The area where a building partially collapsed in Surfside, Fla. showed signs of land subsidence in the 1990s, according to space-based radar data analyzed by an FIU professor.
The 2020 land and sea level rise study conducted by FIU Institute of Environment Professor Shimon Wdowinski identified the 12-story Champlain Towers South condominium as the one place on the east side of the barrier island where land subsidence was detected from 1993 to 1999. But land subsidence in and of itself likely would not cause a building’s collapse, according to Wdowinski, an expert in space geodesy, natural hazards and sea level rise.
“When we measure subsidence or when we see movement of the buildings, it’s worth checking why it happens,” Wdowinski said. “We cannot say what is the reason for that from the satellite images but we can say there was movement here.”
Western Miami Beach saw subsidence over larger areas but that was expected because homes there are built on reclaimed wetland. Areas where land is subsiding are more likely to experience more serious effects of sea level rise, according to the study.
In the 1990s, Miami Beach experienced subsidence at the rate of 1-3 millimeters per year, which could add up to a few inches of movement over a decade, Wdowinski said. It was significantly slower compared to other parts of the planet Wdowinski has studied. Mexico City, for example, is subsiding at a rate of 15 inches per year.
The researcher believes the same technology he used to detect land subsidence could be used to detect vulnerable buildings and help prevent future catastrophes.
The study was published in the journal Ocean & Coastal Management.