(Photos Courtesy of Indiana Dunes National Lakeshore)
Mt. Baldy will remain closed this summer as scientists continue their investigation. Officials with the Indiana Dunes National Lakeshore today announced despite the use of ground penetrating radar and data gathering, scientists still do not know the cause of the holes at Mt. Baldy. Additional research will be conducted this summer and may continue into the fall, so to ensure the public's safety, Mt. Baldy, its parking lot, trail and the beach in front of the dune will remain closed to all vehicular and pedestrian access while the investigation continues.
Ground penetrating radar studies by the Environmental Protection Agency (EPA), have identified a large number of anomalies below the dune’s surface, but analysis by scientists from the National Park Service, Indiana University and the Indiana Geological Survey have not yielded answers on how these holes form. One such hole nearly cost a 6-year old Illinois boy his life last summer at the national lakeshore’s most popular sand dune.
The two additional holes and a number of depressions have been found during the ongoing investigation and continued monitoring of the dune. Scientists report that the holes are short-lived, remaining open for less than 24 hours before collapsing and filling in naturally with surrounding sand.
Scientists are now preparing for a more comprehensive investigation of the dune this summer. This study will include mapping of openings, depressions, and anomalous features, the use of multispectral Ground-Penetrating Radar (GPR) and coring to develop a better understanding of the overall internal architecture of the dune, and detailed GPR and coring of some of the anomalies identified in the EPA report.
During the research work, the park’s resource managers will continue planting marram grass on portions of Mt. Baldy where the native dune grass used to grow. The extensive root system of the grass holds sand in place and may also help prevent holes from opening up on the dune’s surface.
All other beach access areas within the national lakeshore are currently open and visitors are asked to stay on the established trails to prevent erosion and subsequent resource damage.
For more information, and to view the EPA’s Geophysical Survey Report, a Core Study, photos, video, and graphics on the Mount Baldy research, go to the national lakeshore’s website at: www.nps.gov/indu.