Study finds dozens of buildings along South Florida coastline are sinking

The 7-year study found subsidence rates at 35 buildings ranging from 2 to 8 centimeters, with most effects recorded in communities such as Sunny Isles, Miami Beach, Bal Harbour and Surfside.

MIAMI - A new study led by experts at the University of Miami found dozens of buildings in South Florida that are settling into the ground, which could be a sign of erosion well beneath the surface.

The research, conducted between 2016 and 2023, found subsidence rates at 35 buildings ranging from 2 to 8 centimeters (about 1-3 inches), with most effects recorded in communities such as Sunny Isles, Miami Beach, Bal Harbour and Surfside.

Experts said they were able to come to their conclusions by examining hundreds of satellite images, which measured ground displacement over time.

"The discovery of the extent of subsidence hotspots along the South Florida coastline was unexpected," Farzaneh Aziz Zanjani, the study’s lead author, said in a statement. "The study underscores the need for ongoing monitoring and a deeper understanding of the long-term implications for these structures."

WHAT IS ‘DIRTY RAIN’ AND HOW DOES IT HAPPEN?

South Florida’s terrain is mainly composed of limestone interspersed with sandy layers, which can erode over time through Mother Nature and manmade sources.

According to the Florida Department of Environmental Protection, limestone is a sedimentary rock primarily composed of calcium carbonate, formed from the shells and skeletons of marine organisms.

The entire Florida peninsula is lined by limestone, but the presence of other materials such as clay, peat and rocks can reduce vulnerabilities with sinkholes and shifting.

Surfside tower collapse not linked to sinking

Researchers devoted special attention to Surfside, located about 5 miles north of Miami Beach, where a 12-story condominium complex collapsed in June 2021, killing 98 people.

Despite some claims that subsidence was one of the forces responsible for the collapse, researchers found no significant evidence that shifting of the ground played a significant role.

A full federal review is expected to be released in 2025, but investigators have narrowed in on construction flaws around the building’s pool as being responsible for its failure.

Researchers stressed the results of its study aren’t meant to scare property owners but lead to further investigations and monitoring.

"Our hope is that officials in Florida will recognize the value for continued research on this issue across the state and explore how this novel technology can benefit coastal residents." Falk Amelung, a professor of geophysics in the UM’s Department of Marine Geosciences at the Rosenstiel School, stated.

One of the communities highlighted by researchers released a statement following the report, stating: "The City of Sunny Isles Beach strictly adheres to these regulations, including compliance with the Florida Building Code and ongoing reinspection requirements. These measures are effective, and we remain confident in the safety of our residents."