On the day of the horrific condo tower collapse in Surfside, Fla., we briefly noted Shimon Wdowinski, a professor in the Department of Earth and Environment at Florida International University, completed a recent study on the condo building and found it had sunk. The study also revealed other areas in Miami where land was unstable as the federal government declared Friday afternoon it would launch an investigation.
Wdowinski's study, titled "Local land subsidence in Miami Beach (FL) and Norfolk (VA) and its contribution to flooding hazard in coastal communities along the U.S. Atlantic coast" was co-authored by Simone Fiaschi and published on ScienceDirect, revealed the Champlain Towers South condo complex "had some kind of unusual movement" and was sinking 2 millimeters a year in the 1990s.
According to USA Today, Wdowinski and Fiaschi did not alert Surfside city officials about the sinking issue, nor was anyone in the city government alarmed or even bothered examining the study because it focused primarily on flooding hazards, not engineering disasters due to sinking land.
"Wdownski said he doesn't believe anybody in the city or state government would have had a reason to be aware of the findings of the study. The bulk of it focused on potential flooding hazards, not engineering concerns."
Researchers used Interferometric Synthetic Aperture Radar, or InSAR, with data that spanned from 1992–1999 and found the Champlain Towers South condo complex was sinking into the Earth.
"In some locations, as in the eastern part of the city, the detected subsidence is of a 12-story high condominium building (northernmost black circle in Fig. 3A). The detected subsidence rate is in the 1–3 mm/yr range, with an uncertainty level of 0.6–0.8 mm/yr....