The mystery behind what caused a unique crack in the ground of Menominee, Michigan, five years ago in October 2010 has been cracked. Faculty and student researchers from Michigan Technological University, on studying the area for long, concluded that the pop-up occurred due to release of underground pressure on the limestone rock in the area.

The residents of the area experienced around 15 seconds of unusual movements, they thought that it was an earthquake, but scientists believed that it wasn’t an earthquake as it didn't register on a seismograph. Rather the movement was caused by something else.

The areas of Upper Peninsula rarely receive earthquakes. The 360-foot-long crack on Heider's property was discovered when in morning some workers were sent into the woods to clean up the leftover debris from a fallen large pine tree due to shock. The crack stretches over 110 meters and in some places was as deep as 1.7 meters. The team of scientists from the Michigan Technological University found the ridge as the most interesting part of the formation.

The Michigan Technological researchers have discovered that the pop-up resembles the formation that occurs at the base of quarries where glaciers have recently receded, but the crack site in Michigan had glacier even before 11,000 years ago.

“So why did it wait until 2010 to happen? All the stress in that area has been relieved. If it was waiting 11,000 years for the final trigger, there's not a lot more stress there waiting to happen”, said Wayne Pennington, a geophysicist who's the dean of Michigan Tech's College of Engineering. So they could not really say that it happened due to removal of ice caps. Pennington even assure the local residents that such formation is unlikely to occur in future.