How were the sinkholes discovered?
During a 2001 Lake Huron Thunder Bay National Marine Sanctuary survey, Dr. Dwight Coleman (Institute for Exploration) first discovered a series of offshore freshwater underwater sinkholes at a depth of approximately 100 meters, formed by a unique series of environmental processes. Sinkholes on land and in shallow nearshore areas have been known to local residents for some time; however the unique ecosystems represented in these systems have not been studied. Lake Huron experienced a period of low levels between 10,000 and 6,000 years ago, exposing its limestone bedrock to erosion by groundwater. Sinkhole formation began as acidic water dissolved away passages and holes in the limestone rock, resulting in weak ceiling structures prone to collapse. Why are sinkholes of interest to NOAA? An understanding of these systems is important to NOAA in determining the groundwater volume these systems may contribute to Lake Huron lake levels (important to Great Lakes shipping), unraveling the myst
