Did you feel the earth shake?

Probably not in the past 24 hours, yet many would be surprised to learn that a total of ten earthquakes were reported in or near Gibraltar during a 24-hour period on May 6.

Of these ten quakes, just two were above magnitude 3, which may have been slightly felt by some people.

The other eight were of magnitude 2 or less — little more than a tremble, as if the Earth had momentarily shivered.

The word “earthquake”, or “quake” for short, often brings images of catastrophe and major disasters, mainly due to a lack of understanding about tectonic movement.

No matter how often it is explained that there are major differences in the power released at each magnitude level, many still picture panic, collapsing buildings, the ground opening up, or similar scenes of destruction. However, there is a vast difference between a magnitude 2 and a magnitude 3, let alone between a 2 and a 6 or 8. The latter magnitudes are far more likely to cause serious damage, depending also on the depth and location of the epicentre.

A magnitude 6 earthquake releases vastly more energy than a magnitude 2. In fact, because the magnitude scale is logarithmic, a magnitude 6 releases about 10,000 times more energy than a magnitude 2. You could compare it to the difference between being lightly poked with a finger and being forcefully shoved by a squad of rugby players all at once.

Nevertheless, this does not stop the occasional doomsday reactions and panic whenever even a magnitude 2 quake is recorded.

Gibraltar, located close to the boundary between the African and Eurasian tectonic plates, experiences continuous seismic movement and minor tremors.

The data shows that, during the past decade alone, more than 500 quakes have been recorded in and around Gibraltar. The figure would be considerably higher if the wider Alboran Sea region were included. After all, the African tectonic plate is slowly moving towards the Eurasian plate, a process that over millions of years continues to shape the landscape of the region.

The good news is that, of the more than 500 quakes recorded during the past decade, only three have reached magnitude 4.

Nevertheless, earthquakes must still be treated with the appropriate caution. They are reminders that the Earth is constantly moving and is far less silent, solid, and static than it may appear.

Each quake is also a reminder that significant earthquakes have occurred in this region in the past and will eventually occur again. Exactly when this might happen cannot currently be predicted with precision.

So when someone asks, “Did you feel the Earth move?”, perhaps the better question is: did it move without you even noticing?