The recent sinkhole tragedy in Florida has called attention to the fact that Pennsylvania’s geology makes it among the leaders in sinkholes. Sinkholes occur in areas with an easily dissolved rock called karst and plenty of subterranean water, says Temple geologist Laura Toran. “Karst features are underground,” she said. “Sinkholes clue us in that they’re there, and they’re interesting because they can transfer contaminants much faster than regular aquifers, and that can be scary, so we have to keep track of where they are.”