Imaging the Underground: Investigating Mystery Cave using Geophysics
Presenter(s)
Catheryn Hudak, Ben Earley, Ian McKinzie
Abstract
Subsurface conditions are essential for understanding groundwater flow, geological structure, and cave formation processes. Mystery Cave, located in southeastern Minnesota, is the longest cave in the state, containing over 13 miles of underground passages within a karst landscape, a landscape that has numerous caves in the subsurface. These systems contain soluble bedrock such as limestone and dolostone, which create a network of complex underground fractures and tunnels. In GEOS 442 Geophysics last semester (Fall 2025), our class used an Electrical Resistivity Imaging (ERI) system that pushes electric current into the ground and measures the ease at which the current passes through the subsurface. GEOS 442 students used the ERI system in November 2025 at Mystery Cave State Park and collected data to interpret characteristics of the subsurface. Resistivity depends on the amount of water in the subsurface and can illuminate the difference between soil and bedrock. These data are used to infer the structure and composition of the underlying subsurface and better understand the geological features under the surface. Examining resistivity patterns in this study gives insight into the subsurface conditions that influence the formation and development of Mystery Cave. Our results will be used by State Park naturalists to better understand the cave system.
College
College of Science & Engineering
Department
Geoscience
Campus
Winona
First Advisor/Mentor
Jennifer Anderson
Location
Kryzsko Great River Ballroom, Winona, Minnesota; United States
Start Date
4-23-2026 10:00 AM
End Date
4-23-2026 11:00 AM
Presentation Type
Poster Session
Format of Presentation or Performance
In-Person
Session
1b=10am-11am
Poster Number
20
Imaging the Underground: Investigating Mystery Cave using Geophysics
Kryzsko Great River Ballroom, Winona, Minnesota; United States
Subsurface conditions are essential for understanding groundwater flow, geological structure, and cave formation processes. Mystery Cave, located in southeastern Minnesota, is the longest cave in the state, containing over 13 miles of underground passages within a karst landscape, a landscape that has numerous caves in the subsurface. These systems contain soluble bedrock such as limestone and dolostone, which create a network of complex underground fractures and tunnels. In GEOS 442 Geophysics last semester (Fall 2025), our class used an Electrical Resistivity Imaging (ERI) system that pushes electric current into the ground and measures the ease at which the current passes through the subsurface. GEOS 442 students used the ERI system in November 2025 at Mystery Cave State Park and collected data to interpret characteristics of the subsurface. Resistivity depends on the amount of water in the subsurface and can illuminate the difference between soil and bedrock. These data are used to infer the structure and composition of the underlying subsurface and better understand the geological features under the surface. Examining resistivity patterns in this study gives insight into the subsurface conditions that influence the formation and development of Mystery Cave. Our results will be used by State Park naturalists to better understand the cave system.
Comments
Hudak, Catheryn E; McKinzie, Ian D; Earley, Ben P