An Ohio State University study suggests that as sea levels rise a predicted 23 inches during the next 100 years, coastal communities could lose up to 50 percent more of their fresh water supplies than previous research has indicated.

Scientists previously assumed that as saltwater moved inland, it would penetrate underground only as far as it did above ground. But the new research shows when saltwater and fresh water meet, they can mix in complex ways. In some cases, a zone of mixed, undrinkable brackish water can extend 50 percent farther inland underground than it does above ground.

"Most people are probably aware of the damage that rising sea levels can do above ground, but not underground, which is where the fresh water is," said Associate Professor Motomu Ibaraki. "With this work, we are pointing out another way that climate change can potentially reduce available drinking water."

Ibaraki and graduate student Jun Mizuno presented the study during last month's Denver meeting of the Geological Society of America.