InDaily has used State Government data released under the open government policy to construct an interactive map showing the location and magnitude of every earthquake recorded in South Australia since 1840.
The state’s earthquakes are mostly the result of events happening thousands of kilometres away, along the edges of Australia’s tectonic plate.
Our plate runs east up past New Zealand, where it is currently colliding with the Pacific plate – and forcing the Kiwi plate beneath it.
SCROLL DOWN TO SEE THE INTERACTIVE MAP
The Australian plate moves northward by about seven centimetres a year. The collisions between the plates lead to massive build-ups of stress, which are transferred across the Australian continent.
The accumulated stresses eventually build to the point where the surrounding earth cannot bear them anymore, and the stress is released in an intraplate earthquake.
Most of South Australia’s seismic activity is concentrated along the Flinders and Mt Lofty ranges, explains senior seismologist at Geoscience Australia Jonathan Bathgate.
“In that area there is an east-west orientated stress, and basically there’s uplift in that area,” Bathgate says. “The Flinders Ranges are actively growing as a result of those stresses.”
Most recently, we’ve seen two very large earthquakes along the border with the Northern Territory.
Perhaps the quake that most sticks in people’s minds though, according to Bathgate, is the 1954 Adelaide earthquake, which struck near the centre of the city with a 5.4 magnitude.
HOW TO USE THE EARTHQUAKE MAP
– Earthquakes are represented by points on the map. The larger the point, the higher the magnitude.
– You can sort the earthquakes by magnitude and year using the two sliders in the top right of the visualisation. Try moving the sliders to find only earthquakes from 1954 – the year of Adelaide’s most famous earthquake.
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