Earthquakes in Eastern Europe are all part of the same 'cluster'

Earthquakes in Albania, Bosnia and Crete are all part of the same ‘cluster’, expert claims, as tremors rack parts of Eastern Europe

  • A 6.4 magnitude quake struck 50miles south of the Albanian capital Sarajevo
  • It hit the country on the 26th of November followed by dozens of aftershocks
  • Seismologists from the British Geological Survey say they can come in clusters 
  • So far in 2019 there have been 11,710 earthquakes over 4.0 magnitude worldwide

Recent earthquakes in Albania, Bosnia and Crete are all part of the same ‘cluster’ of quakes, according to an expert from the British Geological Survey (BGS). 

Albania was rattled by a 6.4-magnitude tremor in the early hours of Tuesday morning, and a series of aftershocks brought further misery later in the day.

The earthquake reduced buildings to ruins and sent people running into the streets in panic, some of them carrying babies – while tremors were felt across south-eastern Europe, including in North Macedonia and Bosnia. 

‘Earthquakes come in clusters or sequences which can make it seem like you get more over a short period of time’, said Dr Brian Baptie, a seismologist from the BGS.

Rescuers remove debris from a damaged building in Durres, western Albania, Wednesday, Nov. 27, 2019. Dozens are believed to have died as a result of the powerful earthquake in Albania (AP Photo/Visar Kryeziu)

Earthquakes are triggered by the movement of the planet’s tectonic plates as they rub and slide past each other. 

A large Earthquake can trigger a series of smaller quakes in the form of aftershocks, and even a bigger quake slightly later on the same fault line, says Dr Baptie. 

As well as the 6.5 magnitude quake, Albania was also battered by a series of aftershocks. There were 21 earthquakes strong enough to be felt in a period of 11 hours, experts said.

Dr Baptie says they come in a ‘cascade’ with smaller ones following one large quake.

‘In Italy in 2016 there were a series of smaller quakes after the 6.1 and 6.2 Earthquake followed by a larger 6.5 quake three months later.’

A map showing the location of the earthquake north of Durres, on the west coast of Albania

There have been 11,700 earthquakes measured so far in 2019 with the vast majority – more than 10,000 – at less than a 5.0 magnitude and only one over eight.

The magnitude of an earthquake also doesn’t necessarily have a direct link on death toll as that depends on where the earthquake epicentre is. 

In the case of the Albanian quake its epicentre around 50 miles south of the capital Sarajevo and so while the magnitude was 6.4 more people died than in the 8 magnitude quake in Peru in May where two people died. 

‘The number of six magnitude and above Earthquakes hasn’t increased, the clustering effect where secondary quakes are triggered by an initial, larger quake make it seem like there has been an increase,’ said Dr Baptie.

Rescuers search a damaged building in Durres, western Albania, Wednesday, Nov. 27, 2019 (AP Photo/Visar Kryeziu)

There was a spike after the 1950s but Dr Baptie says that is due to more sophisticated measuring equipment, rather than any increase in Earthquakes. 

Since the 1950s there has been an average of about 150 earthquakes above six magnitude each year but this could be up or down by 50 in any given year as the process can be random.

Earthquakes occur across the globe mainly in response to the stresses applied to the Earth’s surface as the planet’s dense tectonic plates slide across the weaker asthenosphere beneath.

They do not all not move in the same direction and often clash. This builds up a huge amount of pressure between the two plates.

Eventually, this pressure causes one plate to jolt either under or over the other.

Rescuers search a damaged building in Durres, western Albania, Wednesday, Nov. 27, 2019 (AP Photo/Visar Kryeziu)

This releases a huge amount of energy, creating tremors and destruction to any property or infrastructure nearby.

Severe earthquakes normally occur over fault lines where tectonic plates meet, but minor tremors – which still register on the Richter sale – can happen in the middle of these plates.

Dr Baptie said for there to be a notable change in the number of Earthquakes there would need to be a significant change in the processes that power the Earth and ‘there are no signs of any change happening’.

He said there is one exception to the rule that the average number of Earthquakes over time won’t change – man made quakes.

The United States of America has been depositing waste water into the ground which has let to an increase in the number of man made Earthquakes, but there has been no increase in naturally occurring faults. 


Earthquakes are detected by tracking the size, or magnitude, and intensity of the shock waves they produce, known as seismic waves.

The magnitude of an earthquake differs from its intensity.

The magnitude of an earthquake refers to the measurement of energy released where the earthquake originated.

Magnitude is calculated based on measurements on seismographs.

The intensity of an earthquake refers to how strong the shaking that is produced by the sensation is.

A 5.3 magnitude earthquake hit the Channel Islands off the coast of southern California on Thursday at 10.30am

According to the United States Geological Survey, ‘intensity is determined from the effects on people, human structures and the natural environment’.

Earthquakes originate below the surface of the earth in a region called the hypocenter. 

During an earthquake, one part of a seismograph remains stationary and one part moves with the earth’s surface.

The earthquake is then measured by the difference in the positions of the still and moving parts of the seismograph. 

Source: Read Full Article