The earthquake that rocked Durban and surrounding areas serves as a timely reminder that seismic activity can erupt without warning. Undersea tremors near coastal areas could also serve as a catalyst to trigger off quakes on land.
An earthquake of 6m, which rocked Nepa in the USA, originated on a fault line that was inactive for over a hundred thousand years.
Most earthquakes result from plate tectonics, the continuous movement of immense plates of land along the earth’s surface. Scientists know where these fault lines are, and have maps of where earthquakes are most likely to happen. But they cannot predict with certainty when a large earthquake will occur.
Scientists have had some degree of success in forecasting earthquakes. Northridge earthquake in the U.S.A was predicted by ultra long wave radio anomalies.
An Italian earthquake was predicted by ground radon excretion. In Croatia they predict via a sudden miscorrelation between the three magnet field orientation readings.
The Demeter satellite has recently detected night time ion increases over earthquake epicentres before they happen within 14 days. Infrared detection of fault heating has also been used to detect specific faults under increasing stress that break within 7 to 30 days.
The problems of earthquake prediction research were approached through a compilation of a succession of isolated case histories of presumed precursors to subsequent large and small earthquakes.
The scientific challenge to predict earthquakes will elude us for another century.