Saudi Arabia’s Empty Quarter was once covered by a vast lake, say researchers

A vast lake once covered part of Saudi Arabia’s Rub’ Al-Khali desert researchers have found, in a discovery that challenges conventional views of the Arabian Peninsula as eternally arid.

The findings have been published in Communications Earth & Environment. They reveal that around 9,000 years ago, a 1,100km² lake — comparable in size to Lake Michigan-Huron — filled a now-barren basin in the heart of the “Empty Quarter”, one of the driest regions on Earth.

“Based on a series of ages, it appears the lake peaked about 9,000 years ago during a wet Green Arabia period that extended between 11,000 to 5,500 years ago,” said lead author Dr Abdallah Zaki of the University of Geneva.

The Empty Quarter was not always barren — a study by @KAUST_News and other universities reveals that this region once had a lake and river system https://t.co/nPkqyagyXY

— Arab News (@arabnews) April 9, 2025

Driven by intensified African monsoon rains, the lake eventually breached, carving out a 150km valley through the desert floor. These conditions, say scientists, would have transformed the landscape into a savannah dotted with grasslands, wetlands and wildlife such as elephants and hippos.

“The formation of lake and riverine landscapes, together with grasslands and savanna conditions, would have led to the expansion of hunting and gathering groups and pastoral populations,” explained Michael Petraglia, Director of Griffith University’s Australian Research Centre for Human Evolution.

However, by 6,000 years ago, rainfall levels collapsed, ushering in the desertification of the region and forcing human groups to migrate to more hospitable zones.

The discovery adds to a growing body of evidence that Arabia’s deep past was far wetter and more habitable than today, and that the Empty Quarter — now dominated by scorching dunes — was once a cradle of human and animal life.

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