A recent study reveals that around 35 high-rise condominiums and luxury hotels along South Florida's coastline are experiencing unexpected sinking or settling, partly due to nearby construction.

The survey, conducted over a nearly 12-mile (19-kilometer) stretch from Miami Beach to Sunny Isles Beach, found these buildings had subsided between 0.8 and 3.1 inches (2 to 8 centimeters). Researchers from the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science noted that nearly half of these buildings were built within the last decade.

Lead researcher Farzaneh Aziz Zanjani stated that the scale of these “subsidence hotspots” along the South Florida coast was unforeseen. The findings highlight the importance of continued monitoring and deeper investigation into the long-term impacts on these structures.

While some settling is normal during or shortly after construction, the researchers were surprised by shifts occurring years later. The area’s geological makeup, consisting of limestone interspersed with sand layers, makes it vulnerable to subsidence under the weight of buildings and vibrations from construction activities. Additional factors, such as tidal flows and construction up to 1,050 feet (320 meters) away, also contributed to the settling, with the most significant changes observed in Sunny Isles Beach. Preliminary data suggests similar issues further north in Broward and Palm Beach counties.

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The study area included Surfside, the site of the catastrophic 2021 Champlain Towers South collapse that killed 98 people. While that tragedy was primarily attributed to poorly maintained reinforced concrete and design flaws, it underscored the critical need for monitoring building stability in corrosive coastal environments.

The researchers plan to investigate whether different parts of the affected buildings are sinking at varying rates, which could lead to structural damage such as cracks and utility disruptions over time.

Separately, earlier research from Virginia Tech and the U.S. Geological Survey found that cities along the Atlantic Coast, including New York City, Long Island, Baltimore, and Virginia Beach, are also sinking at rates exceeding sea-level rise.