In the event of an earthquake, remember to Drop! Cover! Hold!
To find out how you can be prepared for an earthquake visit sa.gov.au/emergency/earthquake
HistoryThere have been 3 earthquakes since 1837 that have caused some damage to Adelaide. These were in 1897, 1902, and 1954. The last of these was the smallest, but also the closest and most damaging.
There have been very few earthquakes occurring near Adelaide over the last decade; only about 1 per year within 30 km of the city. The low accuracy with which the epicentres can be calculated makes it difficult to tell if the events that have occurred are on the major fault lines near Adelaide.
From experience in the Flinders Ranges it would appear that the earthquakes are scattered widely and do not cluster along the faults. It is therefore considered that although the next major event may occur on a known fault line, there is also a very good probability that it will not. (A 3D model of Flinders Ranges Earthquake Hypocentres is available for download.)
The most common damage from earthquakes includes:
- Poor quality mortar, or no mortar at all, leading to collapsed walls
- Tall brick chimneys which break easily
- Corroded ties between walls, or no ties at all, leading to wall collapse
- Gable ends which have no support at the top
- Parapets that are cracked or have not lateral support
- Suspended awnings where the supporting structure is not strong enough
The question of risk is related more directly to intensity than magnitude. (The worst damage to Adelaide was caused by the smallest of the 3 large events, but it was the closest.) The average return period for damage (MM VI) in Adelaide is thought to be about 180 years, but it could be considerably more or less.
Higher intensities may occur, but with much lower probabilities.
For more information on earthquakes, download Earth Science Information Sheet M13 Faults, earthquakes and house damage
For more information, contact:
Senior Geophysicist Seismologist
+61 8 8463 3177