The KwaZulu-Natal coastline was hit by a jarring earth tremor on Thursday afternoon, taking everyone in the province by surprise.While there has been speculation that the tremor was linked to the south Philippines earthquake, experts disagree, saying it was isolated to KZN.So, what exactly happened?According to Council of Geoscience spokesperson Mahlatse Mononela, Thursday's event was a natural occurrence."Current estimates show that yesterday's event was probably produced by a normal fault."Should we expect this again?Mononela said like any event of this nature, mother nature had to go through the "birth" and "death" cycle."There is likely to be a recurrence if the fault in this area is active. How far apart in terms of time? We do not know since there is currently no technology in the world to predict earthquakes. "According to our latest investigation, there was a [magnitude 3.8] earthquake of similar size back in 1987 in this area. Therefore, this fault is old, perhaps not as active as others elsewhere in the country."What is SA's history with earthquakes and tremors?Mononela said earthquakes could also be caused by volcanic activity, landslides, mine blasts and nuclear tests.She added that South Africa had gold, platinum and coal mines, which almost on a daily basis, produce some forms of tremors due to blasting."Most of the earthquakes in South Africa are mining-related and there is less of a natural seismic activity because it sits on an intraplate zone that is a stable continental region. "Typical settings are Australia and the eastern parts of the US as well as some parts of Canada, Europe, Asia and Africa that basically sit on cratonic [stable] continental regions."So, what should you do if caught in a tremor or earthquake?According to Mononela, the Council for Geosciences usually preached the DCH (D for drop, C for cover and H for hold) philosophy to the public."This means that when an earthquake happens and you are inside a building, simply drop and take cover under things like a table [to avoid falling objects] and hold until the earthquake dies down. "When you are outside, simply avoid being near tall structures or buildings, again to avoid being struck by falling debris or objects. The message's philosophy is that earthquakes do not kill, it is only when people are exposed to danger during earthquakes that could potentially injure or kill them."