Before condo collapse, rising seas have long pressured Miami coastal properties
The 12-story condo tower that crashed down early Thursday near Miami Beach was built on reclaimed wetlands and is perched on a barrier island facing an ocean that has risen about a foot in the past century due to climate change.
Underneath its foundation, as with Miami Beach, is sand and organic fill —over a plateau of porous limestone — brought in from the bay after the mangroves were deforested. The fill sinks naturally and the subsidence worsens as the water table rises.
Investigators are just beginning to try to unravel what caused the Champlain Towers South to collapse into a heap of rubble and leave 99 people missing. Experts on sea level rise and climate change caution that it is too soon to speculate if rising seas helped destabilize the oceanfront condo. The 40-year-old building was relatively new compared with others on its stretch of beach in the town of Surfside.
But it’s already clear that South Florida has been on the front lines of sea level rise and that the impacts of climate change on the infrastructure of the region — from septic systems to aquifers to shoreline erosion — will be a management problem for years to come.
The Champlain Towers South building was recently found to have been sinking in the 1990s and may have continued to sink since then, according to Shimon Wdowinski, a professor at Florida International University’s department of earth and environment, who has studied the area.
Wdowinski co-wrote a paper published in April 2020 that said satellite imagery showed a 12-story condominium building in the eastern part of the Miami Beach area had sunk by about two millimeters per year between 1993 and 1999. Wdowinski said in an interview on Thursday that this was the Champlain Towers South building. [Continue reading…]