08/09/2018

The Birth of Seismic Design : Ferrara Italy 1570

By Anthony Zampolin

Sunday November 16th 1570

9:30am – The first strong earthquake strikes outside of the city, 600 pieces of stone masonry are documented to have fallen from the perimeter battlements.

The day is hampered with light tremors and small aftershocks

8:00pm – The second strong quake hits the whole of Ferrara, most of the unsupported walls begin to collapse.

Monday November 17th 1570

3:00am – The third, strongest shock hits the city. All previously affected structures with collapsed walls are demolished. All public buildings have been destroyed including most of the city’s Duomo structure.

November 17th 1570 – 1574

Seismic events; beginning with the major disasters from November 16th to the 17th, terrorized the city of Ferrara for the next 4 years with over 2,000 tremors recorded. 

It was the stance of the Holy See (during the time) that earthquakes ravaged the area because the local government did not do enough to persecute people of a certain religion; an ideal of the time that natural disasters were acts of God sending judgement down to earth.

Following the initial earthquakes in November, the relief effort community set up tents where people of the city began to rebuild and rethink their lives during the twilight of the renaissance.

In an essay written by Emanuela Guidaboni and Marco Folin: "it was a place where people from all social levels found themselves living side by side for months at a time, in a state of promiscuity that even involved the ruling family and their entourage. The image of the Duke’s Court transferred to provisional tents profoundly impressed the imagination of the people, creating an extraordinary amount and variety of sources of information: diaries and eyewitness accounts, several treaties aimed at investigating the causes of the event, even sonnets and poetry were composed".

Cover for "Of The Earthquake, a dialogue by Mr. Lucio Maggio, a gentleman from Bologna" an interview highlighting the experience of a nobleman from Bologna entering Ferrara and assessing the damage.

Needing answers to why his city was turned to rubble, the Duke of Ferrara Alfonso II d’Este created a group lead with architect, painter, and antiquarian Pirro Ligorio. Like many renaissance men of the time, Pirro approached unanswered questions scientifically. With such a long span of seismic events taking place in Ferrara, he decided to document quakes as they took place. By seeking out information of other earthquakes around the world, he created a time-line documenting their intensity. Thanks to his meticulous details recording the damage that the quakes had caused the city, he changed the way people viewed the events as no longer being a mystical consequence but a common act of nature. 

Drawing of Pirro Ligorio

As successor to Michelangelo at the Vatican Workshop, Pirro founded what would be known today as the first seismic observatory for earthquakes around the world. The work he led produced masterpieces of the time outlining hypotheses on the causes and effects of earthquakes. This included first known rational investigations on if earthquakes can be detected or prevented, and most importantly harsh criticisms for the methods of construction in areas prone to these natural disasters. In his research he found that the inconsistency of concrete mixtures was the main cause for structural failure, placing the blame for major damage on masons and builders.

Pirro's anti-seismic architectural drawings

Pirro created the first documented anti-seismic designs for safer structures. His over-scrutinization of building materials and structural organization to prevent damage caused by earthquakes paved the way for our present day knowledge of seismic design.