Magħlaq Fault, located along the southern coast of Malta (inset map) has experienced normal faulting. The southernmost part slid down relative to the northern part (white arrow).

A fault is a fracture in the earth’s crust where two sides have been displaced relative to each other. During an earthquake there is a rapid release of energy that has been stored around the fault, sometimes for many years or even centuries. This is similar to the energy stored in a compressed spring, which is then released. In a very large earthquake, such as that of Japan in 2011, this energy may be equivalent to thousands of nuclear bombs exploding together.

Usually, the bigger the earthquake, the larger the area of the fault. The movement on the fault can range from a few millimetres to a few metres.

Faults can be categorised into: normal , reverse, and strike slip. In normal faults, one block moves down relative to the other, while in reverse faults, the block moves up.

In strike slip faults, the two blocks move sideways.

Normal fault types are prevalent in Malta and are related to the island’s formation and development over millions of years. These faults formed the cliffs along the south coast of the Maltese islands, and also control the formation of escarpments, ridges and valleys crossing from west to east along the islands, such as the Victoria Lines, Mellieħa Ridge and the Comino and Gozo channels.