Little by little, Hawaii’s iconic beaches are disappearing.

Most beaches on the state’s three largest islands are eroding, and the erosion is likely to accelerate as sea levels rise, the United States Geological Survey is reporting.

Though average erosion rates are relatively low — perhaps a few inches per year — they range up to several feet per year and are highly variable from island to island and within each island, agency scientists say. The report says that over the last century, about 9 percent of the sandy coast on the islands of Hawaii, Oahu and Maui has vanished. That’s almost 14 miles of beach.

The findings have important implications for public safety, the state’s multibillion-dollar tourism economy and the way of life Hawaiians treasure, said Charles H. Fletcher, who led the work for the agency.

“This is a serious problem,” said Dr. Fletcher, a geologist at the University of Hawaii at Manoa.

Sea level does not rise uniformly around the world, and so far, Dr. Fletcher and other geologists said in interviews, Hawaii has escaped some of the rise that has occurred elsewhere as earth’s climate warms. But that situation is unlikely to continue, the report says.