For a long time, the Arabian desert was the perfect synonym for drought, extreme temperatures and vast expanses of sand. However, this image began to crumble after recent international research questioned what was thought about its climatic history. This is because a multidisciplinary team found geological evidence pointing to a surprisingly different past, where water played a central role in transforming the environment.
Why is it believed that there was a deep lake in the Arabian desert?
To understand this statement, one must go to the region known as Rub’ al-Khali, or The Empty Quarter, located in the south of the Arabian Peninsula. This area, covered by dunes and with little vegetation, is part of the Arabian Desert, one of the most arid areas on the planet. Covering an area of approximately 650,000 square kilometres, it was thought that its aridity had been a constant for thousands of years. A group of researchers from different scientific institutions, including the University of Geneva and King Abdullah University of Science and Technology, have found evidence pointing to a radically different scenario during a period between 11,000 and 5,500 years ago.
Geological analyses have identified a now-extinct hydrographic network and the existence of a lake up to 42 metres deep in the middle of the Arabian desert. The discovery thus suggests that Rub’ al-Khali may have been, for millennia, an area with abundant water resources. The Rub’ al-Khali desert, part of Green Arabia This lake would have appeared during a climatic phase called Green Arabia. This period was characterised by increased rainfall caused by the northward expansion of the African and Indian monsoons.
These climatic changes allowed the development of savannahs, pastures and permanent watercourses in areas that are now desert. According to Abdallah Zaki, lead author of the study and researcher at the University of Texas, this body of water was part of an active river basin that changed the morphology of the terrain. This is a palaeogeographic reconstruction that alters the traditional view of Rub’ al-Khali as a lifeless swamp. The researchers analysed satellite images, sediments and landforms to determine the location and characteristics of this lake. The evidence also indicates the presence of seasonal rivers that fed the lake system.
What does the discovery of water in this Arabian desert symbolise for archaeology?
The availability of water not only altered the physical landscape of the Arabian desert, but also favoured human occupation. Stone tools and other archaeological remains have been found in different areas of the Rub’ al-Khali. This suggests that the humid ecosystem allowed for activities such as hunting, gathering and even early forms of herding.
Michael Petraglia, a professor at Griffith University, argues that this transformation facilitated the expansion of human communities into regions that are now completely inhospitable. Subsequent climate change, which occurred about 6,000 years ago, brought an end to the rains and triggered a process of desertification that continues to this day. Since then, the area has once again become an extreme desert, where temperatures can exceed 50 °C and dunes reach heights of over 300 metres. Despite its aridity, the Rub’ al-Khali is home to small forms of life adapted to the environment, such as rodents, arachnids and xerophytic plants.
The current geological and economic impact of the Rub’ al-Khali
In addition to its climatic and historical interest, the Arabian desert has significant economic relevance. Beneath its dunes lies one of the largest oil fields in the world. Shaybah, in the heart of the Rub’ al-Khali, is a centre for light oil extraction, while the Ghawar field extends partially across its northern zone. Ecologically, this region is part of the Arabian and Sinai desert and xerophilous mountain ecoregion. Progressive desertification has reduced the possibility of stable life in the area, although some tribes continue to inhabit certain areas, especially in the Najran region, connected by road to extraction points and water sources.
Despite its size, the Arabian desert was little explored until the 20th century. The first expeditions documented by Europeans were carried out in 1931 and 1932, and between 1946 and 1950 Wilfred Thesiger made several crossings, contributing to the partial cartography of the area. Recently, GPS-guided tours have been organised to cover parts of the Rub’ al-Khali, although it remains a place of limited access. In popular culture, this desert appeared in 2011 in the video game Uncharted 3: Drake’s Deception for PlayStation 3, where its imposing landscape and natural hostility are portrayed.
