Earth tremor vs earthquake: What is the difference?

If you're wondering whether you can tell the difference between the two, an expert says it depends on how far are you from the epicentre or point of rupture.

FILE: Hartbeespoort aftermath of the earthquake in 2016. Picture: Supplied.

JOHANNESBURG - While South Africa may not be a natural disaster-prone area, we're not totally immune to earthquakes and tremors and there are many past events to prove it.

But when is it an earthquake and when is it a tremor? We find out from the experts:

"By South African standards, an earthquake would be seismic activity roughly registering around the magnitude of 4.0 and higher, and a tremor would be seismic activity less than a magnitude of 4.0. In a sense, tremors are minor earthquakes. Internationally, especially countries that are more prone to earthquakes than South Africa, the standards could be different, says Eldridge Kgaswane, chief scientist at the Council for Geoscience.


Kgaswane says this is quite subjective. It all depends how far are you from the epicentre or point of rupture.

"I would say if A seismic activity is felt well beyond distances of 500 km or more, then we could from face value interpret it to be an earthquake. Seismic waves attenuate (decrease in energy) as they travel through the earth’s medium and at long distances, the intensity might not be felt."

Meanwhile, do you know what to do during an earthquake? Here's a quick guide Eyewitness News has put together to 'balance you'.

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