Menominee Crack (IMAGE) Michigan Technological University Caption The Menominee Crack split open ground in Michigan's UP. Caption: The Menominee Crack opened up in October 2010 and now researchers from Michigan Tech have determined it is a geologic pop-up structure. Credit Michigan Tech, Wayne Pennington Usage Restrictions please credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.