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The Great Pyramid of Egypt and other ancient monuments of Giza exist on an isolated strip of land on the edge of the Sahara Desert.
The inhospitable location has long intrigued archaeologists, some of whom had found evidence that the Nile River once flowed near these pyramids in some way, facilitating the construction of the landmarks starting 4,700 years ago.
Using satellite imagery and sediment core analysis, a new study published Thursday in the journal Communications Earth & Environment mapped a dry branch of the Nile 64 kilometers (40 miles) long, long buried under farmland and desert.
“Even though many efforts have been made to reconstruct the early Nile waterways, they have largely been confined to collecting soil samples from small sites, which has led to the mapping of only fragmented sections of the ancient Nile canal systems. ,” said the study’s lead author. Eman Ghoneim, professor and director of the Drone and Space Remote Sensing Laboratory in the department of Earth and ocean sciences at the University of North Carolina at Wilmington.
“This is the first study to provide the first map of the long-lost ancient branch of the Nile River.”
Ghoneim and his colleagues refer to this extinct branch of the Nile River as Ahramat, which means pyramids in Arabic.
The ancient waterway would have been about 0.5 km wide (about a third of a mile) and had a depth of at least 25 meters (82 feet) – similar to the contemporary Nile, Ghoneim said.
“The large size and extent of the Ahramat Branch and its proximity to the 31 pyramids in the study area strongly suggest a functional waterway of great importance,” Ghoneim said.
She said the river would have played a key role in the transportation by ancient Egyptians of the enormous amount of building materials and workers needed to build the pyramids.
“Furthermore, our research shows that many of the pyramids in the study area have (a) causeway, a ceremonial elevated walkway, that runs perpendicular to the course of the Ahramat arm and ends directly at the river bank.”
Hidden traces of a lost waterway
Traces of the river are not visible in aerial photos or optical satellite images, Ghoneim said. In fact, she just detected something unexpected while studying satellite radar data from a wider area in search of ancient rivers and lakes that could reveal a new source of groundwater.
“I’m a geomorphologist, a paleohydrologist who studies landforms. I have that kind of trained eye,” she said.
“When working with this data, I noticed a very obvious arm or river bank of sorts, and it didn’t make sense because it’s so far from the Nile,” he added.
Born and raised in Egypt, Ghoneim was familiar with the cluster of pyramids in this area and always wondered why they were built there. She asked the National Science Foundation for further investigation, and geophysical data obtained at ground level using ground-penetrating radar and electromagnetic tomography confirmed that it was an ancient branch of the Nile. Two long earth cores that the team extracted using drilling equipment revealed sandy sediments consistent with a river channel at a depth of about 25 meters (82 feet).
It is possible that “countless” temples are still buried beneath agricultural fields and desert sands along the bank of the Ahramat Branch river, according to the study.
It is still unclear why this branch of the river dried up or disappeared. Most likely, a period of drought and desertification swept sand into the region, silting up the river, Ghoneim said.
The study demonstrated that when the pyramids were built, the geography and riverscapes of the Nile differed significantly from today, said Nick Marriner, a geographer at the French National Center for Scientific Research in Paris. He was not involved in the study, but conducted research into the river history of Giza.
“The study completes an important part of the past landscape puzzle,” Marriner said. “By putting these pieces together, we can get a clearer picture of what the Nile floodplain was like at the time of the pyramid builders and how the ancient Egyptians took advantage of their environments to transport building materials for their monumental construction ventures.”
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