Harrat Rahat

Harrat Rahat is a vast volcanic field in the Kingdom of Saudi Arabia; its lava flows extend from the north of Makkah and end at Madinah. It contains lavas formed over widely separated periods, from millions of years ago to the last volcanic eruption, which appeared in the southeastern corner of Madinah in 654 AH. [1]

It is one of the largest volcanic fields in the Kingdom, and its recent volcanic activity is concentrated in the northern part, which lies along the southern and eastern edges of Madinah. [2]

The field extends from the north of the Makkah Region to the Madinah Region, and its lava flows, of differing ages, stand side by side across adjacent geological eras: a flow whose volcano erupted millions of years ago, another that erupted thousands of years ago, and, tens of meters away, a flow formed in the last volcanic eruption in the southeastern corner of Madinah in 654 AH. [1]

The field aligns with the northwest trend of the Najd fault system, like the harrats of Uwayrid, Hutaymah, and Khaybar, and its volcanoes spread along a single north-to-south axis, the Makkah–Madinah volcanic line. [3]

The distribution of the harrats in the Kingdom is linked to intense fracturing movements that accompanied the opening of the Red Sea rift, which originated at the end of the Oligocene or the beginning of the Miocene about 25 million years ago; these harrats cover large areas of the western part of the Arabian continental shelf, estimated at about 180,000 square kilometers. [3]

Harrat Rahat, like Khaybar and Kishb, contains volcanic cones of varied rock composition, ranging from trachyte and phonolite to rhyolite. [3]

The northern edge of Harrat Rahat comprises 644 craters in the form of volcanic cones, the area where recent volcanic activity is concentrated, along the southern and eastern edges of Madinah. [2]

The field alone holds about 700 volcanic cones, and the basaltic lava flows in the Madinah Region cover vast areas, reaching 24% of its area. [4]

Geological maps and rock-age estimates show that the last volcanic eruption occurred south of Madinah in 1256 CE (654 AH) near the Al-Ayni area, where lava covered the eastern edge of Madinah and issued through ground fissures, preceded by earthquakes that lasted from four to five days. [2]

Among the field's features and geological landmarks are long tunnels formed when molten magma flowed over the surface, its top cooled into a crust, and the hot molten interior remained within until it vanished, creating those tunnels of varying sizes. [2]

Jabal Al-Malsa, which rises 916 meters above sea level, is an extinct volcano with a large crater at its summit, and the lava flowing from it formed tunnels, pillars, and unusual natural scenery. [4]

The Saudi Geological Survey monitors and studies seismic activity and continuously monitors volcanic and seismic activity around the harrats in the Kingdom; it operates the most advanced seismic monitoring networks in the Middle East and conducts studies and research in seismology and volcanology. [2]

The Survey presented to the Governor of the Madinah Region its efforts in seismic and volcanic studies, and the technical studies concerning the possibility of establishing an educational and tourist volcanic park that embodies the natural heritage of the region and provides an open educational space for researchers and enthusiasts. [7]

Researchers at the symposium “Harrats and Mountains of Madinah,” held by Taibah University in cooperation with the Madinah Studies and Research Center, recommended avoiding construction and urban expansion near seismically active faults, conducting intensive studies to assess the geothermal reservoir beneath northern Harrat Rahat and the possibility of generating electricity from it, and not removing the volcanic craters around Madinah in order to preserve the distinctive geological features. [8]

Rugged terrain did not prevent people from adapting to Harrat Rahat and living within it, benefiting from its water reserves and the fertility of its soil; agricultural oases with deep historical roots emerged, and the tail-shaped stone structures and stone circles attest to the antiquity of human settlement in the field. [1]

The field's basalt rocks provided the first building materials, for from them people built houses and forts and carved their tools, such as the quern. [1]

Harrat basalt was approved as the first Saudi heritage stone on the global heritage stone list of the International Union of Geological Sciences (IUGS), and the harrats of the Madinah Region preserve prominent evidence of this geological heritage, among them Harrat Rahat and Harrat Khaybar. [6]

The Supreme Commission for Tourism sought to open the first geological park in the Kingdom by developing the Harrat Rahat project 19 kilometers southeast of Madinah, to benefit from its distinctive natural components. [4]

The Saudi Commission for Tourism and National Heritage, represented by its Investment and Tourism Development Sector, signed a joint cooperation agreement to prepare a specialized study of Harrat Rahat in the Madinah Region with King Abdulaziz University, represented by its Geological Hazards Research Center; it included identifying the most important tourist landmarks and selecting them in line with the global criteria for geological parks, preparing plans and interpretive panels, protecting geological features, and investigating volcanic hazards in the field. [5]

Q: Where is Harrat Rahat located? A: It extends from the north of Makkah to Madinah, and its lava flows and craters lie in the western part of the Kingdom of Saudi Arabia. [1][3]

Q: When did the last volcanic eruption in Harrat Rahat occur? A: It occurred south of Madinah in 1256 CE (654 AH); lava covered the eastern edge of Madinah, and earthquakes lasting from four to five days preceded it. [2]

Q: How many craters and volcanic cones does Harrat Rahat contain? A: Its northern edge comprises 644 craters in the form of volcanic cones, and the field alone holds about 700 volcanic cones. [2][4]

Q: What are the most prominent geological landmarks of Harrat Rahat? A: Its geological landmarks include the long tunnels formed by the flow of magma and the cooling of its surface, Jabal Al-Malsa at 916 meters, and volcanic cones of varied rock composition. [2][3][4]

Q: How are volcanic and seismic activity monitored in Harrat Rahat? A: Through the continuous monitoring carried out by the Saudi Geological Survey, which operates the most advanced seismic monitoring networks in the Middle East. [2]

Harrat Rahat combines its extent from the north of Makkah to Madinah [1], its volcanic features of craters, cones, and tunnels [2][4], the evidence of ancient human settlement within it [1], and the efforts of monitoring, study, and protection of geological features, including the approval of harrat basalt as the first Saudi heritage stone [2][4][5][6][7][8].

Related topics on the platform include Harrat Al-Harrah Protected Area and Sarawat Mountains, and interest in the field is connected to environmental protection within the Saudi Green Initiative.