MARQUETTE, MI— Residents shouldn’t be concerned if they see low-level airplane flights across the Upper Peninsula and northeastern Wisconsin starting this month.
The U.S. Geological Survey is conducting surveys of mineral resources across most of the U.P. and parts of Wisconsin using technology that functions like an MRI. The USGS says it’s part of a national effort to map critical mineral resources needed to drive the U.S. economy and national security, searching below ground and in tailings from old mines.
The 300-foot-elevation flights will cover areas within Alger, Baraga, Chippewa, Delta, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Luce, Mackinac, Marquette, Ontonagon, and Schoolcraft Counties in Michigan, as well as Ashland, Florence, Forest, Iron, Marinette, Price, and Vilas Counties in Wisconsin.
The magnetic component of the survey detects variations in the Earth’s magnetic field that reveal subsurface structures up to a few kilometers deep, or about 10,000 feet. Radiometric sensors measure natural low-level radiation to help map the distribution of potassium, thorium, and uranium near the surface.
The survey will use aircraft equipped with an elongated “stinger” mounted to the tail extending backward off the aircraft. The scientific instruments on the aircraft are completely passive, with no emissions that pose a risk to humans, animals, or plant life. No photography or video data will be collected.
Most of the surveying is expected to be completed by the late autumn of 2025; however, surveying may continue in the spring and summer of 2026 to avoid adverse weather conditions.
