Q&A Of The Day – What Other South Florida Locations Are Sinking? Part 1
Each day I feature a listener question sent by one of these methods.
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Today’s entry: @brianmuddradio great interview today with FIU professor but I missed a KEY question: Which other properties were studied and found sinking?
Bottom Line: It’s extremely important to note, before addressing further, that the cause of the collapse hasn’t been determined though is increasingly looking like structural failure which had been many years in the making based a 2018 engineering report on the Champlain Towers South building released by Surfside as rescue and recovery efforts continued through the weekend. In the report there were several concerning items, most notably this excerpt: The failed waterproofing is causing major structural damage to the concrete structural slab below these areas. Failure to replace the waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially. That was three years ago and pretty well speaks for itself at this point. Before addressing what the FIU study found back in the 90’s, it’s important to note – as the researcher who led that study has, that the gradual subsiding alone wouldn’t have caused what we witnessed. As the 2018 engineering report identified – the building wasn’t at imminent risk of failure but clearly not addressing the issues cited had the potential to be catastrophic. On that note, to address your question...
The widely cited FIU study of the Champlain Towers South site was led by FIU’s Earth and Environment expert Dr. Shimon Wdowinski and was co-authored by the University of Padova’s Earth Sciences professor Dr. Simone Fiaschi. Though the research began in 1993, the study, referred to as 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 notably just published last year in the journal Ocean and Coastal Management. The findings specific to the Champlain Towers South site itself was a subsiding at the site of 1.9mm annually between 1993 and 1999. When backed up with the 2018 engineering report on the building – it's certainly possible the sinking was connected to “major structural damage”.
To the root of your question what other sites were observed in 2020 study? Broadly the study showed Miami Beach subsiding at the rate of 1-3mm annually during same window in the 90’s. As FIU notes, that’s low compared to other monitored locations globally. Mexico City, which sits 7,200 feet above sea level, at a remarkable 15 inches per year! Context is key in having this conversation – there are so many variables that can come into play which is why it’s critical to let the expert investigators do their work and put all of the pieces together. I’ll pick up there in the second part of today’s Q&A along with the other specific sites monitored in the FIU study.