A study has raised alarms about thirty buildings on Florida's southern coast: They are sinking

A recent study from the University of Miami (UM) has revealed that 35 coastal buildings between Miami Beach and Sunny Isles Beach are sinking at a rate of between 2 and 8 centimeters in recent years.

The research was led by scientists from the Rosenstiel School of Marine, Atmospheric, and Earth Sciences at UM and was published in the journal Earth and Space Science.

Findings of the study

The study, which used satellite radar to measure displacement, analyzed the period from 2016 to 2023.

The scientists monitored fixed elements of the buildings, such as balconies, rooftop air conditioning units, and walkways.

Satellite technology enables the detection of "shifts on the scale of millimeters," facilitating a precise analysis of the phenomenon.

The buildings in Sunny Isles Beach recorded the most significant subsidence, followed by those in Surfside.

The latter was the site of the tragic collapse of the Champlain Towers South apartment building in 2021, which resulted in nearly 100 fatalities.

The study clarifies that no signs of displacement were detected in Surfside prior to the collapse, suggesting that the sinking was not the cause of the collapse.

"The discovery of the extent of sinking areas along the southern Florida coastline was unexpected. The study highlights the need for constant monitoring and a deeper understanding of the long-term implications for these structures," noted Farzaneh Aziz Zanjani, who led the research.

Professor Gregor Eberli, co-author of the study, emphasized:

"The sinking, officially known as subsidence, is not exclusive to South Florida. For instance, New Orleans, Mexico City, and Venice are classic cases where entire cities are sinking. Compared to these examples, this is relatively minor."

Causes of the phenomenon

The study attributes the sinking to several factors, including: the displacement of grains in the sand layers due to the weight of buildings and construction vibrations, daily tidal flows, and the potential fracturing of the limestone beneath the surface.

Eberli noted that the limestone in Florida is generally stable, but clarified that the sand tends to compact over time.

"The sand portions will always compact slightly over time. It is a very slow process, and the structural integrity will not be compromised by a little settling," he explained.

However, he emphasized that the stability of the ground varies: “The tougher limestone in the southern part of the research area does a better job of supporting heavy buildings than the softer terrain to the north.”

Impact and reactions

The study arises in the context of the Champlain Towers South tragedy, which has prompted increased scrutiny of infrastructure in South Florida.

Although the collapse was not related to subsidence, researchers warned that vibrations caused by nearby constructions in Surfside did lead to sinking in other buildings.

The mayor of Surfside, Charles Burkett, expressed his concern and stated that he will present the study at the next municipal commission meeting.

For his part, Eberli emphasized that while there is no cause for alarm, the study should encourage ongoing monitoring efforts.

"The study should lead to more monitoring efforts and other forms of research. I wasn't surprised it happened, but the rates aren't that significant," he concluded.

Although the data does not pose an immediate threat, experts emphasize the need for constant monitoring measures to ensure the safety and stability of these structures in the future.

Frequently Asked Questions about the Sinking of Buildings on Florida's South Coast