By John Ostapkovich

PHILADELPHIA (CBS) — Pennsylvania figures prominently among places that have sinkholes.

TV coverage of the fatal sinkhole in Florida often included a map showing Pennsylvania as another place where the ground could open up.

Temple Geology Professor Laura Toran says sinkholes can occur in areas with an easily dissolved rock called karst and plenty of subterranean water.

“Karst features are underground. Sinkholes clue us in that they’re there, and they’re interesting in and of their own right 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,” Toran explained.

The Pennsylvania karst feature map shows nothing in Philadelphia, but a line of high karst presence running from northern Lancaster County to Northampton County, north of Allentown, a smaller line in Chester and Montgomery Counties and also near State College.