Miami Beach Buildings Sinking at Different Rates, Due to Construction, Study Finds

Much of the Miami Beach skyline, on ground that’s just a few feet above sea level, is sinking. But some of the iconic skyscrapers there are sinking at different rates and much of the subsidence is due to non-stop building construction on the barrier island, says a study led by professors from Florida and German universities.

“We attribute the observed subsidence to load-induced, prolonged creep deformation of the sandy layers within the limestone, which is accelerated, if not instigated, by construction activities,” reads the abstract for a study published in Earth and Space Science, a peer-reviewed academic journal.

The study, authored in part by University of Miami professors Farzaneh Aziz Zanjani and Falk Amelung, was published in late 2024. But it has suddenly gained widespread attention after new information was highlighted in recent news articles in the Miami Herald and other publications.

The authors of the study used satellite-based Interferometric Synthetic Aperture Radar, known as InSAR, to document the sink rate for 35 Miami Beach buildings over the last decade. The findings show that some structures have sunk into the ancient limestone and sand beneath them at a rate of about 2 centimeters from 2016 to 2023. But others, on Sunny Isles Beach and Surfside, have dropped more than 8 centimeters, or about three inches, raising new concerns for insurance underwriters and claims handlers.

The sinking structures include the famous, 60-story Porche Design Tower, which has seen many complaints from residents about cracking and leaking, and Trump Tower III, which is settling at almost a centimeter per year.

Some subsidence is expected for most skyscrapers, and it usually ceases shortly after construction, according to news reports. But the sink rate on parts of crowded Miami Beach barrier islands suggest the sink rate is worsening. More recent subsidence measurements correlate to construction-induced problems. It’s probable that differential rates of subsidence could lead to exacerbated structural issues and more insurance claims.

“There are no indications that subsidence will come to a stop,” the study concludes. “For structures subsiding at a constant rate this is obvious. For structures exhibiting a true exponential decay in subsidence, it could eventually cease. However, nearby construction vibrations are likely to restart the grain rearrangement process, leading to a renewed acceleration of subsidence.”

The study noted that Champlain Towers South, which collapsed in 2021, killing 98 people, showed no signs of subsidence before the disaster. Engineering reports have blamed the collapse mostly on deteriorated support columns at the 40-year-old condominium building.

But the recent subsidence study noted that the 87 Park tower adjacent to the Champlain Tower site is showing signs of sinking. And “subsidence of nearby low-rise buildings with relatively small structural loads … is almost certainly driven by construction activities,” the study concluded.

The Herald reported that it reached out to managers of all buildings cited in the study, but all declined to comment. The city of Sunny Isles Beach officials said last year that they had seen no reports of damage associated with settling.

The academic paper can be seen here.

Top photo: Sunny Isles Beach skyline (DepositPhotos)