HILO, Hawai'i — Visitors to Hawai'i Volcanoes National Park who build small rock stacks as a show of respect for Hawaiian deities or the power of Kilauea are doing nothing more than tampering with potential scientific evidence of long-ago eruptions and should stop, park rangers and volcano scientists said.

Kupuna Pele Hanoa, 82, said the misguided practice is akin to sacrilege, since the national park contains many sites considered sacred to Native Hawaiians.

"That's desecrating, because we don't want those rock pilings put up all over the place ... ," Hanoa said. "That's desecration of our culture."

Scientists warn that moving rocks around makes scientific research more difficult, and park rangers say the rock piles alter the natural setting, violating both federal law and the golden rule of national parks that visitors should "take only pictures and leave only footprints."

There are 2.5 million visitors to the Big Island park each year. The stacks of rocks are concentrated at Halema'uma'u Crater, the Southwest Rift Zone's 1971 flow and the 1982 lava flow, officials said.

Similar piles of three or more stones in graduated sizes can be seen at other scenic and historic sites throughout the state, and it's unclear how the practice started. It probably means different things to different visitors, but park ranger Mardie Lane said they trigger an obvious "copy cat" effect: Leave one stack standing for a while and more piles spring up around it.

That means the park must quickly assign staff to dismantle the rocks to prevent more from dotting the landscape.

A statement released yesterday by the U.S. Geological Survey, which runs the Hawaiian Volcano Observatory within the national park, notes that study of the location of specific types of rocks blasted out of Kilauea helped scientists to deduce that the volcano had a long history of explosive eruptions. But when rocks are moved, evidence of past eruptions is altered and "the construction of rock piles erases geologic history," the statement said.

In some cases, visitors are even prying rocks from lava flows to build the stacks, causing even greater damage.

Hanoa, who was born and reared in Ka'u, said visitors to the volcano have been making rock piles around the park for decades.

The park's committee of cultural advisers urged officials to do something about it, and Hanoa wants tour bus drivers to warn their passengers that stacking rocks is disrespectful because the piles don't belong there.

Hawai'i Volcanoes National Park is planning a campaign to educate visitors and tour operators about the importance of preserving the area's natural beauty, and plans are under way for an informational flier. Advisory signs will be posted where rock piles are most common, and temporary exhibits at the Kilauea Visitor Center and Jaggar Museum will discourage stacking.

"Visitors can help protect the park's dynamic landscape by leaving everything — even the rocks — in its rightful place," said Park Superintendent Cindy Orlando.

National park officials warned that federal law prohibits "possessing, destroying, injuring, defacing, removing, or disturbing from its natural state all mineral resources" in national parks.

The park also warns that those who insist on stacking rocks could be charged with a misdemeanor punishable by up to six months in jail and a $5,000 fine.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.