Thunder Bay Exploration 2002

Shipwreck Mapping Results from 2001

In June 2001, the Institute for Exploration (IFE) and the Thunder Bay National Marine Sanctuary and Underwater Preserve used sidescan sonar technology to survey the deepwater shipwrecks of the Sanctuary. The expedition team used IFE's new sidescan sonar towfish, called ECHO, which uses sound to image objects on the lakebottom. Working 24 hours a day for 14 days, the expedition team covered 342 square miles of Lake Huron lakebottom. Within this area, the team located approximately 70 "targets," anomalies in the sonar data that could be intact shipwrecks, parts of shipwrecks, rock outcroppings, boulders, or unidentified obstructions. Of these targets, 11 are known shipwrecks and three are shipwrecks whose identities are not known to the expedition team.

In addition to mapping shipwrecks, the expedition team located geologic features known as "karsts." Karsts are limestone formations that have undergone dissolution during lower lake levels, producing a terrain with dozens of sinkholes.