During the past year, sinkhole collapses headlined newspapers around the globe. From Kentucky to Guatemala, these catastrophic events attracted much attention and provided an opportunity for researchers to continue studying the causes, impacts, and remediation of sinkholes. These occur naturally when the ground surface collapses into voids in the rock below, and can be found across a large portion of the world. Yet these common features are often unknown to people who live in areas prone to sinkholes. For those who are aware, sinkholes often are used as garbage dumps and natural water drains, or completely ignored with respect to being potential environmental hazards. At WKU, dealing with sinkholes is a common activity as we are located within the karst landscapes of southcentral Kentucky. In this region, despite being prevalent, most sinkholes are not dangerous or pose little threat to life or property.
Feb. 12, 2015, marked the one-year anniversary of the major sinkhole collapse at the National Corvette Museum in Bowling Green. Throughout the past year, media coverage continued to focus on this story and generated much interest in the evolution of the sinkhole from its collapse to the current remediation underway. In November, Dr. Leslie North and Dr. Jason Polk of the Department of Geography and Geology and WKU’s Center for Water Resource Studies appeared in a Weather Channel documentary about sinkholes and caves. The TWC Secrets of the Earth series focuses on scientific issues and natural phenomena on Earth. Both Dr. Polk and Dr. North provided consultation on the program’s content, which discusses karst landscapes in depth and provides visuals on how caves, groundwater, and sinkholes form a natural system. These systems collectively can create geohazards in many locations around the world.
Additional featured guests in the documentary included Randy Orndorff of the United States Geological Survey, Dr. Tom Aley of Ozark Underground Labs and Dr. Doug Gouzie of Missouri State University. Collectively, the group has vast expertise in cave and karst processes and sinkhole formation, thereby providing rich content for the documentary, which is meant to educate the public about the seemingly mysterious ways in which these potentially deadly landforms occur all around the world.
The documentary highlights sinkholes from around the world, including the recent Florida collapse where a man died, the deep sinkhole in Guatemala City, and the National Corvette Museum sinkhole. Dr. Polk and Dr. North focused primarily on the National Corvette Museum sinkhole that occurred in February 2014 and swallowed eight rare Corvettes on display in the Skydome portion of the building.
The day before the Secrets of the Earth premiere, on Nov. 9, Dr. Polk and his WKU colleagues Dr. Pat Kambesis and staff member Kegan McClanahan entered the Corvette Museum sinkhole one final time to complete their mapping, data collection, and photo and video documentation of the cave and sinkhole collapse before the construction crews began work to fill the hole. Since then, construction crews have worked to stabilize and fill the sinkhole. Currently, there is little remaining evidence of the gaping hole that once dominated the Skydome’s floor. Work is underway to repair the floor and stabilize it with micropiles to prevent any further risk of collapse.
“The documentary by TWC does an excellent job of incorporating the science of sinkholes and using visuals and common terms to explain their formation,” Dr. Polk said. “In addition, the production team was great to work with and researched their facts well to include the use and definition of the term ‘karst’ and maintain accuracy about the profiled sinkholes.”
Many areas of the southeastern United States have limestone bedrock that dominates the geology. This type of rock can easily form caves, sinkholes, and large aquifer systems when it is slowly dissolved by rainwater that becomes slightly acidic from carbon dioxide in the air and soil. Natural sinkhole occurrences are exacerbated by changes in rainfall, groundwater usage, and human impacts, such as urbanization and agriculture. These sinkhole- and cave-riddled landscapes are known as karst regions. Karst landscapes are of profound importance because they supply over 25 percent of the world’s drinking water. This supply comes from groundwater flowing in voids and cavities in the rock, which creates large aquifer systems and beautiful, blue springs that sometimes emerge from the ground.
Dr. Polk and Dr. North are working with the National Corvette Museum and Creative Arts Unlimited of Pinellas Park, Florida, to develop a unique, cutting-edge educational exhibit about the sinkhole and its repair to help in educating the general public. “The Museum has done an excellent job of turning this unexpected, negative event into a learning opportunity by embracing the public’s curiosity and providing information and knowledge about the sinkhole throughout the whole process. I am excited to work with the Museum to create a stellar interactive exhibit that furthers efforts to educate the public in meaningful ways about the karst landscape in which we live in this area of Kentucky,” Dr. North said.
Geography and Geology Department Head Dr. David Keeling noted that “understanding the impact of sinkhole collapses in communities around the world is central to the teaching and research mission of the department. The work conducted by Drs. North, Polk, and their colleagues and students is a testament to the important relationships between communities and WKU that have been built in recent years.“
WKU also has worked with the City of Bowling Green and other partners to provide educational materials and information for the public to help in protecting these fragile landscapes and reduce the risk of damage from potential threats. For information on sinkholes, visit UnderBGKY.org.