UQ scientists detect earthquake sequence

University of Queensland seismologists have recorded a sequence of earthquakes in Queensland and northern New South Wales over the past month.

The earthquakes were recorded by seismographs operated by the Queensland University Advanced Centre for Earthquake Studies (QUAKES) and the Australian Geological Survey Organisation (AGSO).

QUAKES senior observer Col Lynam said there was no need for alarm, but there was a need for communities to be aware of the earthquake risk in their built environment.

The earthquakes being investigated include:

- April 29, near Eidsvold, 9.37am EST, magnitude approximately 2.0 (possible aftershock to the February 14 earthquake south-west of Eidsvold earthquake). Recorded on SEQ net.

- April 30, 7km north-west of Helidon, Brisbane Valley, 3.36pm EST, magnitude 1.4. Recorded on Wivenhoe Dam net.

- April 30, widely felt Wonga Valley (west of Gympie), 5.19pm EST. Not recorded (thought to be a sonic blast).

- May 11, felt near Texas (south-east Queensland border region), 8.13 am EST. Nearest seismograph station (RMQ) damaged due to flooding.

- May 13, Port Macquarie New South Wales, 1.46am EST, magnitude 2.3. Felt in region. Recorded at Brisbane seismograph station.

- May 17, Gulf of Carpentaria, 1.56am EST, magnitude 4.3. No felt reports. Recorded at Charters Towers seismograph station. Several other events in this region during 1997-1998.

- May 17, Hungerford on south-west Queensland border, felt 10.30am EST. Few felt reports. Preliminary magnitude ~2.5. Recorded at Brisbane seismograph station.

- May 23, (epicentres being located) occurring 5.04am EST and 8.09am EST. Recorded at Brisbane seismograph station.

Mr Lynam said some of the activity had been felt by the public who then reported their observations to QUAKES.

These reports were of great assistance to QUAKES seismologists, especially when they came from areas where there were no nearby seismographs, he said.

Other earthquakes had been detected from one or more of the University's remotely located, portable seismograph stations, he said.

'These are operated by volunteer ?quake-watchers', who allow QUAKES to place the sensitive instruments in their backyard or on some quiet location on their farm,' Mr Lynam said.

'These people also assist QUAKES by changing records or tapes or allowing modem access to the instrument via their home telephone.
The voluntary action of these people greatly extends QUAKES' ability to estimate the seismic hazard of Queensland and northern New South Wales. Local councils and water boards also assist with earthquake detection.'

Mr Lynam said that any person who suspected they had felt an earthquake should notify him at his office in Brisbane (telephone 07 3365 3197 or facsimile 07 3365 7347).

QUAKES was not only monitoring earthquakes as they occurred, but was also researching the possibility of forecasting earthquake hazards in the seismogenic regions of the State as part of a multi-lateral initiative developed by QUAKES called the APEC Co-operation for Earthquake Simulation (ACES) involving top research groups from China, Japan and the United States, he said.

For more information, contact Mr Lynam (telephone 07 3365 3197, facsimile 07 3365 7347, Internet: http://quakes.earthsciences.uq.edu.au).