Machu Picchu's slide

Is Machu Picchu falling? A team of Japanese geologists has concluded that it is. So as my three kids hop like squirrels from one ancient stone terrace to another, I have to wonder: Should I tell them to go easy on the grande dame of pre-Columbian ruins?

Machu Picchu - the great Inca site built before the arrival of the Spanish in the 16th century, lost to the jungle for four centuries and then discovered by American archaeologist Hiram Bingham in 1911 - sits magnificently in the saddle between two green jungle peaks. The site is sans pareil, more than 1,200 feet straight up from a spectacular horseshoe bend in the roiling, cafe-au-lait waters of Peru's Urubamba River.

But now, these Japanese rock men say the whole mysterious collection of temples, palaces, and agricultural terraces could go crashing into the Urubamba without a moment's notice.

As reported in the March 10 issue of Britain's New Scientist magazine, the team from the University of Kyoto reports that part of Machu Picchu is sliding downhill at a rate of one centimeter, or 0.4 inches, per month. The sliding, the geologists warn, could produce rockslides and a ground collapse that would destroy Peru's top tourist draw, a UNESCO world heritage site.

The rate of slippage "is quite fast," says geologist Kyoji Sassa in New Scientist, "and it's a precursor stage of a rockfall or a rockslide."

Almost a half-inch a month! Imagining it, I believe I feel the earth tremble as my 10-year-old jumps down from a resting perch atop a wall of meticulously cut and fitted Inca stones. "Let's go easy on the jumping," I call out, "Didn't you feel that shaking?"

Dozens of Inca Trail trotters and hundreds of bus-borne tourists light upon the site the same day as our gaggle of seven gringos, but if any of them is as worried about the imminent collapse as I am, it doesn't show.

The American visitors I speak to have never heard of the Japanese study, and the Europeans, fat guidebooks in hand, seem more interested in details of Inca life than in Japanese scientists.

The many Peruvian guides prowling the site don't bring up the scientific report with their awe-struck charges, and our guide tells me why.

"People here say this whole idea of Machu Picchu sliding down the mountain is probably Fujimori's doing," says Maria Elena Santos, an approved Machu Picchu guide who lives in the nearby jungle outpost of Aguas Calientes. The allusion is, of course, to former President Alberto Fujimori, who fled to Japan last December as a political scandal threatened the Japanese-descended leader with his own version of a foundational collapse.

As Mr. Fujimori has in a matter of months gone from revered leader to scapegoat for absolutely everything else wrong with Peru, there's no surprise that he's suspected of being at the bottom of the Machu Picchu study as well. "It could be that Fujimori sent over those Japanese specialists," Ms. Santos surmises, "with the intent of damaging tourism and destabilizing the country."

The theory fits well with Peru's current mindset, but not everyone in the country buys it. For one thing, says renowned Peruvian archaeologist Federico Kauffman Doig, the Incas themselves knew there were geological challenges to the site, and more recent Peruvian studies have also sounded alarms about the evolution of fissures under the ruins.

"Machu Picchu is too important. We need to take all of these warnings seriously rather than hiding our head like an ostrich," says Mr. Kauffman, interviewed at his home in Lima.

Kauffman says the Incas were well enough aware of the dangers of "tectonic fissures" on the site to take precautions: They filled them up with rocks. Today, the visitor can pick out plainly the fault that runs down the middle of the ruined city like a band cut around a totem pole.

Despite this, the government dismissed the Japanese warnings, basically responding that if Machu Picchu hadn't collapsed in 600 years it was unlikely it would now. "That's a worrisome reaction," Kauffman says.

The government didn't jump to respond to the Japanese study, but it has taken some steps to mitigate tourism's impact on the fragile site. The number of hikers on the famous Inca Trail leading into Machu Picchu is now limited, and the entrance fee to the site was recently doubled to $20. With more than 300,000 tourists visiting this once isolated city every year, the National Institute of Culture says it is studying Machu Pichu's tourism carrying capacity.

"In Inca times, 500 people at most lived in Machu Picchu and farmed the terraces," says Kauffman. "And they were generally small people, barefoot or with soft sandals, and they weren't spending all day climbing all over the city like the tourists today."

I think of those words as my kids, in their indestructible hiking boots, investigate a row of roofless, single-room Inca houses. The dirt floor tells of the passage of thousands of Vibram soles before theirs.

Given the importance of Machu Picchu to the world, Kauffman says its future shouldn't be left to hazard. He suggests an international commission, headed by UNESCO, to study the rate of slippage - and to propose remedial measures if necessary. "[UNESCO] is involved in detaining the leaning process of the Pisa tower," he notes. "They have expertise in this kind of thing."

Kauffman, who has written extensively about Peru's pre-Columbian cultures, says Machu Picchu deserves special attention in today's world for what it meant to the inhabitants of yesterday's: "It was above all a center of thanksgiving to the Earth."

Treading - as lightly as possible - on this manmade wonder, and taking in the breathtaking vistas of the setting, it's easy to see why the Incas assigned that purpose to this gift of a site.

(c) Copyright 2001. The Christian Science Monitor