Sinkholes Threaten to Swallow Naples’ Historic Churches, Study Suggests

A new paper identifies 9 high-risk places of worship and 57 that are susceptible to “potential future cavity collapses”

Basilica di San Francesco di Paola
The Basilica di San Francesco di Paola is one of nine Naples churches in areas deemed highly susceptible to sudden collapse. Mister No via Wikimedia Commons under CC BY 3.0

Since 1890, more than 70 sinkholes have opened up in Naples’ historic city center, swallowing everything from vehicles to street signs and trees. Now, reports Garry Shaw for the Art Newspaper, a new study suggests that dozens of churches in the Italian city are at risk of collapsing into similar subterranean cavities.

As detailed in the Journal of Cultural Heritage, researchers from the University of Naples Federico II drew on satellite images, previous studies and maps to identify 9 houses of worship in critical danger of sinkhole-related damage and 57 that are susceptible to “potential future cavity collapses.” Per the paper, the nine high-risk sites “require a quick response in terms of characterization, stability analysis and real time monitoring.”

Naples is home to more than 500 places of worship spanning 2,400 years of history; according to the Art Newspaper, many of these buildings “stand over an extensive network of underground spaces”—or cavities—alternatively used as cemeteries, catacombs, cisterns, aqueducts and quarries.

Of the at least 190 sinkholes recorded in the broader Naples metropolis between 187o and 2010, the study’s authors note that around 25 percent occurred as a result of sudden cavity collapses triggered by human activity, rainfall and other external factors. The findings place the risks faced by such high-concern churches as the Basilica di San Francesco di Paola, the Chiostro dei Miracoli and the Chiesa della Nunziatella in stark terms.

Hundreds evacuated from homes as huge sinkhole appears in Naples

Naples’ religious centers are no stranger to sinkholes. In 2009, a cavernous, more than 16-foot-deep hole opened up beneath San Carlo alle Mortelle, a 17th-century church known for its Baroque art. The house of worship reopened in 2017 after undergoing roughly $1.78 million worth of repairs, reported at the time.

Though sinkholes pose an evident threat to Naples’ cultural and religious heritage, the southern Italian city remains in a relatively better position than its northern neighbor Rome. Last year, reports the Local Italy, 100 sinkholes opened up in Rome, versus around 20 in Naples.

Much like in Naples, “[t]he main cause of a sinkhole in [Rome] is the presence of an underground cavity,” geologist Stefania Nisio told Adnkronos’ Stefania Marignetti in January, per a translation by the Local Italy. The fact that Rome is built atop of easily eroded sandy soil exacerbates the problem.

Sinkholes aren’t simply arbiters of destruction: They can also expose unexpected gems. In April, a sinkhole that opened up in Rome just outside of the Pantheon revealed seven slabs of imperial pavestones, per Agenzia Nazionale Stampa Associata (ANSA). Researchers dated the travertine rocks to between 27 and 25 B.C.

Fortunately for Naples, the European Union is funding a project to redevelop the city’s historic center—a campaign that should help save churches from sinkholes. As the Art Newspaper reports, a number of churches—including the 17th-century Santi Cosma e Damiano ai Banchi Nuovi—have reopened as a result of the project.

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