Boulder in Western Australia have found there are widely differing effects on buildings of different ages and construction.

Earthquake damage to the Golden Eagle Hotel. Image courtesy: Fire and Emergency Services Authority of Western Australia

Earthquake damage to
the Golden Eagle Hotel.
Image courtesy:
Fire and Emergency Services
Authority of Western Australia

Since the magnitude 5 event on 20 April 2010 scientists from Geoscience Australia, The University of Adelaide and The University of Melbourne have been gathering information on the effects of the earthquake and subsequent aftershocks. Initially, the team obtained 230 000 street view images within Kalgoorlie using Geoscience Australia's vehicle mounted Rapid Inventory Collection System (RICS).  Then they conducted a more detailed assessment of the effects of the earthquake on more than 400 buildings of various ages.

Speaking at the Australian Earthquake Engineering Society conference in Perth, a member of Geoscience Australia's Risk and Impact Analysis Group, Martin Wehner, said that older masonry buildings were particularly vulnerable to the nature of the ground motion and shaking experienced in the Kalgoorlie event.

"There was widespread damage caused to pre-World War I un-reinforced masonry buildings, which lost chimneys, gables and parapets and suffered extensive wall cracking," Mr Wehner said.

"At the same time, while those of more contemporary cavity brick construction experienced less damage than older masonry buildings, they suffered greater damage than equivalent framed constructions," he said.

Geoscience Australia also obtained valuable information on earthquake shaking from its permanent national seismograph network as well as from temporary stations positioned around the epicentre which recorded 544 events during 47 days following the quake on 20 April.

"We will combine these observations of ground shaking and building damage to improve our understanding of the effects of the Kalgoorlie event and use this information for future assessments of earthquake risk," Mr Wehner said.

"This will help with the development of management practices to mitigate possible damage in earthquake prone areas," he said.

A more detailed report can be found in AusGeo News 100.

Topic contact: media@ga.gov.au Last updated: October 4, 2013