Petra disappearing under tourists’ feet
The colorful sandstone walls of an ancient city may disappear under the weight of tourists who wish to see it, according to a geosciences professor. Petra, a World Heritage Site two hours from Amman, Jordan, attracts international tourists, whose numbers have increased nearly tenfold in the past decade. These crowds may be crumbling the site as they breathe, says geosciences professor Tom Paradise. Paradise works with the Petra National Trust — a Jordanian non-governmental organization. He studies the deterioration of the sandstone at Petra, seeking to determine the effects of sandstone composition, climate, sunlight and tourism on the disintegration of the structures. He and graduate student Mick Frus measured the interior humidity of Al-Khazneh — popularized by the movie “Indiana Jones and the Last Crusade.” They found that when 35 or more people occupied the interior for more than five minutes, the humidity levels rose from 40 to 60 percent — enough to cause severe deterioration of the tombs’ internal structure. During the peak tourism season, 35 or more people occupy Al-Khazneh almost all day, Paradise said. “Certain things in Petra have deteriorated more in the past 10 years than in the past two thousand,” Paradise said. Paradise reported his findings to the UNESCO World Congress in Venice, Italy, last year. Based on these concerns, the Ministry of Antiquities in Jordan closed the interior of Al-Khazneh to tourists in the summer of 2001.