Last month’s seismicty in the Mediterranean region was marked by a strong earthquake off the coast of western Greece, beneath Cephalonia island, on January 26 (largest yellow circle on map). The magnitude 6.1 earthquake struck at 3.55pm local time and caused minor damage and injuries.
The shaking was also felt in Malta, with a number of people reporting their experience through the online questionnaire on the University’s Seismic Monitoring and Research Unit (SMRU) website http://seismic.research.um.edu.mt .
This earthquake was followed by a series of aftershocks throughout the last week of January.
Two minor earthquakes of magnitude 2 struck close to Malta on January 16 and 17, 12 kilometers off Marsaxlokk (red stars, inset map). The SMRU received no reports of the quake having been felt.
Earthquake aftershocks
Aftershocks are earthquakes that take place after a (large) major earthquake at approximately the same location. They have a lesser magnitude. Physically there is no difference between a ‘normal’ earthquake and an aftershock.
Aftershocks occur because the plates that would have moved and created the main shock need to settle down. These shocks can be felt for days, months and sometimes even years, depending on how large the main shock was.
Although aftershocks are not as strong as the main shock, they can be dangerous, especially because buildings that have already been damaged in the main shock may collapse. By monitoring the location of the aftershocks, seismologists can determine better the area that slipped during the main shock.
Following the magnitude 6.1 earthquake in Greece last month, over 550 aftershocks were recorded within a span of six days, all located approximately in the same area, beneath Cephalonia island. The series of aftershocks is not over yet and is expected to continue throughout February.