Why is ground subsiding at Persepolis?

The Geological Survey of Iran (GSI) has been conducting an investigation into the exact cause(s) of land subsidence and fissures on the premises of Takht-e Jamshid [Persepolis] and Naqsh-e Rustam in southern Iran.

The head of the Geology Management and Mining Exploration in South (Shiraz) made the remark on Sunday in an interview with the Islamic Republic News Agency (IRNA) and blamed the sinking of the Earth’s surface on unrestrained exploitation of groundwater in the region. The following is the translation of Tahmoures Yousefi’s remarks in the interview followed by experts’ views:

Tahmoures Yousefi said that the current cracks come after similar cracks developed ten years ago in the eastern wing of the Rahmat Mountain where Persepolis is located, blaming the land-surface movement and the cracks on runaway water withdrawal in the area.

The Geological Survey of Iran has put on its agenda a study into the causes of this geological phenomenon and has installed and activated navigation systems such as GPS devices and stations in the historic area, he added.

Yousefi went on to say that the land subsidence and cracks are being studied in these stations and the earth’s frequencies are being monitored there. He also said that the subsidence and cracks in the areas surrounding Takht-e Jamshid are alarming, adding this historic building is in danger [of being destroyed] and we need to work out solutions to tackle the problem.

Experts say that it takes national determination to counter land subsidence around Takht-e Jamshid which is a World Heritage Site. Officials in Fars Province blame unrestrained withdrawal of groundwater for a looming crisis in the province and say that it could cause irreparable losses to people’s lives there.

Land subsidence and sinkholes are natural phenomena which happen gradually and pose a major threat to nature in the long run. The plain surrounding Takht-e Jamshid has developed cracks and sinkholes thanks to the drought which has affected the region and unchecked withdrawal of groundwater.

Prolonged dry spells in Fars Province have greatly concerned officials, people and those interested in cultural heritage. According to Persepolis.ir, land subsidence in Takht-e Jamshid has raised red flags and those in charge should take serious measures to minimize the natural hazards of the geological phenomenon.

[Persepolis was founded by Darius of Achaemenid in 521 BC, and was the dynasty’s political and religious capital until the decline of the empire in 331 BC. UNESCO declared the ruins of Persepolis a World Heritage Site in 1979.]