October 22, 2o23 — Offshore wind developers are encountering an unexpected challenge on the East Coast seafloor: a crushable, green mineral called glauconite, sometimes precisely where they plan to install wind turbines. The mineral — which dates back to the age of the dinosaurs — is weaker and less predictable than sand, scientists say, presenting a new engineering puzzle for researchers and wind developers to solve.
Glauconite’s behavior poses a “significant risk” to offshore wind development, said a paper published this year by the U.S. Bureau of Ocean Energy Management, the lead regulator of offshore wind. It said glauconite formations are “abundant” along the continental shelf, and that wind developers will “inevitably” encounter the material during construction.
At least two developers have run into the mineral in a total of three offshore wind projects — two south of Massachusetts and one south of Long Island, New York. In a document published last month, BOEM wrote that the geotechnical properties of the mineral make it an “extremely difficult material to build upon,” specifically for fixed-bottom wind turbines.
Glauconite’s presence has already caused BOEM to reject proposed wind turbine layouts that might have minimized a project’s potential effects on marine life and the fishing industry.