AKIPRESS.COM - When Italy was shaken by its fourth earthquake in a week early Thursday, the jolt was part of the country's most significant streak of seismic activity in a generation, reports USA Today.

Nearly 250 earthquakes strong enough to cause structural damage have hit Italy since the massive Aug. 24 quake that killed nearly 300 people in and around the town of Amatrice, according to Italy’s National Institute of Geophysics and Volcanology.

Those are earthquakes with a magnitude of at least 4.0, the lightest level that can cause structural damage.

Thursday’s magnitude-5.0 quake damaged dozens of buildings and monuments in central Italy. It was not nearly as severe as the magnitude-6.2 tremor near Amatrice in central Italy, or the magnitude-6.6 quake on Oct. 30, which was the strongest to hit Italy in 26 years.

The more recent series of earthquakes have leveled medieval villages, including numerous homes, churches, public buildings and monuments. And more damage may be on the way, according to the geophysics and volcanology institute’s Gianluca Valensise.

Valensise said one earthquake can weaken a nearby fault, making it rupture and causing a new earthquake. The resulting domino effect can last months or longer, particularly in an area like Italy’s Apennine Mountains, dense with fault lines and running down most of the Italian peninsula.

“This is probably what we have been experiencing since August,” Valensise said. “At least in theory, this process can continue indefinitely.”

It is nearly impossible to determine when an earthquake will strike or how long its aftershocks will last. That’s a lesson Italy learned the hard way: six Italian geologists and one civil servant were found guilty of manslaughter in 2009, after downplaying the risks of an earthquake six days before a deadly magnitude-6.3 earthquake flattened much of the city of L’Aquila, east of Rome. Their conviction was overturned only in 2014.

Improved building standards and evacuation plans have reduced the death tolls in recent years, but the impact is still devastating. Since August, more than 150,000 Italians have been forced from their homes by earthquakes and aftershocks. And countless historical and cultural riches have been destroyed or severely damaged.

“It’s heartbreaking. Part of our town died in that (Oct. 30) earthquake,” said Rosa Piermattei, mayor of San Severino Marche, a town of 12,000 with roots dating back to the Roman Empire. More than 500 buildings were damaged, and at least 1,500 residents were left homeless.

“We never experienced such a strong earthquake,” Piermattei said about her town, 120 miles northeast of Rome. “We’ve always been among those who rush to help when other towns are hit. This time it’s time for us to get the help.”

The last time Italy was so damaged by a series of earthquakes was in 1980, when a magnitude-6.9 quake and its aftershocks left 3,000 dead.